This will be my last TV for quite a while but it's a TH-P42X20A, which would be similar to other P42X20, and P42C2 HD models. 2010 is the year of construction.
It uses the SN TNPA5066, SS TNPA5072, A-board for our market TNPH0840 MA.
I've been chipping away at this for about 6 weeks, mainly because of bad parts and a mixed up A-board order and quite frankly gave up last night with it dead and tried one last thing today and kind of running so some hope there.
Initial state of TV was straight up SOS4, been here before so expecting shorted Vsus. Confirmed, 4 shorted smd IGBTs RJP30E2.
Replaced those with IRG7S313UPBF which are only 330V 40A although FGD4536, 360 V PDP Trench IGBT would have been closer.
Short cleared, powerup now SOS1, great! Looks like A-board. Fiddle with it , reseat ribbons etc, after some power cycles, Now SOS10
5V line now shorted, the 2 buffer ICs on the A board which feed to A20 then Sn20 shorted on Vcc. replace them back to SOS1, few more fiddles and again SOS10, same deal shorted ICs. At this stage, quitting on the A-board.
Order a NZ version which the plan is to swap over all the EEPROMs to create my origanal board. Should work, the board is a 50" but apart from the data on those chips, the baord is electrically the same.(In theory)
Get the board, hook up and powerup, nil display, SN/SS both on and buzzing??
Now although it's a 50" board I should get a display. Was real lazy and just rested the A-board for testing and it slipped, swinging on the ribbons a bit, panic and check the front. It's off and SOS6(I think).
Cables do not appear to be broken although a little creasing. Nothin gets it going again.
remove the Sn board, 1 of the IGBTs on the MID energy recovery cct from the SS has shorted but everything else seems ok? It was Q441 DG501 (Panasonic IGBT) which I replaced with a DG502 left over from my SC rebuilds.
TV would not get going again but then randomly it would powerup and then I noticed there was maldicharge on 50% of the screen, C2 board side only, other half totally black.
Never seen anything like this, thinking bad C boards or a panel which was cactus.
More fiddling, no change but very erratic and SOS8. I tried following both the 2009 plasma guide which has a similar cct setup except SC/SD/SU and the P42S2 guides for isolation and blink code changes.
Ended up a real head bash because everthing was suggesting a bad A board because of the blinks . Basically if everything was hooked up I was getting a consistent SOS6(started SOS8). Disconnect SN20, still SOS6, earthed out the SOS6 line, still same.
Start with the SS and same deal SS23 undone, still SOS8, earthed out, same. Starting to look like A but SOS8 feeds through the C boards and also the sustain control to the SS so I have C on my mind although doubtful.
Then in the back of my mind I think back to the original A and the 5V being shorted which made no sense how an A board would do that except if there was something shorting?
The Ribbons, turn them over which I now look closely at for the first time, corrosion and pitting! So I grab an eraser and attempt to clean them up, somehow must of lifted one on the contacts on the SN20 ribbon and that's stuffed it. So I cut it back and not expecting it to work.
I also noted that depending on how bad that A20 ribbon was seated will produce either SOS6 or 8.
It's dead again, replaced the C541 octal buffer IC on SS board that goes to the C board just n case, no change.
Then check the cct and thinking C2 board, no shorts or burns. Suspect there's a chance the VHCT541 buffer IC could be injured, compare Vcc - gnd 8M? On another model C board, 2-3M Ohm. 8M is lookig like open cct potentially.
So do a transplant, and now reads 2-3M. Hook it all up and a fiddle and get SN & SS to stay on and now purple jaggged maldischarge on entire panel which is in fact an improvement on previous half panel.
More fiddling with the ribbons especially A20 and get and actual setup picture but with multi-coloured lines at about the last C2 board panel connection . More adjustment of that ribbon at the A board, 2 banks of line , then 1 , then none.
Great, but the picture is not. looks ok but dim and depending on what's on the panel, very similar to bad SS but i am thinking I need new ribbons definitely before I can decide if my SS or SN has issues.
If I get this sorted I'll proceed with the eeprom swaps.
Some voltages, Vs 192V, Vda 55V,
voltage on the MID ER cct SN3-SS3 95-97V
Won't be updating again for a couple of months as I'll be interstate.
