RCA main board

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Hi Group, need help choosing a main board for an RCA TV model .. led32c45rq.. main board # fre01m3393lna35-a2.. i want to know if this board ..42RE01M3393LNA35-A2 Main Board for LED42C45RQ  will work in replace of the one mentioned ???  

Re: RCA main board
:
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rq.. main board # fre01m3393lna35-a2.. i want to know if this board ..42RE0
1M3393LNA35-A2 Main Board for LED42C45RQ will work in replace of the one me
ntioned ???

The only way is to try it.  There are two potential problems of high probab
ility:  the keyboard switches may not work as assigned, and you may have no
 picture, a badly pixelated picture, or an upside down picture because thes
e boards don't drive the same screen.   If the board is close enough, swapp
ing the eeprom from the original board will usually fix the picture issues  
and likely the keyboard issues, but that's assuming the original eeprom is  
good.  Since the eeprom is the most likely cause of any non-lightning failu
res of these boards, you may be moving a bad eeprom into a good board.

I've done that type of swap when I had a board in stock as it only takes a  
few minutes to try it, but wouldn't order a board for the attempt.

Did you confirm the power supply is OK?  Getting standby 5V is not enough.  
 You can jump the stby pin to the ps on pin and see if the 12V comes up.  I
f it doesn't, the power supply is bad.  If it does, it's the main.




Re: RCA main board
On 08/12/2020 12:50, snipped-for-privacy@gmail.com wrote:
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Programmed eeproms also seem available on eBay, bit of a markup though.

It's not difficult to make a programmer, running out of a parallel port  
of an old PC. Or using an SBC such as a Raspberry-Pi.

--  
Adrian C

Re: RCA main board
On Tuesday, December 8, 2020 at 2:24:15 PM UTC-5, Adrian Caspersz wrote:
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rote:  
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c45rq.. main board # fre01m3393lna35-a2.. i want to know if this board ..42
RE01M3393LNA35-A2 Main Board for LED42C45RQ will work in replace of the one
 mentioned ???  
Quoted text here. Click to load it
bability: the keyboard switches may not work as assigned, and you may have  
no picture, a badly pixelated picture, or an upside down picture because th
ese boards don't drive the same screen. If the board is close enough, swapp
ing the eeprom from the original board will usually fix the picture issues  
and likely the keyboard issues, but that's assuming the original eeprom is  
good. Since the eeprom is the most likely cause of any non-lightning failur
es of these boards, you may be moving a bad eeprom into a good board.
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I offered to email him the .bin file but the OP doesn't have a programmer.  
 Besides, the time to have a cheap programmer for TVs is ending.  Most TVs  
made in the last couple of years are "smart" and they use memory on BGA chi
ps, not easily replaceable 25 series eeproms.




Re: RCA main board
On 12/8/20 1:24 PM, Adrian Caspersz wrote:
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Or, you could just buy the right tools to do it correctly.
<https://www.ebay.com/itm/133033993647
For $60.23


--  
"I am a river to my people."
Jeff-1.0
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Re: RCA main board
On Tuesday, December 8, 2020 at 3:54:57 PM UTC-5, Fox's Mercantile wrote:
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That's the one I've been using recently.  Works well.


Re: RCA main board
On Tuesday, December 8, 2020 at 7:50:49 AM UTC-5, snipped-for-privacy@gmail.com wrote:
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te:  
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45rq.. main board # fre01m3393lna35-a2.. i want to know if this board ..42R
E01M3393LNA35-A2 Main Board for LED42C45RQ will work in replace of the one  
mentioned ???
Quoted text here. Click to load it
bility: the keyboard switches may not work as assigned, and you may have no
 picture, a badly pixelated picture, or an upside down picture because thes
e boards don't drive the same screen. If the board is close enough, swappin
g the eeprom from the original board will usually fix the picture issues an
d likely the keyboard issues, but that's assuming the original eeprom is go
od. Since the eeprom is the most likely cause of any non-lightning failures
 of these boards, you may be moving a bad eeprom into a good board.  
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a few minutes to try it, but wouldn't order a board for the attempt.  
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 You can jump the stby pin to the ps on pin and see if the 12V comes up. If
 it doesn't, the power supply is bad. If it does, it's the main.

I'm reading a short across both sides of the fuse 3a/125v to ground, on the
 tcon board, there's short somewhere.???

Re: RCA main board
On Sunday, March 14, 2021 at 1:41:01 PM UTC-4, Stu jaxon wrote:
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rote:  
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2c45rq.. main board # fre01m3393lna35-a2.. i want to know if this board ..4
2RE01M3393LNA35-A2 Main Board for LED42C45RQ will work in replace of the on
e mentioned ???  
Quoted text here. Click to load it
bability: the keyboard switches may not work as assigned, and you may have  
no picture, a badly pixelated picture, or an upside down picture because th
ese boards don't drive the same screen. If the board is close enough, swapp
ing the eeprom from the original board will usually fix the picture issues  
and likely the keyboard issues, but that's assuming the original eeprom is  
good. Since the eeprom is the most likely cause of any non-lightning failur
es of these boards, you may be moving a bad eeprom into a good board.  
Quoted text here. Click to load it
s a few minutes to try it, but wouldn't order a board for the attempt.  
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h. You can jump the stby pin to the ps on pin and see if the 12V comes up.  
If it doesn't, the power supply is bad. If it does, it's the main.
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he tcon board, there's short somewhere.???

