TH-P50G15A - 6 Blinks- Bad TNPA4782

[Nick's Tvs]

Re: TH-P50G15A - 6 Blinks- Bad TNPA4782

I took out

Transistors labeled 30G123 at locations Q421 Q422 Q423 all tested short

Transistor labeled RJP6065 at location Q661 and it tested short.
After taking it out, my SMDiode D673 and D674 labeled K696 are now working properly.

I have not taken any other transistors or diodes out. However the 6 SMDiodes that I am still registering as bad are the following:

D503
D522
D524
D711
D618 is physically burnt
D865 is located in front of, and is also shorted with D621 and D622 so it more than likely is ok, I just have to take D621 and D622 out of circuit to make sure. However the other 4 diodes were all located near the Q421 Q422 and Q423 that I already took out, and they are still acting weird.

Here are the following readings I get with the SMDiodes in circuit with my DMM on diode setting.

D503 Black on cathode red on anode .348v red on cathode, black on anode .353v
D522 Black on cathode red on anode .473v red on cathode, black on anode .726v
D524 Black on cathode red on anode .473v red on cathode, black on anode .726v
D711 Black on cathode red on anode .459v red on cathode, black on anode .641v

Back to non surface mounted diodes, I have D401 and D402 registering shorts,

I have Q401 on diode setting registering 0v between the emitter and collector, and .037v between the gate and the emitter and since the emitter is shorted to the collector, I get the same result on the collector. Measuring with both cathode and anode on gate, I am getting .037 both ways. On ohms I am getting 59.1 ohms between gate and emitter/collector.
Q402 right next to it is the same thing except I am getting .044v on diode setting between collector/emitter and the gate, and with ohms I am getting 70.8ohms.
Q403 emitter and collector shorted as well, but is giving me with anode on gate .568v on diode setting, and with cathode on gate, .993v.
In ohms I get about 47Kohms.
So I am not 100 percent sure what the deal is with those, but I am assuming Q403 is good but Q401 and Q402 need replacement.

D641 is showing on diode mode .338v going both ways.
Q601 shorted
Q441 shorted

So far this is what I found. I tried looking at some of the resistors near the transistors that went out, all tested good, I tried testing the IC's but then I realized I had no clue how to and decided to do that tomorrow once i have a chance to look over all of your back and forth replies once more to see how you tested them and what results you got so I can compare from there.

That's where I am right now, but I am going to take it slow and for sure will not plug this thing back in until I have a chance to test every single component on it haha.
However, I was able to find a few of the fets/diodes, and unless I want to pay $10 per component, I need to order from china, so I was hoping to start ordering some of those parts ASAP so I don't have to wait to long.
Also I have 2 of these exact same TV's with similar problems. This is the board that I have found has less problems, the other seems to have way more components that have gone bad, so I wanted to start on the easier one first.

Lastly here are all the locations and part numbers that I have found to be bad or think they are bad.

Driver IC M81707FP IC521 IC501 no clue how to test, but every repair kit has them and it seems like it went bad for you guys as well.
30G123 Q421 Q422 Q423
45G127 Q441
RFUS20-TM6S D401 D402
2pg011 Q401 Q402 Q403 these I am not 100 percent if all bad or if q403 is good
RF2001-TM3SW D621 D622 D641
RJK6026 Q601
RJP3034 Q621 Q622
RJP6065 Q661

Let me know what you think.
Thanks for taking the time to even read all of this, I know it's very confusing the way I presented it, I barely understand it when it's all separated out, but I have no idea how to properly organize it and what is connected together.

