Vizio no pic

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ote:

-Del wrote:

4, Stu jax> > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > hi group, i'm working on a Vizio 39 Tes

la model..E470va, so it's a 47 inch, I have no picture no audio, I do get t he correct voltages from the power supply, I changed the main board, and na da.. when I turn the tv on, with the back cover off, I see a led ON THE INV ERTER BOARD turn blue twice then turns off, I am suspecting the tcon board or also called this TQAPT5K00901 TQAPT 5k009 01 LCD PC Board Unit Motherboa rd. this is a lcd tv, I do have backlights, and a faint glow on the screen from the backlights... any help on this problem, will be taken seriously. T hanks,Stan...

ight and extinguish if the inverters are normal.

or still have a bad main. There are no new parts available for these, so any board you buy from *any* supplier is suspect. A legitimate ebay seller who sells a board from a TV with a cracked screen but otherwise verifiable as fully functional is a fair bet, but we still don't know if the donor ha d a picture, even if it did also have a cracked screen. Other internet boa rd sellers are just recyclers who sell boards without testing, but they off er generous return policies and long warranties.

th normal backlights) is to scope the differential signals coming out of th e main at the LVDS plug to the TCON. These are digital signals and are jibb erish, but if they're there, the main is usually good. While scoping, it's helpful to push the TVs menu button and watch for any activity on the diffe rential outputs. If only DC appears on the LVDS output connector, you still have a bad main.

y removing either of the two ribbon connectors going to the display from th e TCON and see if you get half a pix. If not, reconnect the ribbon and rem ove the other. If you get half a picture from either attempt, you've got a bad display. Still no pic? Prob bad TCON.

s you can check, but if it's open, usually a bad multi layer chip cap has s horted although there could also be a bad IC. If the fuse is good, you can check for DC at various points on the board if marked. If nothing is mark ed, look for small round inductors that identify the handful of buck conver ters that normally populate TCONs. There should be DC voltages on them and can vary from 1.2 to 24V depending on design. If any are missing with the output ribbons disconnected, you have a bad TCON.

. I hooked up a scope 5v ch1, on dc coupling I got dc differential signals with the menu button pressed on some pins and not data on others same resul ts with ac coupling, if the tcon board was good was i supposed to see an AC siganl.? and with the ribbons removed no pic on either side.. bad tcon boa rd..?

the TCON fuse.

v with a 10X probe and maybe .5ms for the horizontal - neither setting is c ritical. The signals are digital data and not on every pin. What I've fou nd over the years is that any data visible with a known good input source o r menu activation (which guarantees *something* should appear on the screen ) means the main is good. Of course, those that produce a picture with iss ues like off colors, pixelization, gamma errors etc. could be the main and it's nearly impossible to tell if the main or the TCON are causing those pr oblems by scoping the signals. But generally, if you have differential sig nals to the TCON but no picture, the main is good.

s like you have a bad TCON. Pull the shield off and look for any shorted m ulti layer capacitors. These are small SMD caps, have no markings, and are invariably brown in color. The ones most suspect are the ones that are si de by side in a parallel arrangement. If one of these caps short, the buck regulator in the circuit will shut down. The problem is that one shorted cap may be paralleled by several and up to a dozen, so picking the offendin g shorted cap out can take some time.

d good TCON in the shop.

er side. i didn't get a chance to further test/scope the tcon board, my tru ck is in need of repairs. i will post as soon as i can.

ds, although they're shaped like any other SMD resistor or capacitor. They tend to be gray in color, have no markings, and should read zero ohms. The y may or may not have voltage on them depending on where in the circuit the y are.

o see what the board looks like, and it appears there are two different ver sions of that TV depending on the display installed. One version has the m ain board connected directly to the TCON, the other has the main board conn ected to an FRC board which then feeds the TCON. Both versions use a diffe rent TCON.

ramic surface mount fuse marked 3A which should have 12V on it. You will al so have the FRC board which is an equal possibility as the TCON board for c ausing no pix.

er it that covers most of the components and I'll need to see a picture of the board without the shield to point out the fuse. Follow the leads from connector CN4402 under the shield and you should find the fuse. It might b e ceramic like the other one or look like a smd resistor. Most non-ceramic fuses used in these types of boards have a single letter on them indicatin g current. The larger white ceramic ones have the actual current printed numerically on them.

/imgur.com/) and post the link, or you could send them to my spam email (wh ich I monitor): ohger1s/at/aol/dot/com

k (same TV, smaller screen). The kit I have uses a FRC board and smaller T CON with no shield.

If you have the larger TCON with the large shield over the board and no FR C board, then you'll have to remove the shield on the TCON.

e actual picture.

n both sides of it when the TV is on. If the 12V is missing, unplug the LV DS and check that FB to ground for resistance. Should read no less than 10 K ohms to ground. If the resistance on that FB is showing low ohms, the TCO N has a shorted component on it.

n't, check the input pin for 3.3. That series of tab regulator is a common problem on main boards,FRC boards, and TCONs.

