Another Panasonic Plasma (TX-P50GT30E) with 7 blinks of death

[mcflyfarm]

Three weeks ago, my Panasonic TX-P50GT30E also faulted with "7 blinks of death" during home-cinema.

My first question:
What's the difference between TX-P... and TC-P... models? I've found a service manual for TC-P50GT30 (from electrotanya -> panasonic_tc-p50gt30_chassis_gpf14du.pdf), but I'm not sure, if it's the correct one for my TX-model?!

Boards:
SC = TNPA5335AG
SU = TNPA5336AG
SD = TNPA5337 (no AG or any other suffix)

First step: I disconnected SC-board from SC2-connector: for 1-2 seconds the multimeter beeps (continuity-test), then it shows 'overload' (high resistance) and no more beeps; when I do the same test in reverse (exchange the direction), the same happens. Checking SC2-connector with Ohmmeter shows 'overload', too.

Second step: I did the SD/SU-buffer-isolation test like frequently recommended by "tw2005" (re-connected SC2, jumperred SC50, isolated both SD/SU-boards from SC by disconnecting the 3 white bridge-connectors, unscrewed the 4 GND-screws (I was surprised, that all of them had already spring-washers installed; screws were hard to loose) between SC and SU/SD and isolated the GND-plates with thick paper between these boards).
Then I ran the isolation-test and still got "7 blinks of death".

Thirdly: I checked the buffer boards and determined, that SD had no shorts, but SU has several shorts on SU3 and SU4 connectors to the PDP! I don't disconnected the flat cables between SU3/SU4 to the PDP at this point.
Because repairing the SU would be a hard job, I've ordered a set of SD+SU(AG)-boards by ebay for 50 Euros: these boards are clean, having no shorts on the connectors; should be good...

Can a SU or SD buffer kill SC-board, or is it vice versa?
Or could the panel be faulty, causing a cascade of shorts from PDP to SU and then to SC?

Besides:
What differs the suffix between TNPA5335AG,...BG,...BH, etc.? Are these boards compatible to each other? Is it possible to use an AG-board (SC) with SU/SD-buffer differently suffixed, and vice versa?


Next I will determine shorts for following components on the SC:
Q401-403, Q421-423, Q531, D401-402, IC502, R401-403 and R421-423
Are there more to test?
Should I desolder before testing with multimeter?

Kind Regards
Martin

[Moreno83]

Re: Another Panasonic Plasma (TX-P50GT30E) with 7 blinks of death

I'll answer when i get home from work!

[Moreno83]

Re: Another Panasonic Plasma (TX-P50GT30E) with 7 blinks of death

I added a picture.

The difference between the TX and TP is that TX is used in Europe and TP is mostly American/Canadian models but the basics are the same. They do use different boards.

7 Blinks for this model is usually the SC board that is shorted deu to screws that are loose. Board starts arching between ground and the board and the board gets shorted.
It is best to measure the SU/SD boards outside of the tv. Black prope on the screw hole and slide the red prope against the copper pins. Beep is bad. Watch out though , there are small ground holes on the board. Dont get confused. Make sure the multimeter is in diode/beep mode.

A shorted su/sd board could be to a shorted panel but usually it's just 1 or 2 chips that get shorted.
When those SU/SD boards get shorted they can short out the SC board. If you disconnected the SU/SD board from the SC board and used the SC50 jumper and still 7 blinks then the board is shorted.
If the SU/SD is the main problem you need to measure the 30F131 close to the white connectors. Take a look at the picture , its the top side area.

There are 2 rays of FETS on the board. Top side and lower side. The top side with RFN20/30F131 are usually shorted because of bad SU/SD board.
The lower area with just 30F131/RJP30H2A close to the capacitors are shorted when the screws are the problem.

If you have found the defective area which is probably the top area then measure the OUTER pins on the 30F131 in diode mode. Beep is bad.
If you get a short then remove ALL the defective 30F131 and then measure the diodes to see if they are still shorted.