Thanks again

[tw2005]

Re: TH-P50G15A - 6 Blinks- Bad TNPA4782

I am currently attempting to repair my board, TNPA4782ab and I found that a lot of the components you talked about were also faulty on my board as I followed the same measurements as you showed in previous replies. However, I don't usually do many board repairs unless its basic Diodes caps, and or certain surface mounted components such as EEPROM chips, or fuses.
Because of the above statement, I have no idea where to buy these spare surface mounted diodes, IC's and or transistors. A few of the IC's I was able to find on ebay, but some of the transistors when typed in show up with a few different options. For example, RJK6026, I get RJK6026 and RJK6026DPP. What does the DPP at the end mean, and is there a difference? If so, which would I need?
Also I have no clue where to buy the surface mounted diodes. I have about 8 of them registering shorts, and the only symbols on them are K696 for 4 of them and the other 4 say 8897.
Thanks for the help.

DPP is merely the package type in Renesas speak I guess. needs to be TO220 Full Plastic casing.

As for the diodes, a little suprised you have not correlated 8897 which is actually marking 88 as the same as D618 mentioned in previous posts.

That also means K696 is in fact marking K6 made by Shingenden.

before you rush off and start getting bits, I'd remove the suspected shorted IGBTs first. then recheck the diodes, i suspect the K6 you refer to are in front of Q661/660.

Watch out for open cct pcb tracks where ever there is evidence of burning.

You could try UTSOURCE (will take weeks to arrive)or a kit but not just any kit. get a list together of what you find.

8 diodes sounds more than what i found but there's a number of ways these can fail I suspect. I would be more specifc with the info like exact locations.

i've only done 2 and only a small amount of info shared on self repair here.

[Nick's Tvs]

Re: TH-P50G15A - 6 Blinks- Bad TNPA4782

I am currently attempting to repair my board, TNPA4782ab and I found that a lot of the components you talked about were also faulty on my board as I followed the same measurements as you showed in previous replies. However, I don't usually do many board repairs unless its basic Diodes caps, and or certain surface mounted components such as EEPROM chips, or fuses.
Because of the above statement, I have no idea where to buy these spare surface mounted diodes, IC's and or transistors. A few of the IC's I was able to find on ebay, but some of the transistors when typed in show up with a few different options. For example, RJK6026, I get RJK6026 and RJK6026DPP. What does the DPP at the end mean, and is there a difference? If so, which would I need?
Also I have no clue where to buy the surface mounted diodes. I have about 8 of them registering shorts, and the only symbols on them are K696 for 4 of them and the other 4 say 8897.
Thanks for the help.

[tw2005]

Re: TH-P50G15A - 6 Blinks- Bad TNPA4782

Picked up a broken Rev AC 46" board. virtually no diiference between this and an AB 50" (G10) except placement of the inductors and a couple of caps.

Q601, RJK6026 shorted
Q661, RJP6065, shorted
Q441, 45G127 shorted
Q451, 45G127 _ shorted but not the same as 441, I suspect that when 441 is out this may be ok
Q701, MMBTA92 blown out
Q702, 2PD601 blown out
Q818, 2SK3018 could be ok
Q604 2SJ281 no short but i'm unsure still what they should do in cct. Not cracked apart like the last one
Q551 CPH5524_ shorted
D608, MA8120M, MAZ81200ML 12V 150mW zener(DIODE ZENER 12V 150MW SMINI2) _ open cct

D618 RF101L4S 400V 1A blown apart
R613 47K reads ok but burnt.
IC771 showing short O/P , 724,725 78L05 _ seem ok

IC773(bad),564 ok, 464,465 suspect_ TC7SH14F

IC521 M81707FP blown out

R521,522 100ohm 5% metal _ visually look ok but R521 is high at 108ohms, R522 appears open at 5.6K so both will need replacing.

IC561,562 appear to have not been shorted this time

New for me , opto PC601 has exploded

Usual scorched tracks

tracks blown off at D618, R613

Of the 3 inverter ICs 773,464,465. 464 on this occasion had 3.3ohms vcc-gnd. normally 773. all 3 are on the same 5v rail IC771

[tw2005]

Re: TH-P50G15A - 6 Blinks- Bad TNPA4782

Picked up a broken Rev AC 46" board. virtually no diiference between this and an AB 50" (G10) except placement of the inductors and a couple of caps.