8 volts on the other (typical Vizio reg voltages) measured at the tabs.

re should be 12V and 5V on that connector. If either/both are missing, che ck for shorts to ground as you did with the ferrite bead. If there are no shorts and no voltages, I'd suspect the main.

he 12 volts is on the ferrite bead, and you can view differential activity on the LVDS connector with a scope, and you can't get a half picture with e ither display ribbon removed, indications are very strong towards the TCON/ FRC board.

i got zero ohms, so it's a bad tcon board, that's shorted.. ?

make sure you have 12V on the harness. Most of the time, a shorted TCON wi ll cause the 12V supply that feeds it to shut down, but there's a chance th e 12V source could have been damaged as well. If there's no 12V, check the main for an open surface mount fuse (these are generally white on Vizios w ith a letter on them).

ON should get you going. If you have the time, you can check for shorted c hip caps. These are brown, about the size of that ferrite bead, and have n o markings. One way is to feed a current regulated supply set to 2 amps ri ght at that ferrite bead to force feed the TCON to see what gets hot. A fr ost covering from a can of freeze spray will often give you a visual of wha t's drawing the current (whatever thaws first).

green wire, 11.98 v on the yellow wire. nothing on the red and orange wires . 5v on brown wire. and just for your info I got a little anxious and order ed the tcon board arrive yesterday, got nothing no pic... the main board is recently purchased also from ebay .. I think i got both from electroparts. .

may have added a problem where none existed before.

r wire connector (which will have 12V , 5V, and ground) and the larger LVDS harness CN4404 where the ferrite bead smd component is.

n't know if they're sourced from the same 12V supply or not, but you should have 12V on that ferrite bead. Your earlier post said you did not have 12 V on that ferrite bead and were reading a short to ground. Is this correct ? If you unplug the LVDS harness, the short on the ferrite bead to the TCO N ground will either go away or remain. If it goes away, the problem is on the main. If it stays, the short is on the TCON.

regardless of where they're purchased. There are no new parts available fo r these, so any part you buy is from a recycled donor, and none of these ma ss parts sellers check them. They strip the carcass of it's boards, sell t hem, and replace or refund the money if they get a complaint. If the donor TV failed with the same defective board you have, you'll have the same issu e.

the customer, and why we repair about 95 percent of the boards we see.

t these guys are technicians who will only sell verified boards.

ace or refund without question.

tcon board.?

d the one you just bought are showing a low ohm short to ground as read on that ferrite bead near the LVDS cable?

e tcon on cn702..

disconnected from the TCON. IIRC, the CN702 connector goes to the power su pply, not the main. Is there 12V on the LVDS connector when it is lifted o ff the TCON?

OK, I miss read your post, I measured the fb on v scale, now i measured on ohms scale and with the tv on I get OL with the backlights on, when the bac klights go out the fb reads lights a cap starts high 320k on both sides, th is is with the new board recently purchased from ebay.. and what wire am i supposed to get 12v on at lvds connector when i pull it, there's 20-30 wire s..?

Reply to
Stu jaxon
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esla model..E470va, so it's a 47 inch, I have no picture no audio, I do get the correct voltages from the power supply, I changed the main board, and nada.. when I turn the tv on, with the back cover off, I see a led ON THE I NVERTER BOARD turn blue twice then turns off, I am suspecting the tcon boar d or also called this TQAPT5K00901 TQAPT 5k009 01 LCD PC Board Unit Motherb oard. this is a lcd tv, I do have backlights, and a faint glow on the scree n from the backlights... any help on this problem, will be taken seriously. Thanks,Stan...

light and extinguish if the inverters are normal.

y, or still have a bad main. There are no new parts available for these, s o any board you buy from *any* supplier is suspect. A legitimate ebay sell er who sells a board from a TV with a cracked screen but otherwise verifiab le as fully functional is a fair bet, but we still don't know if the donor had a picture, even if it did also have a cracked screen. Other internet b oard sellers are just recyclers who sell boards without testing, but they o ffer generous return policies and long warranties.

with normal backlights) is to scope the differential signals coming out of the main at the LVDS plug to the TCON. These are digital signals and are ji bberish, but if they're there, the main is usually good. While scoping, it' s helpful to push the TVs menu button and watch for any activity on the dif ferential outputs. If only DC appears on the LVDS output connector, you sti ll have a bad main.

try removing either of the two ribbon connectors going to the display from the TCON and see if you get half a pix. If not, reconnect the ribbon and r emove the other. If you get half a picture from either attempt, you've got a bad display. Still no pic? Prob bad TCON.

ess you can check, but if it's open, usually a bad multi layer chip cap has shorted although there could also be a bad IC. If the fuse is good, you c an check for DC at various points on the board if marked. If nothing is ma rked, look for small round inductors that identify the handful of buck conv erters that normally populate TCONs. There should be DC voltages on them a nd can vary from 1.2 to 24V depending on design. If any are missing with th e output ribbons disconnected, you have a bad TCON.

d.. I hooked up a scope 5v ch1, on dc coupling I got dc differential signal s with the menu button pressed on some pins and not data on others same res ults with ac coupling, if the tcon board was good was i supposed to see an AC siganl.? and with the ribbons removed no pic on either side.. bad tcon b oard..?

on the TCON fuse.