You need replacement parts to fix the sc board. Dont buy repair kits but buy FGD4536TM from a GOOD seller. There are to many fakes on the market.
If you cant find the parts then buy a SS board from your model , the parts you need are on that board.

Good luck! Let me know the outcome.

[mcflyfarm]

Re: Another Panasonic Plasma (TX-P50GT30E) with 7 blinks of death

Hello Moreno,

First, Thanks for your reply. I also added a pic.

When I ran the SD/SU-isolation-test with SC50-jumper and disconnected buffers, the SC also gone in 7 blinks of death (as I wrote in my first post).

OK. The SD/SU and SC are now outside the tv. As mentioned in my first post, the SD has no shorts; SU has several shorts at SU3 and SU4.

There are 2 rays of FETS on the board. Top side and lower side. The top side with RFN20/30F131 are usually shorted because of bad SU/SD board.
The lower area with just 30F131/RJP30H2A close to the capacitors are shorted when the screws are the problem.

The GND-screws holding the buffer-boards on the SC were realy hard to loose and had already spring washers installed. Maybe here did learn Panasonic from failures from past?!

Now the SC:
Diode-test beep on following items:
D421 (DAF30A)
D401 (RF1501)
D432 (RNF10)
D641-643 (RNF20)
driver IC502 between 1-8

It seems that both areas are affected... I'm wondering, that all the PDP-IGBT (Qxxx) having no shorts, but only the diodes?!

You need replacement parts to fix the sc board. Dont buy repair kits but buy FGD4536TM from a GOOD seller. There are to many fakes on the market.
If you cant find the parts then buy a SS board from your model , the parts you need are on that board.

At this point I hope not need to seek for Fairchild IGBT FGD4536TM, because like PDPs are extinct, the PDP-IGBT seem also to be extinct. Very hard to find a seller in EU and propably components from china are most fakes.

I remarked the shortet items in your picture with a yellow dot (please see attachment).

Could there be another bad caps on SC, that should be tested?

As a first step I'll replace the diodes first. What Do you think about IC502 Pin 1-8 short?

Kind Regards
Martin

[Moreno83]

Re: Another Panasonic Plasma (TX-P50GT30E) with 7 blinks of death

Hello Moreno,



OK. The SD/SU and SC are now outside the tv. As mentioned in my first post, the SD has no shorts; SU has several shorts at SU3 and SU4.



The GND-screws holding the buffer-boards on the SC were realy hard to loose and had already spring washers installed. Maybe here did learn Panasonic from failures from past?!

Now the SC:
Diode-test beep on following items:
D421 (DAF30A)
D401 (RF1501)
D432 (RNF10)
D641-643 (RNF20)
driver IC502 between 1-8

The big screws for the su/sd boards all have lockwashers except the screws on the board itself. So no , you have a standard model with 7 blinks.

DAF30 and RF1501 will probably read short because other parts are shorted. Most likely only the diodes on the top board are shorted , funny the fets itself are not shorted......
You did test ALL parts in diode mode?

Parts labeled with Q you need to measure the OUTER legs. ( 30F131/RJP30H2A).

Parts labeled with D you need to put black prope on middle pin and red on either left or right leg. Beep is usually bad. ( RF1501/RFN20 ).

Your shorted buffer board probably took out the SC board OR you did not short the sc50 jumper correctly. SC20 cable is still connected?

[mcflyfarm]

Re: Another Panasonic Plasma (TX-P50GT30E) with 7 blinks of death

Hi Moreno,

Parts labeled with Q you need to measure the OUTER legs. ( 30F131/RJP30H2A).

Parts labeled with D you need to put black prope on middle pin and red on either left or right leg. Beep is usually bad. ( RF1501/RFN20 ).

I'll try another approach tomorrow after work.

Your shorted buffer board probably took out the SC board OR you did not short the sc50 jumper correctly. SC20 cable is still connected?

