TH-P50G15A - 6 Blinks- Bad TNPA4782

[tom66]

Re: TH-P50G15A - 6 Blinks- Bad TNPA4782

Which buffer ICs failed? tried removing a few failed ones and see if it will fire up with a pic?

[tw2005]

Re: TH-P50G15A - 6 Blinks- Bad TNPA4782

Which buffer ICs failed? tried removing a few failed ones and see if it will fire up with a pic?

Don't have the gear. brought everything except the kitchen sink and the acetone

Not worth the

All connectors on the SD. 8 ICs on these too.

[Glitcher]

Re: TH-P50G15A - 6 Blinks- Bad TNPA4782

I thought I also had this but nope. Found two resistors R521 and R522 open circuit near IC521. I initially had IC521 shorted which was replaced. replaced the resistors but still getting a short flash and then 6 blinks.

[tw2005]

Re: TH-P50G15A - 6 Blinks- Bad TNPA4782

I thought I also had this but nope. Found two resistors R521 and R522 open circuit near IC521. I initially had IC521 shorted which was replaced. replaced the resistors but still getting a short flash and then 6 blinks.

Can you put a summary list of what you've replaced?

Did you check those 2 diodes (marked 88) that I just had shorted ?

[tw2005]

Re: TH-P50G15A - 6 Blinks- Bad TNPA4782

Buffers are in. (thanks for Overnight express) Perfect,Perfect Perfect. Fantastic image and SC is now silent with a load .

10500 Hrs

Now have another TNPA4782 to repair. A lot learnt here as far as what parts you can get away with , with some lateral thinking and cross relating knowledge of the 5081 boards.

[Glitcher]

Re: TH-P50G15A - 6 Blinks- Bad TNPA4782

Everything I found shorted so far:

Q441 - 45G127 replaced with a 45G128
IC521 - replaced with the 1737
Q551
Q661 - RJP6065 replaced with RJP63F3
Q601 - RJP6026
Q701
Q702
IC773

D608
D618
R521
R522

I also checked all the parts that you had shorted or suspect and none seemed shorted, but I replaced some of them just in case.

[tw2005]

Re: TH-P50G15A - 6 Blinks- Bad TNPA4782

Just having a look at this spare dead 4782AF, straight away I see D618 is burnt. I'm starting to think i missed this as it's in the shadows of the heatsink .

What's unusual is this too being revision AF , however it has a Vset cct.n So i have one which has and another not both AF. This board does look a little older so maybe mine was the last of a production change. Both TVs are P50G15A

[Glitcher]

Re: TH-P50G15A - 6 Blinks- Bad TNPA4782

Mine is the AB model, I got from a TCP50S1. I did the initial replacing parts and heard a pop and burnt smell which turned out to be D618, and also leading to D608 blowing ,Realizing I missed IC521 and Q551. after replacing everything again, 7 blinks turned to 6 blinks.

If the SC is repaired and with SC50 jumpered and SC plugged in, the set should stay on solid and no blinks correct?

[tw2005]

Re: TH-P50G15A - 6 Blinks- Bad TNPA4782

Everything I found shorted so far:

Q441 - 45G127 replaced with a 45G128
IC521 - replaced with the 1737
Q551
Q661 - RJP6065 replaced with RJP63F3
Q601 - RJP6026
Q701
Q702
IC773

D608
D618
R521
R522

I also checked all the parts that you had shorted or suspect and none seemed shorted, but I replaced some of them just in case.

Does not seem quite fair does it.

I don't see and 2sk3018 or 78L05 regs replaced

have you tripled checked all smd diodes(large ones) and if 45G127 failed is the didoe in front of that ok and the 2 TO220 diode packs next to it?

[tw2005]

Re: TH-P50G15A - 6 Blinks- Bad TNPA4782

Mine is the AB model, I got from a TCP50S1. I did the initial replacing parts and heard a pop and burnt smell which turned out to be D618, and also leading to D608 blowing ,Realizing I missed IC521 and Q551. after replacing everything again, 7 blinks turned to 6 blinks.

If the SC is repaired and with SC50 jumpered and SC plugged in, the set should stay on solid and no blinks correct?

yep and i strongly recommend you test it that way until it does becasue I'm convinced I killed my buffer boards.

[tw2005]

Re: TH-P50G15A - 6 Blinks- Bad TNPA4782

Have you rechecked the buffers yet? I'd check Vfo at the connector to Vfg resistance

[Glitcher]

Re: TH-P50G15A - 6 Blinks- Bad TNPA4782

So far I also replaced Q818 2sk3018 and only IC771 78L05, IC724 and IC725 seem good. I checked about every large smd diode I can find and nothing seem shorted. Q441 was 45G127 (the one on the right heatsink). that one didn't have a diode in front of it. measuring the TO-220 diodes I'm getting 0.287 and OL.

[tw2005]

Re: TH-P50G15A - 6 Blinks- Bad TNPA4782

Ok, well i'm only just starting on this but is your Q451 shorted G-E ? I'm finding you have to be 100% thorough nearly skipped over that one.

For transistors so far, Q661,601,441,451,D618,

Also, can you look at R869, R613 47K near D618. 613 is burnt and I can't get a stable reading suggesting these may have an issue but have not looked at the schematic yet

[tw2005]

Re: TH-P50G15A - 6 Blinks- Bad TNPA4782

So far I also replaced Q818 2sk3018 and only IC771 78L05, IC724 and IC725 seem good. I checked about every large smd diode I can find and nothing seem shorted. Q441 was 45G127 (the one on the right heatsink). that one didn't have a diode in front of it. measuring the TO-220 diodes I'm getting 0.287 and OL.

yep got mixed up with other 45g127, both mine are dead

[Glitcher]

Re: TH-P50G15A - 6 Blinks- Bad TNPA4782

my Q451 measures 0.674 and OL on G-E on diode mode. both my R869 and R613 slowly raises in resistance until around 42.8k ohms.

[tw2005]

Re: TH-P50G15A - 6 Blinks- Bad TNPA4782

Q701,702,818 no shorts but I'm replacing .

I'm getting similar on those resistors. I may remove from cct and check since 1 is burnt at the solder.

Well with mine at this stage I'm thinking

Q601,661,441,451, 701,702,818,551
D618,
IC771,773,464,465(all of the Vcc lines are tied so I do not trust these inverters)
IC521

[tw2005]

Re: TH-P50G15A - 6 Blinks- Bad TNPA4782

Pins 3-5 resistance on any of these IC773,464,465. What resistance do you have?

[tw2005]

Re: TH-P50G15A - 6 Blinks- Bad TNPA4782

With that zener D608 what do you get in diode mode both directions and what resistance both directions?

[Glitcher]

Re: TH-P50G15A - 6 Blinks- Bad TNPA4782

Forgot to mention I also replaced IC773, 464, and 465 to be safe. For D806 i have 0.758 and OL in diode mode, 9.75k resistance in both directions

[tw2005]

Re: TH-P50G15A - 6 Blinks- Bad TNPA4782

Forgot to mention I also replaced IC773, 464, and 465 to be safe. For D806 i have 0.758 and OL in diode mode, 9.75k resistance in both directions

interesting, I may have an issue there. i get the resistance but in diode 1.69 and 1.67. Do you remember waht yours was reading before you replaced it?