0mv with a 10X probe and maybe .5ms for the horizontal - neither setting is critical. The signals are digital data and not on every pin. What I've f ound over the years is that any data visible with a known good input source or menu activation (which guarantees *something* should appear on the scre en) means the main is good. Of course, those that produce a picture with i ssues like off colors, pixelization, gamma errors etc. could be the main an d it's nearly impossible to tell if the main or the TCON are causing those problems by scoping the signals. But generally, if you have differential s ignals to the TCON but no picture, the main is good.

nds like you have a bad TCON. Pull the shield off and look for any shorted multi layer capacitors. These are small SMD caps, have no markings, and a re invariably brown in color. The ones most suspect are the ones that are side by side in a parallel arrangement. If one of these caps short, the bu ck regulator in the circuit will shut down. The problem is that one shorte d cap may be paralleled by several and up to a dozen, so picking the offend ing shorted cap out can take some time.

ied good TCON in the shop.

ther side. i didn't get a chance to further test/scope the tcon board, my t ruck is in need of repairs. i will post as soon as i can.

eads, although they're shaped like any other SMD resistor or capacitor. The y tend to be gray in color, have no markings, and should read zero ohms. T hey may or may not have voltage on them depending on where in the circuit t hey are.

to see what the board looks like, and it appears there are two different v ersions of that TV depending on the display installed. One version has the main board connected directly to the TCON, the other has the main board co nnected to an FRC board which then feeds the TCON. Both versions use a dif ferent TCON.

ceramic surface mount fuse marked 3A which should have 12V on it. You will also have the FRC board which is an equal possibility as the TCON board for causing no pix.

over it that covers most of the components and I'll need to see a picture o f the board without the shield to point out the fuse. Follow the leads fro m connector CN4402 under the shield and you should find the fuse. It might be ceramic like the other one or look like a smd resistor. Most non-ceram ic fuses used in these types of boards have a single letter on them indicat ing current. The larger white ceramic ones have the actual current printe d numerically on them.

://imgur.com/) and post the link, or you could send them to my spam email ( which I monitor): ohger1s/at/aol/dot/com

ock (same TV, smaller screen). The kit I have uses a FRC board and smaller TCON with no shield.

. If you have the larger TCON with the large shield over the board and no FRC board, then you'll have to remove the shield on the TCON.

the actual picture.

on both sides of it when the TV is on. If the 12V is missing, unplug the LVDS and check that FB to ground for resistance. Should read no less than

10K ohms to ground. If the resistance on that FB is showing low ohms, the T CON has a shorted component on it.

esn't, check the input pin for 3.3. That series of tab regulator is a comm on problem on main boards,FRC boards, and TCONs.

1.8 volts on the other (typical Vizio reg voltages) measured at the tabs.

here should be 12V and 5V on that connector. If either/both are missing, c heck for shorts to ground as you did with the ferrite bead. If there are n o shorts and no voltages, I'd suspect the main.

the 12 volts is on the ferrite bead, and you can view differential activit y on the LVDS connector with a scope, and you can't get a half picture with either display ribbon removed, indications are very strong towards the TCO N/FRC board.

, i got zero ohms, so it's a bad tcon board, that's shorted.. ?

d make sure you have 12V on the harness. Most of the time, a shorted TCON will cause the 12V supply that feeds it to shut down, but there's a chance the 12V source could have been damaged as well. If there's no 12V, check t he main for an open surface mount fuse (these are generally white on Vizios with a letter on them).

TCON should get you going. If you have the time, you can check for shorted chip caps. These are brown, about the size of that ferrite bead, and have no markings. One way is to feed a current regulated supply set to 2 amps right at that ferrite bead to force feed the TCON to see what gets hot. A frost covering from a can of freeze spray will often give you a visual of w hat's drawing the current (whatever thaws first).

n green wire, 11.98 v on the yellow wire. nothing on the red and orange wir es. 5v on brown wire. and just for your info I got a little anxious and ord ered the tcon board arrive yesterday, got nothing no pic... the main board is recently purchased also from ebay .. I think i got both from electropart s..

u may have added a problem where none existed before.

our wire connector (which will have 12V , 5V, and ground) and the larger LV DS harness CN4404 where the ferrite bead smd component is.

don't know if they're sourced from the same 12V supply or not, but you shou ld have 12V on that ferrite bead. Your earlier post said you did not have

12V on that ferrite bead and were reading a short to ground. Is this corre ct? If you unplug the LVDS harness, the short on the ferrite bead to the T CON ground will either go away or remain. If it goes away, the problem is on the main. If it stays, the short is on the TCON.

