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ote:
-Del wrote:
4, Stu jax> > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > hi group, i'm working on a Vizio 39 Tesla 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..?