Pictures at night so a little poor. Analogue TV channel as that is the only thing the same as NZ and AU, digital has different band width.
It uses the SN TNPA5066, SS TNPA5072, A-board for our market TNPH0840 MA.
I've been chipping away at this for about 6 weeks, mainly because of bad parts and a mixed up A-board order and quite frankly gave up last night with it dead and tried one last thing today and kind of running so some hope there.
Initial state of TV was straight up SOS4, been here before so expecting shorted Vsus. Confirmed, 4 shorted smd IGBTs RJP30E2.
Replaced those with IRG7S313UPBF which are only 330V 40A although FGD4536, 360 V PDP Trench IGBT would have been closer.
Short cleared, powerup now SOS1, great! Looks like A-board. Fiddle with it , reseat ribbons etc, after some power cycles, Now SOS10
5V line now shorted, the 2 buffer ICs on the A board which feed to A20 then Sn20 shorted on Vcc. replace them back to SOS1, few more fiddles and again SOS10, same deal shorted ICs. At this stage, quitting on the A-board.
Order a NZ version which the plan is to swap over all the EEPROMs to create my origanal board. Should work, the board is a 50" but apart from the data on those chips, the baord is electrically the same.(In theory)
Get the board, hook up and powerup, nil display, SN/SS both on and buzzing??
Now although it's a 50" board I should get a display. Was real lazy and just rested the A-board for testing and it slipped, swinging on the ribbons a bit, panic and check the front. It's off and SOS6(I think).
Cables do not appear to be broken although a little creasing. Nothin gets it going again.
remove the Sn board, 1 of the IGBTs on the MID energy recovery cct from the SS has shorted but everything else seems ok? It was Q441 DG501 (Panasonic IGBT) which I replaced with a DG502 left over from my SC rebuilds.
TV would not get going again but then randomly it would powerup and then I noticed there was maldicharge on 50% of the screen, C2 board side only, other half totally black.
Never seen anything like this, thinking bad C boards or a panel which was cactus.
More fiddling, no change but very erratic and SOS8. I tried following both the 2009 plasma guide which has a similar cct setup except SC/SD/SU and the P42S2 guides for isolation and blink code changes.
Ended up a real head bash because everthing was suggesting a bad A board because of the blinks . Basically if everything was hooked up I was getting a consistent SOS6(started SOS8). Disconnect SN20, still SOS6, earthed out the SOS6 line, still same.
Start with the SS and same deal SS23 undone, still SOS8, earthed out, same. Starting to look like A but SOS8 feeds through the C boards and also the sustain control to the SS so I have C on my mind although doubtful.
Then in the back of my mind I think back to the original A and the 5V being shorted which made no sense how an A board would do that except if there was something shorting?
The Ribbons, turn them over which I now look closely at for the first time, corrosion and pitting! So I grab an eraser and attempt to clean them up, somehow must of lifted one on the contacts on the SN20 ribbon and that's stuffed it. So I cut it back and not expecting it to work.
I also noted that depending on how bad that A20 ribbon was seated will produce either SOS6 or 8.
It's dead again, replaced the C541 octal buffer IC on SS board that goes to the C board just n case, no change.
Then check the cct and thinking C2 board, no shorts or burns. Suspect there's a chance the VHCT541 buffer IC could be injured, compare Vcc - gnd 8M? On another model C board, 2-3M Ohm. 8M is lookig like open cct potentially.
So do a transplant, and now reads 2-3M. Hook it all up and a fiddle and get SN & SS to stay on and now purple jaggged maldischarge on entire panel which is in fact an improvement on previous half panel.
More fiddling with the ribbons especially A20 and get and actual setup picture but with multi-coloured lines at about the last C2 board panel connection . More adjustment of that ribbon at the A board, 2 banks of line , then 1 , then none.
Great, but the picture is not. looks ok but dim and depending on what's on the panel, very similar to bad SS but i am thinking I need new ribbons definitely before I can decide if my SS or SN has issues.If I get this sorted I'll proceed with the eeprom swaps.
Some voltages, Vs 192V, Vda 55V,
voltage on the MID ER cct SN3-SS3 95-97V
Won't be updating again for a couple of months as I'll be interstate.
Pictures at night so a little poor. Analogue TV channel as that is the only thing the same as NZ and AU, digital has different band width.
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