e regardless of where they're purchased. There are no new parts available for these, so any part you buy is from a recycled donor, and none of these mass parts sellers check them. They strip the carcass of it's boards, sell them, and replace or refund the money if they get a complaint. If the dono r TV failed with the same defective board you have, you'll have the same is sue.

or the customer, and why we repair about 95 percent of the boards we see.

but these guys are technicians who will only sell verified boards.

place or refund without question.

e tcon board.?

and the one you just bought are showing a low ohm short to ground as read o n that ferrite bead near the LVDS cable?

the tcon on cn702..

s disconnected from the TCON. IIRC, the CN702 connector goes to the power supply, not the main. Is there 12V on the LVDS connector when it is lifted off the TCON?

n ohms scale and with the tv on I get OL with the backlights on, when the b acklights go out the fb reads like a cap, starts high 320k on both sides, t his is with the new board recently purchased from ebay.. and what wire am i supposed to get 12v on at lvds connector when i pull it, there's 20-30 wir es..?

Reply to
Stu jaxon

s disconnected from the TCON. IIRC, the CN702 connector goes to the power supply, not the main. Is there 12V on the LVDS connector when it is lifted off the TCON?

n ohms scale and with the tv on I get OL with the backlights on, when the b acklights go out the fb reads lights a cap starts high 320k on both sides, this is with the new board recently purchased from ebay.. and what wire am i supposed to get 12v on at lvds connector when i pull it, there's 20-30 wi res..?

OK, let's go back one step at a time...

With the TV off and your meter on ohms, what is the resistance at the fb to ground?

With the TV still off and the LVDS harness unplugged from the TCON and your meter on ohms, what is the resistance on the fb to ground?

With the TV on and your meter now set to DC volts, what voltage are you rea ding at the fb?

Do not attempt to read ohms with the TV running!

If you are getting 12V on the fb, you don't need to look for the voltage at the LVDS harness. But if there is no voltage at the fb, then we want to l ook for it with the TCON disconnected by reading it at the unplugged LVDS h arness.

With the LVDS harness unplugged, you should be able to read 12V on several pins. The correct pins will be physically close to the fb, in other words, the first couple of pins at the side of the harness that would be close to the fb.

Perform all those tests using your original TCON and your replacement board . If there is a difference between them, then answer for both.

Reply to
John-Del

is disconnected from the TCON. IIRC, the CN702 connector goes to the powe r supply, not the main. Is there 12V on the LVDS connector when it is lift ed off the TCON?

on ohms scale and with the tv on I get OL with the backlights on, when the backlights go out the fb reads lights a cap starts high 320k on both sides , this is with the new board recently purchased from ebay.. and what wire a m i supposed to get 12v on at lvds connector when i pull it, there's 20-30 wires..?

to ground?

ur meter on ohms, what is the resistance on the fb to ground?

eading at the fb?

at the LVDS harness. But if there is no voltage at the fb, then we want to look for it with the TCON disconnected by reading it at the unplugged LVDS harness.

l pins. The correct pins will be physically close to the fb, in other word s, the first couple of pins at the side of the harness that would be close to the fb.

rd. If there is a difference between them, then answer for both.

with the new tcon board installed, ON FB to ground both sides are .3-4m ohm s. with lvds unplugged 400k one side other 300k ohms.. TV on testing pins c losest to FB the highest was 1.4v - 0v..

Old Tcon board... .4 ohms both sides,.. lvds unplugged .3 ohms... TV on .2m v on FB TV lvds unplgged pins closest to FB 2v- .3 mv.. hope i covered eve rything...

Reply to
Stu jaxon

it is disconnected from the TCON. IIRC, the CN702 connector goes to the po wer supply, not the main. Is there 12V on the LVDS connector when it is li fted off the TCON?

ed on ohms scale and with the tv on I get OL with the backlights on, when t he backlights go out the fb reads lights a cap starts high 320k on both sid es, this is with the new board recently purchased from ebay.. and what wire am i supposed to get 12v on at lvds connector when i pull it, there's 20-3

0 wires..?

b to ground?

your meter on ohms, what is the resistance on the fb to ground?

reading at the fb?

e at the LVDS harness. But if there is no voltage at the fb, then we want to look for it with the TCON disconnected by reading it at the unplugged LV DS harness.

ral pins. The correct pins will be physically close to the fb, in other wo rds, the first couple of pins at the side of the harness that would be clos e to the fb.

oard. If there is a difference between them, then answer for both.