Q601, RJK6026 shorted
Q661, RJP6065, shorted
Q441, 45G127 shorted
Q451, 45G127 _ shorted but not the same as 441, I suspect that when 441 is out this may be ok
Q701, MMBTA92 blown out
Q702, 2PD601 blown out
Q818, 2SK3018 could be ok
Q604 2SJ281 no short but i'm unsure still what they should do in cct. Not cracked apart like the last one
Q551 CPH5524_ shorted
D608, MA8120M, MAZ81200ML 12V 150mW zener(DIODE ZENER 12V 150MW SMINI2) _ open cct

D618 RF101L4S 400V 1A blown apart
R613 47K reads ok but burnt.
IC771 showing short O/P , 724,725 78L05 _ seem ok

IC773(bad),564 ok, 464,465 suspect_ TC7SH14F

IC521 M81707FP blown out

R521,522 100ohm 5% metal _ visually look ok but R521 is high at 108ohms, R522 appears open at 5.6K so both will need replacing.

IC561,562 appear to have not been shorted this time

New for me , opto PC601 has exploded

Usual scorched tracks

[tw2005]

Re: TH-P50G15A - 6 Blinks- Bad TNPA4782

My 2SJ281 P-FETs (10) just arrived from Poland. 2.49GBP + ship. took 3 weeks from order date to Australia. Works out at $1.30 ea for me.

HFO Elektronik

http://www.ebay.com.au/itm/261478252...%3AMEBIDX%3AIT

[tw2005]

Re: TH-P50G15A - 6 Blinks- Bad TNPA4782

Progress!!! I decided to put back the original IC563 and finally it stays on! So it seems it does run without the Q604 FET.

Now I just need to make sure there are no problems with the buffers before I put them back on.

this is a new 4782AB on Ebay. the box has a date of march 2014, not sure if that's manufacture date or picking date but note the Vset cct removed.

second picture is from SJ

[Alastair E]

Re: TH-P50G15A - 6 Blinks- Bad TNPA4782

Maybe Tom, --Could it be that issue concerning the ERC Cap circuit being fully discharged at turn-on, demanding twice the normal current (Or thereabouts) to flow through the SUS_Up pair--which eventually say--sod it and go short, taking the SUS_Dn pair out and whatever else happens to be around at the same time....?

Just recalling something you mentioned a while back....

This 50G10B has been fine now for two days, --Dunno why it had those SOS7 and SOS4 codes logged....

[tom66]

Re: TH-P50G15A - 6 Blinks- Bad TNPA4782

I suspect that the 2011's would be fine with the heatsink-free boards but there's a software or hardware design flaw that causes them to fail early. Thermally speaking the transistors only run warm to the touch.

[tw2005]

Re: TH-P50G15A - 6 Blinks- Bad TNPA4782

Well--Not certain models for sure!

The older series like the TH-p42/50/PX/PZ/70/80/81 series are brilliant long lived reliable sets.
--Just a shame they double as room-heaters!

For sure, i think the PZ series are solid enough bar the PSU. I must admit I like the 2011 panels now I've seen them , the 2 I've done I'm happy with just transistor replacements, at least we know how to fix these cheap, not good for the average consumer I guess

[Alastair E]

Re: TH-P50G15A - 6 Blinks- Bad TNPA4782

I did'nt think you thought much of the panasonic plasmas either?

Well--Not certain models for sure!

The older series like the TH-p42/50/PX/PZ/70/80/81 series are brilliant long lived reliable sets.
--Just a shame they double as room-heaters!

[vinceroger69]

Re: TH-P50G15A - 6 Blinks- Bad TNPA4782

maybe something like this but it's a pack of 5 so over 20GBP

http://uk.rs-online.com/web/c/?sra=o...hTerm=flux+pen

http://uk.rs-online.com/web/p/solder-fluxes/2513637/

Thanks for the rs link i have a branch a short distance from me having five is no problem im sure they will come in handy for other project, im just looking on all my free sites local to see what project tvs are available why pay i say if i can pick them up for just the fuel cost.