When I did the SD/SU-isolation test to SC, I jumperred SC50 with an IDE-HD-jumper; this should be OK?!
Yes, SC20 flat-cable was connected during this test.

Kind Regards,
Martin

[Moreno83]

Re: Another Panasonic Plasma (TX-P50GT30E) with 7 blinks of death

Hi Moreno,



I'll try another approach tomorrow after work.



When I did the SD/SU-isolation test to SC, I jumperred SC50 with an IDE-HD-jumper; this should be OK?!
Yes, SC20 flat-cable was connected during this test.

Kind Regards,
Martin

Ok good because if you measure the parts wrong you will look for a fault that is not there....

HD jumper should be ok but i had issues with hd jumpers. I use a screw and make sure it shorts the pins in combination with the little plastic.

Let me know the outcome! Dont throw the tv away or sell it for cheap , these models give a very nice picture!! You wont get better unless you buy oled.

[mcflyfarm]

Re: Another Panasonic Plasma (TX-P50GT30E) with 7 blinks of death

Hi Moreno,

Sorry for the delayed answer, but I have some issues with my geese-farm and agriculture from time to time (offtopic).

Parts labeled with Q you need to measure the OUTER legs. ( 30F131/RJP30H2A).

Parts labeled with D you need to put black prope on middle pin and red on either left or right leg. Beep is usually bad. ( RF1501/RFN20 ).

My multimeter has both a diode-test-mode (but no beep) and an acoustic-continuity-test-mode (when value is less than 30 Ohms, then it signals beeping sound, otherwise it shows O.L. (=overload, meaning a very high Ohm-value)).

I did both variants:

Q401: diode-test = 0.931 (falling value), continuity-test = O.L.
Q402: diode-test = 0.929 (falling value), continuity-test = O.L.
Q403: diode-test = 0.930 (falling value), continuity-test = O.L.
Q621: diode-test = 0.931, continuity-test = O.L.
Q622: diode-test = 0.930, continuity-test = O.L.
Q623: diode-test = 0.930, continuity-test = O.L.
Q421: diode-test = 0.930, continuity-test = O.L.
Q422: diode-test = 0.930, continuity-test = O.L.
Q423: diode-test = 0.930, continuity-test = O.L.
D421: diode-test = 0.343, continuity-test = 397 Ohm
D401: diode-test = 0.412, continuity-test = O.L.
D432: diode-test = 0.472, continuity-test = O.L.
D641: diode-test = 0.418, continuity-test = O.L.
D642: diode-test = 0.418, continuity-test = O.L.
D643: diode-test = 0.417, continuity-test = O.L.

When testing the IGBT (Qxxx) in diode-test-mode I hold red probe to E (emitter) and black probe to C (collector) - the outer legs (as you described). The Q40x IGBT are showing a falling value during diode-test, the others are holding it's value almost constantly.

When testing the diodes, I took black probe to middle leg and red probe to one outer leg (also as you described). Don't you think, I have to test the diodes always from middle leg to left leg and then middle leg to right leg and in both directions (anode to cathode and vice versa), or not?

Do these values have a meaningfulness for you?
Are there any other components to test?

Dont throw the tv away or sell it for cheap , these models give a very nice picture!! You wont get better unless you buy oled.

No - I won't give up my lovely plasma, because I know it's more better picture than a standard-led-tv


Kind Regards
Martin

[Moreno83]

Re: Another Panasonic Plasma (TX-P50GT30E) with 7 blinks of death

Personally i would remove Q621/22/23 and measure again.
I only measure in continuity mode ( beep ) on the outer legs. Beep is bad.

I got one of these boards at home , will measure it for you.

[mcflyfarm]

Re: Another Panasonic Plasma (TX-P50GT30E) with 7 blinks of death

Hello,

Dont buy repair kits but buy FGD4536TM from a GOOD seller.