4m ohms. with lvds unplugged 400k one side other 300k ohms.. TV on testing pins closest to FB the highest was 1.4v - 0v..
2mv on FB TV on lvds unplgged pins closest to FB 2v- .3 mv.. hope i covere d everything...
Reply to
Stu jaxon

n it is disconnected from the TCON. IIRC, the CN702 connector goes to the power supply, not the main. Is there 12V on the LVDS connector when it is lifted off the TCON?

ured on ohms scale and with the tv on I get OL with the backlights on, when the backlights go out the fb reads lights a cap starts high 320k on both s ides, this is with the new board recently purchased from ebay.. and what wi re am i supposed to get 12v on at lvds connector when i pull it, there's 20

-30 wires..?

fb to ground?

d your meter on ohms, what is the resistance on the fb to ground?

ou reading at the fb?

age at the LVDS harness. But if there is no voltage at the fb, then we wan t to look for it with the TCON disconnected by reading it at the unplugged LVDS harness.

veral pins. The correct pins will be physically close to the fb, in other words, the first couple of pins at the side of the harness that would be cl ose to the fb.

board. If there is a difference between them, then answer for both.

3-.4m ohms. with lvds unplugged 400k one side other 300k ohms.. TV on testi ng pins closest to FB the highest was 1.4v - 0v..

.2mv on FB TV on lvds unplgged pins closest to FB 2v- .3 mv.. hope i cove red everything...

Reply to
Stu jaxon

n it is disconnected from the TCON. IIRC, the CN702 connector goes to the power supply, not the main. Is there 12V on the LVDS connector when it is lifted off the TCON?

ured on ohms scale and with the tv on I get OL with the backlights on, when the backlights go out the fb reads lights a cap starts high 320k on both s ides, this is with the new board recently purchased from ebay.. and what wi re am i supposed to get 12v on at lvds connector when i pull it, there's 20

-30 wires..?

fb to ground?

d your meter on ohms, what is the resistance on the fb to ground?

ou reading at the fb?

age at the LVDS harness. But if there is no voltage at the fb, then we wan t to look for it with the TCON disconnected by reading it at the unplugged LVDS harness.

veral pins. The correct pins will be physically close to the fb, in other words, the first couple of pins at the side of the harness that would be cl ose to the fb.

board. If there is a difference between them, then answer for both.

3-4m ohms. with lvds unplugged 400k one side other 300k ohms.. TV on testin g pins closest to FB the highest was 1.4v - 0v..

TV on .2mv on FB TV on lvds unplgged pins closest to FB 2v- .3 mv.. hope i covered everything...

Reply to
Stu jaxon

it is disconnected from the TCON. IIRC, the CN702 connector goes to the po wer supply, not the main. Is there 12V on the LVDS connector when it is li fted off the TCON?

ed on ohms scale and with the tv on I get OL with the backlights on, when t he backlights go out the fb reads lights a cap starts high 320k on both sid es, this is with the new board recently purchased from ebay.. and what wire am i supposed to get 12v on at lvds connector when i pull it, there's 20-3

0 wires..?

b to ground?

your meter on ohms, what is the resistance on the fb to ground?

reading at the fb?

e at the LVDS harness. But if there is no voltage at the fb, then we want to look for it with the TCON disconnected by reading it at the unplugged LV DS harness.

ral pins. The correct pins will be physically close to the fb, in other wo rds, the first couple of pins at the side of the harness that would be clos e to the fb.

oard. If there is a difference between them, then answer for both.

hms. with lvds unplugged 400k one side other 300k ohms.. TV on testing pins closest to FB the highest was 1.4v - 0v..

2mv on FB TV lvds unplgged pins closest to FB 2v- .3 mv.. hope i covered e verything...

Standby till Monday. I have a donor set of boards for that model but it's for the version with a separate TCON and FRC, so I don't have the combo TCO N that you do. Still, the voltages from the main should be the same on the LVDS harness. I'll put the boards together and get some voltage readings.

Reply to
John-Del

n it is disconnected from the TCON. IIRC, the CN702 connector goes to the power supply, not the main. Is there 12V on the LVDS connector when it is lifted off the TCON?

ured on ohms scale and with the tv on I get OL with the backlights on, when the backlights go out the fb reads lights a cap starts high 320k on both s ides, this is with the new board recently purchased from ebay.. and what wi re am i supposed to get 12v on at lvds connector when i pull it, there's 20

-30 wires..?

fb to ground?

d your meter on ohms, what is the resistance on the fb to ground?

ou reading at the fb?

age at the LVDS harness. But if there is no voltage at the fb, then we wan t to look for it with the TCON disconnected by reading it at the unplugged LVDS harness.

veral pins. The correct pins will be physically close to the fb, in other words, the first couple of pins at the side of the harness that would be cl ose to the fb.

board. If there is a difference between them, then answer for both.

ohms. with lvds unplugged 400k one side other 300k ohms.. TV on testing pi ns closest to FB the highest was 1.4v - 0v..

.2mv on FB TV lvds unplgged pins closest to FB 2v- .3 mv.. hope i covered everything...

s for the version with a separate TCON and FRC, so I don't have the combo T CON that you do. Still, the voltages from the main should be the same on th e LVDS harness. I'll put the boards together and get some voltage readings .