With the LVDS cable disconnected, you should not be getting any low resista
nce to the ground screws of the TCON.  If so, there's a short.  The most co
mmon reason for a dead short on a TCON are one of the multi layer chip capa
citors (they're surface mounted and have no markings).  While any dead shor
t is easy to find with an ohm meter, these caps are usually found in groups
 of two to ten or more all paralleled, so one shorted cap makes them all lo
ok bad.  Other than a Huntron, the easiest way to find this is to feed a li
mited current (2 amps tops) into the short with a variable supply and spray
 the board with freeze spray until the board frosts over.  The first cap to
 thaw is the shorted one.

Re: RCA main board
On Sunday, March 14, 2021 at 2:51:41 PM UTC-4, snipped-for-privacy@gmail.com wrote:
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e:  
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 wrote:  
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d32c45rq.. main board # fre01m3393lna35-a2.. i want to know if this board .
.42RE01M3393LNA35-A2 Main Board for LED42C45RQ will work in replace of the  
one mentioned ???  
Quoted text here. Click to load it
robability: the keyboard switches may not work as assigned, and you may hav
e no picture, a badly pixelated picture, or an upside down picture because  
these boards don't drive the same screen. If the board is close enough, swa
pping the eeprom from the original board will usually fix the picture issue
s and likely the keyboard issues, but that's assuming the original eeprom i
s good. Since the eeprom is the most likely cause of any non-lightning fail
ures of these boards, you may be moving a bad eeprom into a good board.  
Quoted text here. Click to load it
kes a few minutes to try it, but wouldn't order a board for the attempt.  
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ugh. You can jump the stby pin to the ps on pin and see if the 12V comes up
. If it doesn't, the power supply is bad. If it does, it's the main.  
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 the tcon board, there's short somewhere.???
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tance to the ground screws of the TCON. If so, there's a short. The most co
mmon reason for a dead short on a TCON are one of the multi layer chip capa
citors (they're surface mounted and have no markings). While any dead short
 is easy to find with an ohm meter, these caps are usually found in groups  
of two to ten or more all paralleled, so one shorted cap makes them all loo
k bad. Other than a Huntron, the easiest way to find this is to feed a limi
ted current (2 amps tops) into the short with a variable supply and spray t
he board with freeze spray until the board frosts over. The first cap to th
aw is the shorted one.

Extremely clever, and useful.  Will have to file this trick away.  
I usually do hunting by keeping the board powered up for a bit then spray t
argeted components.  
Thanks
J

Re: RCA main board
On Monday, March 15, 2021 at 2:13:19 PM UTC-4, three_jeeps wrote:
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ote:  
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om wrote:  
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led32c45rq.. main board # fre01m3393lna35-a2.. i want to know if this board
 ..42RE01M3393LNA35-A2 Main Board for LED42C45RQ will work in replace of th
e one mentioned ???  
Quoted text here. Click to load it
 probability: the keyboard switches may not work as assigned, and you may h
ave no picture, a badly pixelated picture, or an upside down picture becaus
e these boards don't drive the same screen. If the board is close enough, s
wapping the eeprom from the original board will usually fix the picture iss
ues and likely the keyboard issues, but that's assuming the original eeprom
 is good. Since the eeprom is the most likely cause of any non-lightning fa
ilures of these boards, you may be moving a bad eeprom into a good board.
  
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takes a few minutes to try it, but wouldn't order a board for the attempt.
  
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nough. You can jump the stby pin to the ps on pin and see if the 12V comes  
up. If it doesn't, the power supply is bad. If it does, it's the main.  
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on the tcon board, there's short somewhere.???  
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istance to the ground screws of the TCON. If so, there's a short. The most  
common reason for a dead short on a TCON are one of the multi layer chip ca
pacitors (they're surface mounted and have no markings). While any dead sho
rt is easy to find with an ohm meter, these caps are usually found in group
s of two to ten or more all paralleled, so one shorted cap makes them all l
ook bad. Other than a Huntron, the easiest way to find this is to feed a li
mited current (2 amps tops) into the short with a variable supply and spray
 the board with freeze spray until the board frosts over. The first cap to  
thaw is the shorted one.
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 targeted components.  
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That works if the supply maintains the struggle of feeding the short, but m
ost of these more recent circuits (like these TCONs) are fed by buck conver
ters who shutdown when the programmed current value is reached, so the offe
nding load part never gets hot.  When using the forced current trick, one m
ust remember to limit the voltage, as sometimes the shorted part may sudden
ly open under the strain and an over-voltage will then damage something els
e.  


