Panisonic 42inch TCP42S30 not working!!

[Waggy]

My Panasonic TCP42S30 suddenly turned off when I was watching it. I unplugged it and plugged it back in and still nothing happened, but when I turn it on the red light blinks 14 times then pauses and blinks 14 times again. It also has no picture AND no sound. Help!?

[guyonphone]

Re: Panisonic 42inch TCP42S30 not working!!

Hello Waggy,
Have you opened up the back and checked the power supply for bulging/leaking capacitors, that's where I would start.

[capkid]

Re: Panisonic 42inch TCP42S30 not working!!

Panasonics don't normally have cap issues. Here's a thread for a similar issue:

https://www.badcaps.net/forum/showthread.php?t=23815

I wouldn't jump to the conclusion reached in the thread I provided without doing some checking.

[Waggy]

Re: Panisonic 42inch TCP42S30 not working!!

Yes I opened the back. Everything looked fine from what I could see.

[RJARRRPCGP]

Re: Panisonic 42inch TCP42S30 not working!!

My Panasonic TCP42S30 suddenly turned off when I was watching it. I unplugged it and plugged it back in and still nothing happened, but when I turn it on the red light blinks 14 times then pauses and blinks 14 times again. It also has no picture AND no sound. Help!?

May have been damage from a poco issue. Did you see anything else in the building stop briefly?

[tw2005]

Re: Panisonic 42inch TCP42S30 not working!!

As per CAPKID, Check for shorted Vsus lines on the SN and SS boards. You can get wrong and some weird SOS blinks when there's a dead short on those.

https://www.badcaps.net/forum/showth...RJP30E4&page=2

https://www.badcaps.net/forum/showth...ight=tc-p42s30

https://www.badcaps.net/forum/showth...ight=tc-p42s30

[Waggy]

Re: Panisonic 42inch TCP42S30 not working!!

I have tried replacing the power supply board but still has 14 blinks, suggestions?

[capkid]

Re: Panisonic 42inch TCP42S30 not working!!

Did you check the link I posted? The original poster had a bad SS. Again, I'd read through that thread and test before assuming that replacing the SS board will solve your problem.

[tw2005]

Re: Panisonic 42inch TCP42S30 not working!!

I have tried replacing the power supply board but still has 14 blinks, suggestions?

As what CAPKID mentions, read post 3, check the link out, read my post 6 and check those links.

Check this link out also https://www.badcaps.net/forum/showthread.php?t=30502
as I have additional info regarding 14 blink and solid LED indication. Post 2 and guide in post 3 should be of some use.

Most likeley will be shorted SN or SS boards, not the PSU as you have worked out with a replacement and no change.

14 blink
Shorted F15V developed after the TV is up and running.

Holding the power switch for over 5 seconds after the unit has gone into shut down and it’s in lock mode with the power LED solid red (Note: the LED stays on if the power button is momentarily pressed).

[Hok]

Re: Panisonic 42inch TCP42S30 not working!!

Hi folks, complete novice here with the same issue on Panasonic TC-P42S30 set. I am a veteran DIY'er but not very knowledgeable of electronics. However, I'm ready and courageous enough to dive in and give this a shot.

Thanks to tw2005, Tom, and other users on this forum, as well as austech forum and the great training manual that Tom uploaded, I have narrowed down my issue to the SN board.

I would like to continue troubleshooting the board, but I am unable to do so without a bit of help. I hope that some of you might step to my aid...

I believe I have identified 4 bad IGBT's and have lifted their legs, but would like to verify that and continue to test other components on the board if possible. I don't know if I am testing the resistance at SN2 pins properly. With Com lead on pin 1 I get 31k Ohms, but with leads reversed i get a short. Which one should I believe?

And, how should I proceed to test other components on the board? I am trying to test mosfets but am getting varied readings and can't figure out which ones, if any, are bad.

Could it be that the four I found are the only bad parts... (the gates don't close when i try to short drain-gate, so I'm guessing this means they are bad.)

Would love to continue this project, so if anybody could offer a good place to start I'd be very grateful.

[Hok]

Re: Panisonic 42inch TCP42S30 not working!!

Would anyone care to walk me through the troubleshooting of the SN board?
I have removed q401, q402, q421, and q422 from the board. Bit of a pain with a 25 watt iron...
I am still getting a short at SN2 from pin 1 to pin 3 (though I'm not sure i'm doing this right - assume com goes to ground as always i.e.- red to pin 1 and com to pin 3)
However, I am testing other components which are included in the #$# repair kits on ebay and can't be sure if 1) the results are correct, since they are all in circuit and 2) what kind of results i'm looking for and 3) If I remove all failed components without replacing them would the short at SN2 miraculously disappear?

any takers?

[Glitcher]

Re: Panisonic 42inch TCP42S30 not working!!

I just recently repaired a TCP46S30 with an SC board failure, with the usual 3 bad fets. The short between the main connector should be gone when measuring in both directions. If all the bad components are removed, the short should be gone. At least on my model it did, but im not sure if its the same.

[Hok]

Re: Panisonic 42inch TCP42S30 not working!!

Thanks, Glitcher... Is it possible to test the mosfets that remain without lifting a leg? I did just lift a leg on one common culprit and it's reading 0 ohms now, whereas is was 46K ohms before lifting the leg so perhaps i'm doing something wrong?

[Hok]

Re: Panisonic 42inch TCP42S30 not working!!