I found both fuses on the main boards are open f701,.. circled in yellow, t he fuses are next to cn701 harness from the power supply.

formatting link
/a/yf8cz7v

Reply to
Stu jaxon

on .2mv on FB TV lvds unplgged pins closest to FB 2v- .3 mv.. hope i cover ed everything...

t's for the version with a separate TCON and FRC, so I don't have the combo TCON that you do. Still, the voltages from the main should be the same on the LVDS harness. I'll put the boards together and get some voltage readin gs.

the fuses are next to cn701 harness from the power supply. https://imgur.c om/a/yf8cz7v

Stan, you have two original boards and two replacement boards. It's import ant to identify if any particular voltage or resistance is on the original, the replacement, or both!

I have a main for a similar model that I was able to power up. With the TV ON, at fuse F701 there should be 12V on both sides of the fuse if the fus e is good.. F702 should have 24V, same conditions.

Near the LVDS output harness on the main is a ferrite bead smd FB416. Ther e should be 12V on that.

With the TV powered down, the main disconnected from the TV, and enough tim e gone by to make sure voltage is bled off the main, there should be a resi stance of no less than several thousand ohms.

If those resistances are OK, plug the main back into the TCON. If the resi stance drops anywhere to the tens of ohms or lower, the TCON is bad.

Make sure you runs these tests on all boards in every combination.

Reply to
str00ntz

V on .2mv on FB TV lvds unplgged pins closest to FB 2v- .3 mv.. hope i cov ered everything...

it's for the version with a separate TCON and FRC, so I don't have the com bo TCON that you do. Still, the voltages from the main should be the same o n the LVDS harness. I'll put the boards together and get some voltage read ings.

w, the fuses are next to cn701 harness from the power supply. https://imgur .com/a/yf8cz7v

rtant to identify if any particular voltage or resistance is on the origina l, the replacement, or both!

TV ON, at fuse F701 there should be 12V on both sides of the fuse if the f use is good.. F702 should have 24V, same conditions.

ere should be 12V on that.

ime gone by to make sure voltage is bled off the main, there should be a re sistance of no less than several thousand ohms.

sistance drops anywhere to the tens of ohms or lower, the TCON is bad.

I changed the fuse f701 on the main board before you posted. I installed th e original tcon board, and powered on the tv, and got no pic, no audio, and the backlights went on and then off, no blown fuse. so, i installed the ne w tcon board recently purchased from ebay, and the fuse f701 blew. I should have removed the ribbon cables, I tested some caps on the original and fou nd that three metal cylindrical caps are shorted. I know it makes no sense. but anyways, I returned the new board back to ebay, and am going to purcha se a new one. I want to make the tests you mentioned but am out of fuses, s o how i can i find the ratings on them, it's a smd white fuse with a number 5 on it, any ideas..?

Reply to
Stu jaxon

I don't know if it works on all of them today, but if you take your fingers and bounce them kinda hard and you see glimpses of light the backlight is working. You might be missing power to the Tcon or have a bad Tcon. Unfortu nately I do not recommend putting any money into this new junk.

Best course of action now is to always save the box and get he longest FACT ORY warranty they have after you buy a new one.

Only other thing is to look for bad caps. Either the bulge or not but I got other ways of testing them.

Reply to
Jeff Urban

rs and bounce them kinda hard and you see glimpses of light the backlight i s working. You might be missing power to the Tcon or have a bad Tcon. Unfor tunately I do not recommend putting any money into this new junk.

CTORY warranty they have after you buy a new one.

ot other ways of testing them.

I did bounce the ribbon cables around, no flicker, than again the main boar d fuse f701 is blown, no 12v on either side fb401. how do i find the fuse r atings for the main board, and you said you have other ways of testing the caps on the tcon..?

Reply to
Stu jaxon

the original tcon board, and powered on the tv, and got no pic, no audio, a nd the backlights went on and then off, no blown fuse. so, i installed the new tcon board recently purchased from ebay, and the fuse f701 blew. I shou ld have removed the ribbon cables, I tested some caps on the original and f ound that three metal cylindrical caps are shorted. I know it makes no sens e. but anyways, I returned the new board back to ebay, and am going to purc hase a new one. I want to make the tests you mentioned but am out of fuses, so how i can i find the ratings on them, it's a smd white fuse with a numb er 5 on it, any ideas..?

The two fuses on the main are marked with a T. According to my notes, that makes them 5A 32V.

Again, you're not differentiating what boards are what.

Did you blow fuses on both mains?

One more time: replace the fuses on one of the mains and install the compl ete set of boards. Do not turn the TV on. Read the resistance of the fuse s on the main and FB416 near the LVDS connector on the main to ground.

They should have no less than several thousand ohms on any of those points. If you get a low reading, disconnect the TCON. If the short goes away, y our TCON is shorted. Install you second TCON and read again. If the short reappears, your second TCON is shorted.

If you get a low ohm condition to ground on the fuses or the FB, you'll blo w fuses every time you plug it in.

Those caps are bypass filters to ground and will read short if the source t hey're on is feeding a shorted device. Those larger caps might also be byp assed by low value low ESR ceramic caps, any of which will present a short across any of the parts paralleled in the circuit.