Re: RCA main board
On Monday, March 15, 2021 at 7:07:02 PM UTC-4, snipped-for-privacy@gmail.com wrote:
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wrote:  
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.com wrote:  
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. led32c45rq.. main board # fre01m3393lna35-a2.. i want to know if this boa
rd ..42RE01M3393LNA35-A2 Main Board for LED42C45RQ will work in replace of  
the one mentioned ???  
Quoted text here. Click to load it
gh probability: the keyboard switches may not work as assigned, and you may
 have no picture, a badly pixelated picture, or an upside down picture beca
use these boards don't drive the same screen. If the board is close enough,
 swapping the eeprom from the original board will usually fix the picture i
ssues and likely the keyboard issues, but that's assuming the original eepr
om is good. Since the eeprom is the most likely cause of any non-lightning  
failures of these boards, you may be moving a bad eeprom into a good board.
  
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y takes a few minutes to try it, but wouldn't order a board for the attempt
.  
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 enough. You can jump the stby pin to the ps on pin and see if the 12V come
s up. If it doesn't, the power supply is bad. If it does, it's the main.  
Quoted text here. Click to load it
, on the tcon board, there's short somewhere.???  
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esistance to the ground screws of the TCON. If so, there's a short. The mos
t common reason for a dead short on a TCON are one of the multi layer chip  
capacitors (they're surface mounted and have no markings). While any dead s
hort is easy to find with an ohm meter, these caps are usually found in gro
ups of two to ten or more all paralleled, so one shorted cap makes them all
 look bad. Other than a Huntron, the easiest way to find this is to feed a  
limited current (2 amps tops) into the short with a variable supply and spr
ay the board with freeze spray until the board frosts over. The first cap t
o thaw is the shorted one.  
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ay targeted components.  
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 most of these more recent circuits (like these TCONs) are fed by buck conv
erters who shutdown when the programmed current value is reached, so the of
fending load part never gets hot. When using the forced current trick, one  
must remember to limit the voltage, as sometimes the shorted part may sudde
nly open under the strain and an over-voltage will then damage something el
se.


I have a variable ps, and medical freeze spray, but i never injected a volt
age/current into a circuit. could use some tips/pointers.??

Re: RCA main board
On Tuesday, March 16, 2021 at 7:25:57 PM UTC-4, Stu jaxon wrote:

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nd, on the tcon board, there's short somewhere.???  
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 resistance to the ground screws of the TCON. If so, there's a short. The m
ost common reason for a dead short on a TCON are one of the multi layer chi
p capacitors (they're surface mounted and have no markings). While any dead
 short is easy to find with an ohm meter, these caps are usually found in g
roups of two to ten or more all paralleled, so one shorted cap makes them a
ll look bad. Other than a Huntron, the easiest way to find this is to feed  
a limited current (2 amps tops) into the short with a variable supply and s
pray the board with freeze spray until the board frosts over. The first cap
 to thaw is the shorted one.  
Quoted text here. Click to load it
pray targeted components.  
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ut most of these more recent circuits (like these TCONs) are fed by buck co
nverters who shutdown when the programmed current value is reached, so the  
offending load part never gets hot. When using the forced current trick, on
e must remember to limit the voltage, as sometimes the shorted part may sud
denly open under the strain and an over-voltage will then damage something  
else.
Quoted text here. Click to load it
ltage/current into a circuit. could use some tips/pointers.??

Re: RCA main board
On Tuesday, March 16, 2021 at 7:25:57 PM UTC-4, Stu jaxon wrote:
  
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nd, on the tcon board, there's short somewhere.???  
Quoted text here. Click to load it
 resistance to the ground screws of the TCON. If so, there's a short. The m
ost common reason for a dead short on a TCON are one of the multi layer chi
p capacitors (they're surface mounted and have no markings). While any dead
 short is easy to find with an ohm meter, these caps are usually found in g
roups of two to ten or more all paralleled, so one shorted cap makes them a
ll look bad. Other than a Huntron, the easiest way to find this is to feed  
a limited current (2 amps tops) into the short with a variable supply and s
pray the board with freeze spray until the board frosts over. The first cap
 to thaw is the shorted one.  
Quoted text here. Click to load it
pray targeted components.  
Quoted text here. Click to load it
ut most of these more recent circuits (like these TCONs) are fed by buck co
nverters who shutdown when the programmed current value is reached, so the  
offending load part never gets hot. When using the forced current trick, on
e must remember to limit the voltage, as sometimes the shorted part may sud
denly open under the strain and an over-voltage will then damage something  
else.
Quoted text here. Click to load it
ltage/current into a circuit. could use some tips/pointers.??

Simply feed 2 amps (but no more) on either side of the fuse with respect to
 ground (the screw lands are fine).  Since the input to the TCON is 12V, ma
ke sure your supply does't go over 10V or so.  With a dead short, you shoul
d be reading mostly current and almost no voltage.  Spray the whole board w
ith freeze spray so it frosts over.  Watch what thaws first.  Could be one  
of the brown chip caps or even one of the chips.

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