[tw2005]

Re: TH-P50G15A - 6 Blinks- Bad TNPA4782

maybe something like this but it's a pack of 5 so over 20GBP

http://uk.rs-online.com/web/c/?sra=o...hTerm=flux+pen

http://uk.rs-online.com/web/p/solder-fluxes/2513637/

[tw2005]

Re: TH-P50G15A - 6 Blinks- Bad TNPA4782

cool thanks i have most of the stuff already minus flux pen (have you got a link which one you use) also need a jewlers loupe they always come in handy i guess cheers again.

No, just a generic flux pen from a local electronic shops Jaycar. Called No clean flux pen. They're not cheap about $12 AUD but for this work I find it invaluable.

[vinceroger69]

Re: TH-P50G15A - 6 Blinks- Bad TNPA4782

cool thanks i have most of the stuff already minus flux pen (have you got a link which one you use) also need a jewlers loupe they always come in handy i guess cheers again.

[tw2005]

Re: TH-P50G15A - 6 Blinks- Bad TNPA4782

my 2 very cheap irons, 20W & 40W with a quality tip in the 40w

Also a set of quality fine tip tweezers is handy for handling and placement of the SMD stuff

[tw2005]

Re: TH-P50G15A - 6 Blinks- Bad TNPA4782

Oh, I should mention FLUX, flux pen, makes a world of difference and flows so nice which is what you need to avoids bridges.

[vinceroger69]

Re: TH-P50G15A - 6 Blinks- Bad TNPA4782

Thanks for the information.

[tw2005]

Re: TH-P50G15A - 6 Blinks- Bad TNPA4782

Just read this post from start to finish a good fix and some good info on test procedures etc whats the rough cost for the parts per board? compared to a good used one? Not everyone maybe able to complete this fix i guess due to small parts (smd)?.Can this repair be carried out with just a soldering iron or do you need hot air station? cheers for any advice you can offer. I havnt got a board needing repair but having this info in advance is always handy for myself and maybe other members.

I only have the most basic gear, use 2 irons to remove these smaller items heating both sides and use the tips to move them. I have a headband magnifier and a 5x loupe to get a good look at the finer pitch items like those 20 pin octal buffers which are large compared to the 5081 boards. have tried flooding the pins on the FET drivers but mixed results and the heat easily lifts the no connection pads plus very cramped.

I think anyone who has hot air and experience may do a better job.

maybe one day I'll get a cheap Hot air station and have a go

Cutting the pins makes it easy and I think once you've done a few for what these parts cost better to just replace and treat these drivers as suspect but I must admit with so litle blown on my first 4782 I got lazy and skipped it.

Going to depend on how much is blown as i've read a lot more IGBTs need replacing so plenty of scope for these to be hard.

sometimes you just have to have a go to learn and not give up if possible.

I would say about $20, going to depend on where you get the bits, qty purchased and you'd be mad not to get extras just in case so the first board may need a $40 investment.

looking at the time and possibility of failure, what people charge is probably cheap really for the effort but the more boards you do the more knowledge and more efficient you get.

I think it's fun but lets face it if nobody tried then there'd be a lot of tvs not repairable due to no boards available and buffers are a concern now. i keep all the dead boards just in case and for learning. I'd like to have a go at buffer rebuilds but too expensive for the panasonics i feel and I think hot air would be a safer option.

looking at these 4788,89 buffers, 8 Ics, about $50-60 AUD and you only need to stuff one track up and it's all over, very risky for me at least.

Both of the boards i killed all 8 ics have 1 shorted pin

[vinceroger69]

Re: TH-P50G15A - 6 Blinks- Bad TNPA4782

Just read this post from start to finish a good fix and some good info on test procedures etc whats the rough cost for the parts per board? compared to a good used one? Not everyone maybe able to complete this fix i guess due to small parts (smd)?.Can this repair be carried out with just a soldering iron or do you need hot air station? cheers for any advice you can offer. I havnt got a board needing repair but having this info in advance is always handy for myself and maybe other members.