Reply to
John-Del

d the original tcon board, and powered on the tv, and got no pic, no audio, and the backlights went on and then off, no blown fuse. so, i installed th e new tcon board recently purchased from ebay, and the fuse f701 blew. I sh ould have removed the ribbon cables, I tested some caps on the original and found that three metal cylindrical caps are shorted. I know it makes no se nse. but anyways, I returned the new board back to ebay, and am going to pu rchase a new one. I want to make the tests you mentioned but am out of fuse s, so how i can i find the ratings on them, it's a smd white fuse with a nu mber 5 on it, any ideas..?

at makes them 5A 32V.

plete set of boards. Do not turn the TV on. Read the resistance of the fu ses on the main and FB416 near the LVDS connector on the main to ground.

s. If you get a low reading, disconnect the TCON. If the short goes away, your TCON is shorted. Install you second TCON and read again. If the shor t reappears, your second TCON is shorted.

low fuses every time you plug it in.

they're on is feeding a shorted device. Those larger caps might also be b ypassed by low value low ESR ceramic caps, any of which will present a shor t across any of the parts paralleled in the circuit.

I'm outta fuses, any idea where i can find them..?, the Length is about.1/4 in, or 6.25mm. i searched and searched all I can find is the small ones.

Reply to
Stu jaxon

d the original tcon board, and powered on the tv, and got no pic, no audio, and the backlights went on and then off, no blown fuse. so, i installed th e new tcon board recently purchased from ebay, and the fuse f701 blew. I sh ould have removed the ribbon cables, I tested some caps on the original and found that three metal cylindrical caps are shorted. I know it makes no se nse. but anyways, I returned the new board back to ebay, and am going to pu rchase a new one. I want to make the tests you mentioned but am out of fuse s, so how i can i find the ratings on them, it's a smd white fuse with a nu mber 5 on it, any ideas..?

at makes them 5A 32V.

plete set of boards. Do not turn the TV on. Read the resistance of the fu ses on the main and FB416 near the LVDS connector on the main to ground.

s. If you get a low reading, disconnect the TCON. If the short goes away, your TCON is shorted. Install you second TCON and read again. If the shor t reappears, your second TCON is shorted.

low fuses every time you plug it in.

they're on is feeding a shorted device. Those larger caps might also be b ypassed by low value low ESR ceramic caps, any of which will present a shor t across any of the parts paralleled in the circuit.

oops, the length on the fuse is 2/8 or 6.25mm.

Reply to
Stu jaxon

d the original tcon board, and powered on the tv, and got no pic, no audio, and the backlights went on and then off, no blown fuse. so, i installed th e new tcon board recently purchased from ebay, and the fuse f701 blew. I sh ould have removed the ribbon cables, I tested some caps on the original and found that three metal cylindrical caps are shorted. I know it makes no se nse. but anyways, I returned the new board back to ebay, and am going to pu rchase a new one. I want to make the tests you mentioned but am out of fuse s, so how i can i find the ratings on them, it's a smd white fuse with a nu mber 5 on it, any ideas..?

at makes them 5A 32V.

plete set of boards. Do not turn the TV on. Read the resistance of the fu ses on the main and FB416 near the LVDS connector on the main to ground.

s. If you get a low reading, disconnect the TCON. If the short goes away, your TCON is shorted. Install you second TCON and read again. If the shor t reappears, your second TCON is shorted.

low fuses every time you plug it in.

they're on is feeding a shorted device. Those larger caps might also be b ypassed by low value low ESR ceramic caps, any of which will present a shor t across any of the parts paralleled in the circuit.

I tested FB416 near the lvds cable both sides to ground on the main board, a short on both sides, .6 ohms. removed the lvds cable from the Tcon board short went away. is there anyway to test the panel for a short.?

Reply to
Stu jaxon

led the original tcon board, and powered on the tv, and got no pic, no audi o, and the backlights went on and then off, no blown fuse. so, i installed the new tcon board recently purchased from ebay, and the fuse f701 blew. I should have removed the ribbon cables, I tested some caps on the original a nd found that three metal cylindrical caps are shorted. I know it makes no sense. but anyways, I returned the new board back to ebay, and am going to purchase a new one. I want to make the tests you mentioned but am out of fu ses, so how i can i find the ratings on them, it's a smd white fuse with a number 5 on it, any ideas..?

that makes them 5A 32V.

omplete set of boards. Do not turn the TV on. Read the resistance of the fuses on the main and FB416 near the LVDS connector on the main to ground.

nts. If you get a low reading, disconnect the TCON. If the short goes awa y, your TCON is shorted. Install you second TCON and read again. If the sh ort reappears, your second TCON is shorted.

blow fuses every time you plug it in.

ce they're on is feeding a shorted device. Those larger caps might also be bypassed by low value low ESR ceramic caps, any of which will present a sh ort across any of the parts paralleled in the circuit.