Do you know a good seller? Most of them (in EU/US) don't have this item in stock anymore... Only way would be a reliable, trustworthy seller in asia...?!

Personally i would remove Q621/22/23 and measure again.
I only measure in continuity mode ( beep ) on the outer legs. Beep is bad.

OK. I'll remove Q621/22/23 with my SMD-rework-station and measure the remaining parts again. I'll write back here soon...

I got one of these boards at home , will measure it for you.

This would be nice

Kind Regards
Martin

[mcflyfarm]

Re: Another Panasonic Plasma (TX-P50GT30E) with 7 blinks of death

Hello Moreno,

Personally i would remove Q621/22/23 and measure again.
I only measure in continuity mode ( beep ) on the outer legs. Beep is bad.

What is the recommended temperature for de-soldering these components with smd-rework hot-air? I don't want to kill potentially good items using too high temperature during hot-air-desoldering?
I tried with 280°C-320°C but no chance to remove from board...?

Kind Regards
Martin

[Moreno83]

Re: Another Panasonic Plasma (TX-P50GT30E) with 7 blinks of death

I use a simple 60W solder iron. ( 40W wont work ). When you use a big tip and apply some solder to the back of the fet the fet will come of pretty quickly.....
I just cut the legs and then apply solder to the part.
I dont use hot air , it bends the board if you do it wrong and it might damage other components.
Just a simple 60W iron will do the trick.

They cost 20 euro in NL!

[tvtimmy]

Re: Another Panasonic Plasma (TX-P50GT30E) with 7 blinks of death

Watch this video. Not your board but it shows how to remove the parts.
TNPA5335 Repair Kit on youtube.

[mcflyfarm]

Re: Another Panasonic Plasma (TX-P50GT30E) with 7 blinks of death

Hello Moreno, Hello tvtimmy,

I dont use hot air , it bends the board if you do it wrong and it might damage other components.

In Youtube Video by ShopJimmy the guy is using hot air (video ID UmJYQ7oEbKg). But they don't tell about, which temp. to use for de-soldering and re-soldering the IGBTs? So I was almost sure, that these method should work, too, with my SMD-rework-station....

But OK:

I use a simple 60W solder iron. ( 40W wont work ). When you use a big tip and apply some solder to the back of the fet the fet will come of pretty quickly.....
I just cut the legs and then apply solder to the part.

Watch this video. Not your board but it shows how to remove the parts.
TNPA5335 Repair Kit on youtube.

YEP - that was the trick! Thx!
I used the solder iron station from my brother and so I successfully removed Q621/22/23. Next step I'll measure the remaining parts onboard again (the same way as you mentioned above (red/black probes to correct pins)). I'll post the results soon...

Kind Regards
Martin

[mcflyfarm]

Re: Another Panasonic Plasma (TX-P50GT30E) with 7 blinks of death

Hello Moreno,
Hello tvtimmy,

Today I measured again the remaining parts after removed Q62x (2.test in following table):

Item  Type     1. cont.-test   1. diode-test   2. cont.-test   2. diode-test  
Q401  30F131       o.l.      <=0,931       o.l.       0,881    
Q402  30F131       o.l.      <=0,929       o.l.       0,882    
Q403  30F131       o.l.       <=0,93       o.l.       0,881    
Q421  RJP30H2A      o.l.       0,930       o.l.       0,947    
Q422  RJP30H2A      o.l.       0,930       o.l.       0,947    
Q423  RJP30H2A      o.l.       0,930       o.l.       0,947    
Q621  30F131       o.l.       0,931      (removed)     (removed)   
Q622  30F131       o.l.       0,930      (removed)     (removed)   
Q623  30F131       o.l.       0,930      (removed)     (removed)   
D401  RF1501       o.l.       0,412       o.l.       0,414    
D421  DAF30A      397 ohm      0,343       o.l.       0,344    
D432  RFN10       o.l.       0,472       o.l.       0,473    
D641  RFN20       o.l.       0,418       o.l.       0,418    
D642  RFN20       o.l.       0,418       o.l.       0,418    
D643  RFN20       o.l.       0,417       o.l.       0,418

Qxxx (IGBTs): the outer legs
Dxxx (diodes): black probe on middle leg, red probe to left and/or right leg.

