RCA main board

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 ???

Reply to
Hilda Winkler
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On Monday, December 7, 2020 at 9:03:09 PM UTC-5, snipped-for-privacy@gmail.com wrote :

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.

Reply to
ohger1s

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.

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Adrian C
Reply to
Adrian Caspersz

rote:

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 ???

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.

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.

Reply to
ohger1s

Or, you could just buy the right tools to do it correctly. For $60.23

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"I am a river to my people." 
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Reply to
Fox's Mercantile

That's the one I've been using recently. Works well.

Reply to
ohger1s

te:

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 ???

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.

a few minutes to try it, but wouldn't order a board for the attempt.

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.???

Reply to
Stu jaxon

rote:

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 ???

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.

s a few minutes to try it, but wouldn't order a board for the attempt.

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.

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.

Reply to
ohger1s

e:

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 ???

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.

kes a few minutes to try it, but wouldn't order a board for the attempt.

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.

the tcon board, there's short somewhere.???

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

Reply to
three_jeeps

ote:

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 ???

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.

takes a few minutes to try it, but wouldn't order a board for the attempt.

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.

on the tcon board, there's short somewhere.???

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.

targeted components.

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.

Reply to
ohger1s

. 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 ???

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.

y takes a few minutes to try it, but wouldn't order a board for the attempt .

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.

, on the tcon board, there's short somewhere.???

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.

ay targeted components.

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.??

Reply to
Stu jaxon

nd, on the tcon board, there's short somewhere.???

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.

pray targeted components.

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.

ltage/current into a circuit. could use some tips/pointers.??

Reply to
ohger1s

nd, on the tcon board, there's short somewhere.???

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.

pray targeted components.

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.

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.

Reply to
ohger1s

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