Perhaps only 3 of these igbt were bad - 3 read resistance of 9-12 Ohms, while the fourth reads 0.2 Ohms. nevertheless, still getting a short at SN2

[Hok]

Re: Panisonic 42inch TCP42S30 not working!!

ok just found 4 more - apparently shorted fets, lifted the legs and they won't pass voltage (tried the open gate then test for falling voltage) neither do they have any resistance, so i've either destroyed them or they're destroyed already.... these are Q451, Q441, D621, D622... Still have a short, but only in one direction (red to pin 1 and com to pin 2) other direction reads great

[Glitcher]

Re: Panisonic 42inch TCP42S30 not working!!

some of the fets are actually in parallel so if one is shorted, both will appear shorted, so youll have to lift the leg to actually figure out which is bad.

Also keep in mind, that not all of them are fets, but some are also diodes which will measure shorted from pins 1 and 3 (this is normal).

What are the part numbers for the ones you found? and can you post a photo of the entire board?

[Hok]

Re: Panisonic 42inch TCP42S30 not working!!

will attempt to post a photo of the board, (TNPA5349)

those with no reading at all are the 2 DG302's (Q451,Q441) and 2 of the 30F131's (Q621, Q622)

Have already removed 401,402,421,422 and already I doubt whether or not I should have. Very confused so your advice is welcomed.

[tw2005]

Re: Panisonic 42inch TCP42S30 not working!!

easiest way to do a quick check is set the meter to diode or continuity check and probe between the legs. generally they'll go shorted across all 3. metal tab is what would be the center leg if these were through hole components.

Anything that constantly beeps is short would need to be removed or lift the legs as glitcher mentioned and confirmed bad out of cct.

No reading is normal as there is a special way needed turn the transistor on to check it but if it's not short I'd move on.

looking at some of the kits for sale, hard to tell if you'd get away with just the shorted IGBTs.

Here's the list which gives most locations, the rest would not be too hard to work out.

Q401,Q402,Q421,Q422,Q621,Q531,D401,D421,IC502,Q6??,R???,R???,R???,R???,R???

Another list from GTV watford which i would trust is for shorted SC

The kit also has 4 smd resistors, most likely gate resistor on the transistors but I'd check any in cct around that list of parts.

PARTS Q401 Q402 Q421 Q422 Q441 D401 D421
PLUS IC502 AND Q531 WILL FAIL IN 20% OF CASES

Q401 Q402 Q421 Q422 = B1JBDN000004 = GT30F131, Gate resistors R401,402,421,422 = D0GF7R5JA047, M 7.5 OHM,J, 1/3W

Q441= DG3C3020CL (DG302), gate resistor R441, D0GF5R6JA047, M 5.6 OHM,J, 1/3W

D401= B0FCCN000003 = RF1501NS3S

D421= B0FCBN000001 = RFN10NS3S

IC502 = C0ZBZ0001822 = BD8693FVM-HVTR,

Q531 = B1HFPFA00001 = CPH5524-TL-E, check R531 10ohm. R532 47k

[Hok]

Re: Panisonic 42inch TCP42S30 not working!!

Thanks, TW. You've been very helpful in the Panasonic threads i've been through here and elsewhere. You have caught on quickly to see that I'm having knowledge issues with testing the components...
Just to recap what you've said so that we're sure I'm clear:
1) using the diode (audible) test, which measures resistance, if I get a beep across the mosfets and igbts, then the component is likely bad and should be tested out of circuit. (To prove how much of a dummy I am, I thought it was the opposite - goes to show my lack of education in electronics would not get me far..) If this is the case, there appears to be a lot more mosFets than usual that are fried. [D642,D641,D461,D481,
2) How should i test them out of circuit? I have seen 2 ways - one with mm (open gate and check waning voltage,) and one with a power supply and small load that lights up when the gate is opened.
3) on the miniscule smd resistors - It appears that all 6 of those R's give a beep, even on the 2 'good' igbt's, and the 2 'good' DG302 at Q441 and Q451 - does this mean that all 8 of those are gone?

[tw2005]

Re: Panisonic 42inch TCP42S30 not working!!

Thanks, TW. You've been very helpful in the Panasonic threads i've been through here and elsewhere. You have caught on quickly to see that I'm having knowledge issues with testing the components...
Just to recap what you've said so that we're sure I'm clear:
1) using the diode (audible) test, which measures resistance, if I get a beep across the mosfets and igbts, then the component is likely bad and should be tested out of circuit. (To prove how much of a dummy I am, I thought it was the opposite - goes to show my lack of education in electronics would not get me far..) If this is the case, there appears to be a lot more mosFets than usual that are fried. [D642,D641,D461,D481,
2) How should i test them out of circuit? I have seen 2 ways - one with mm (open gate and check waning voltage,) and one with a power supply and small load that lights up when the gate is opened.
3) on the miniscule smd resistors - It appears that all 6 of those R's give a beep, even on the 2 'good' igbt's, and the 2 'good' DG302 at Q441 and Q451 - does this mean that all 8 of those are gone?

diode mode measures voltage drop.

Constant beep is short or low resistance. short beep and a reading is not but on low resistance it will be a continuous beep. Depends on the quality of the meter. I think with mine anything below 100ohms will beep constant.

The only items I would use the buzzer on are the semiconductors, eg transistors and diodes. For the resistors go resistance and measure in cct. If they measure their value or a bit lower that would be ok. generally the resistors burn out and either go high resistance or open cct.

Sometimes if you look real close there will be burning or an exit hole where they've failed.

To keep this simple, set meter to diode, on the smd transistors place one probe on the tab and the other on each of the legs one at a time and observe. If the meter beeps constant and reads low like 0 or 0.01 etc, that's dead short, then would have to remove or lift legs to confirm in case another transistor is shorting the tested one.

On the SMD diodes, do the same, one polarity no reading, reverse probes and if good will get short beep then reading, could be 0.3 -0.7 as a guide. leg to leg though will show short as they are both the same . tab is cathode, legs are anode. again a constant beep in both directiions would indicate bad but again lift the legs to confirm.