I'm looking forward for your reply

@Moreno:
Next I should order some/several of the IGBT Fairchild replacements for 30F131 from the good seller you sent me in your PN...?!

Kind Regards
Martin

[mcflyfarm]

Re: Another Panasonic Plasma (TX-P50GT30E) with 7 blinks of death

Hello Moreno83,

I hope you're still active here...

TNPA5335-AG

After more than a year, the in 2018 repaired SC-board, gone to 7 blinks again. I dismounted this from the TV and recognized, that Q401 was not properly soldered (Gnd plate). Should be easy to repair...

So I decided to replace this SC with a second spare SC-board which worked fine in 2018, but after mounting into TV I get also 7 blinks. When disconnecting the buffer-boards (SU,SD) and jumpering SC50 (isolation test mode), the board starts successfully (SC-onboard green LED get's on; no 7 blinks). There are no shorts reading on any of the ribbon connectors from both buffers to PDP. Re-connected the SC to the buffers and removed SC50 jumper, start up fails with 7 blinks again...

The also no shorts reading on any of the D- or Q-labelled parts; all diodes and IGBT seem to be OK.

Have you any hint, which part in the recovery-unit-area could be bad and how to test this?
Could there be a problem with the buffers, despite of having no shorts at the ribbon-connectors?

I'll also try to solder the Q401 on the first SC mentioned above and give these SC a try... But I would be glad to have a second spare of TNPA5335 as a replacement.

Kind Regards,
Martin

[mcflyfarm]

Re: Another Panasonic Plasma (TX-P50GT30E) with 7 blinks of death

What differs the suffix between TNPA5335AG,...BG,...BH, etc.? Are these boards compatible to each other? Is it possible to use an AG-board (SC) with SU/SD-buffer differently suffixed, and vice versa?

Regarding two my question in my first post, a technician in china gave following answer, now:

The two versions of the TNPA5335 (BA BL) board are typically used on 55-inch TVs. (BG AG) is usually used on a 50-inch TV. (BH AH) is usually used on a 46-inch TV.

Martin

[mcflyfarm]

Re: Another Panasonic Plasma (TX-P50GT30E) with 7 blinks of death

After more than a year, the in 2018 repaired SC-board, gone to 7 blinks again. I dismounted this from the TV and recognized, that Q401 was not properly soldered (Gnd plate).....
....
I'll also try to solder the Q401 on the first SC mentioned above and give these SC a try... But I would be glad to have a second spare of TNPA5335 as a replacement.

After re-soldering the Q401 IGBT, I found the diode D421 (DAF30A) was dead; I exchanged the component.

The story goes on:
Now it's interesting, that BOTH SC-boards start up successfully within the buffer-isolation-test (disconnected SU/SD, jumpering SC50) without 7 blinks and the green on-board LED on SC turns on.

But: BOTH SC-boards don't start up regularly with connected buffers and 7 blinks of death is back - with BOTH!

1. Can 7 blinks indicate also, that one or both buffer-boards are bad?
2. Or is there a problem within the energy-recovery-section on BOTH SC?
3. If yes, which components could be faulty? Where ist the recovery-section located on SC?

Who can help me?


Kind Regards,
Martin

[mcflyfarm]

Re: Another Panasonic Plasma (TX-P50GT30E) with 7 blinks of death

After re-soldering the Q401 IGBT, I found the diode D421 (DAF30A) was dead; I exchanged the component.

Currently I investigate in my second (spare, replacement) SC-board. I exchanged switcher IC (IC502) and a double transistor (Q531).
This board starts up resulting in 6 blinks now (both buffers are isolated).

Have to explore more and more...

Any hints?

Martin