, a short on both sides, .6 ohms. removed the lvds cable from the Tcon boa rd short went away. is there anyway to test the panel for a short.?

It's unlikely the panel is causing the problem. The only TV I know of that would blow the TCON because of a shorted display is the Vizio E701i-A3.

You need to acquire another TCON, and *before* you power the TV up, measure the resistances of the fuses and ferrite bead to ground with all the board s connected. If you pick up the short, you bought another bad TCON.

If there are no shorts at this point, power up the TV with the two ribbons disconnected from the display. If the backlights stay on and the TV runs f or 10 minutes or so, unplug the TV and reconnect the ribbons to the display and try again. If the TCON shorts with the ribbons reconnected, then you have a bad display taking out the TCON. I would suspect Windex Syndrome (cl eaning solution sprayed on the screen in such a volume that it drips below the front mask and attacks the bonded address boards).

Reply to
John-Del

alled the original tcon board, and powered on the tv, and got no pic, no au dio, and the backlights went on and then off, no blown fuse. so, i installe d the new tcon board recently purchased from ebay, and the fuse f701 blew. I should have removed the ribbon cables, I tested some caps on the original and found that three metal cylindrical caps are shorted. I know it makes n o sense. but anyways, I returned the new board back to ebay, and am going t o purchase a new one. I want to make the tests you mentioned but am out of fuses, so how i can i find the ratings on them, it's a smd white fuse with a number 5 on it, any ideas..?

, that makes them 5A 32V.

complete set of boards. Do not turn the TV on. Read the resistance of th e fuses on the main and FB416 near the LVDS connector on the main to ground .

oints. If you get a low reading, disconnect the TCON. If the short goes a way, your TCON is shorted. Install you second TCON and read again. If the short reappears, your second TCON is shorted.

ll blow fuses every time you plug it in.

urce they're on is feeding a shorted device. Those larger caps might also be bypassed by low value low ESR ceramic caps, any of which will present a short across any of the parts paralleled in the circuit.

rd, a short on both sides, .6 ohms. removed the lvds cable from the Tcon b oard short went away. is there anyway to test the panel for a short.?

t would blow the TCON because of a shorted display is the Vizio E701i-A3.

re the resistances of the fuses and ferrite bead to ground with all the boa rds connected. If you pick up the short, you bought another bad TCON.

s disconnected from the display. If the backlights stay on and the TV runs for 10 minutes or so, unplug the TV and reconnect the ribbons to the displ ay and try again. If the TCON shorts with the ribbons reconnected, then yo u have a bad display taking out the TCON. I would suspect Windex Syndrome ( cleaning solution sprayed on the screen in such a volume that it drips belo w the front mask and attacks the bonded address boards).

OK, Thanks for all your help. now I have to order a new tcon board and fuse s. and there are no tcon boards available for this tv that i found.

Reply to
Stu jaxon

stalled the original tcon board, and powered on the tv, and got no pic, no audio, and the backlights went on and then off, no blown fuse. so, i instal led the new tcon board recently purchased from ebay, and the fuse f701 blew . I should have removed the ribbon cables, I tested some caps on the origin al and found that three metal cylindrical caps are shorted. I know it makes no sense. but anyways, I returned the new board back to ebay, and am going to purchase a new one. I want to make the tests you mentioned but am out o f fuses, so how i can i find the ratings on them, it's a smd white fuse wit h a number 5 on it, any ideas..?

es, that makes them 5A 32V.

he complete set of boards. Do not turn the TV on. Read the resistance of the fuses on the main and FB416 near the LVDS connector on the main to grou nd.

points. If you get a low reading, disconnect the TCON. If the short goes away, your TCON is shorted. Install you second TCON and read again. If th e short reappears, your second TCON is shorted.

u'll blow fuses every time you plug it in.

source they're on is feeding a shorted device. Those larger caps might als o be bypassed by low value low ESR ceramic caps, any of which will present a short across any of the parts paralleled in the circuit.

oard, a short on both sides, .6 ohms. removed the lvds cable from the Tcon board short went away. is there anyway to test the panel for a short.?

hat would blow the TCON because of a shorted display is the Vizio E701i-A3.

sure the resistances of the fuses and ferrite bead to ground with all the b oards connected. If you pick up the short, you bought another bad TCON.

ons disconnected from the display. If the back-lights stay on and the TV r uns for 10 minutes or so, unplug the TV and reconnect the ribbons to the di splay and try again. If the TCON shorts with the ribbons reconnected, then you have a bad display taking out the TCON. I would suspect Windex Syndrom e (cleaning solution sprayed on the screen in such a volume that it drips b elow the front mask and attacks the bonded address boards).

ses. and there are no tcon boards available for this tv that i found.

I installed the new tcon board along with the fuse on the main board,I took measurements, no shorts. with the ribbons disconnected, I powered up the t v, back-lights stayed on a little longer, but went out... I took measuremen ts again still no shorts..

Reply to
Stu jaxon

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