Panisonic 42inch TCP42S30 not working!!

[Hok]

Re: Panisonic 42inch TCP42S30 not working!!

Aah, I see how i got the reference per your diagram - because Q531 is sitting to the right of IC502... this gives me a reference for the others; will report results shortly then go off to check the IC's on the SS card.

In addition, IC502 DOES have numbers PRINTED on it, (not imprinted) - just had to be at a severe angle to see them. Same numbers.

[Hok]

Re: Panisonic 42inch TCP42S30 not working!!

IC501
PIN 1 .535 M Ohms and still rising slowly after 30 secs
PIN 2 .465 M Ohms steady
PIN 7 28.3 M Ohms decreasing (30 seconds)

IC684
PIN 1 .597 M Ohms and still rising slowly after 30 secs
PIN 2 .464 M Ohms steady
PIN 7 6.04 M Ohms steady

IC502
PIN 1 .566 M Ohms and still rising slowly after 30 secs
PIN 2 .469 M Ohms steady
PIN 7 28.8 M Ohms decreasing (30 seconds)

IC522
PIN 1 17 k Ohms steady
PIN 2 4.72 k Ohms steady
PIN 7 25.2 M Ohms steady

IC521
PIN 1 17 k Ohms steady
PIN 2 4.77 k Ohms steady
PIN 7 24.89 M Ohms steady

Q501
24.6 M Ohms & 24.38 M Ohms
Q522
24.07 M Ohms & 24.03 M Ohms
Q531
24.68 M Ohms & 24.34 M Ohms
Q551
24.08 M Ohms & 23.99 M Ohms

[Hok]

Re: Panisonic 42inch TCP42S30 not working!!

I see that IC521 and IC522 (while similar) are different than the others, but I do see pin 7 at IC684 has a sizable variance compared to the others, which came in at similar readings on pins 1 and 2.... Do you need the reference data/measurements from the SS board as well?

[tw2005]

Re: Panisonic 42inch TCP42S30 not working!!

I see that IC521 and IC522 (while similar) are different than the others, but I do see pin 7 at IC684 has a sizable variance compared to the others, which came in at similar readings on pins 1 and 2.... Do you need the reference data/measurements from the SS board as well?

No, thanks for that but that has not made anything clearer except maybe to suggest the problem is elsewhere. Was trying to use my SC as a guide but the FET driver IC is completely different and the measurements also different at hos points. i was hoping to find one completely different to the rest.

[tw2005]

Re: Panisonic 42inch TCP42S30 not working!!

With those transistors, just checking if it's pins 1-5, 2-3 you're measuring. Slide below was from ny board when I was working on it.

[Hok]

Re: Panisonic 42inch TCP42S30 not working!!

Yes, and that's a cool slide

[Hok]

Re: Panisonic 42inch TCP42S30 not working!!

Is there a methodical way to go through the board by sections to narrow down where the issue may lie? Since I'm not showing a short, I wonder if that's a silly question... but had to ask.

[tw2005]

Re: Panisonic 42inch TCP42S30 not working!!

To a point but the difficulty is the manual is no good for blowing the image up. I found a 50GT30 manual from another region which must have a very similar cct design I'm using to get an idea.

Nothing popped when you powered up for the 6blink?

So all IGBTs ahve been rechecked for short, nothing there missed?

How about any diodes around the areas ofd the failed transistors, nothing shorted there?

[Hok]

Re: Panisonic 42inch TCP42S30 not working!!

nothing popped. The TV turns on like normal, screen comes up, then after 2 secs (or less) the screen goes black and 6 blink comes up. Repeats the same every time. Did check the IGBT's and they all seem to be in order. Same with the diodes. Resistors also all just under 8 Ohms, so they seem to be fine. Need to pop out for a few hours... if you have any bright ideas, i'll follow up when I return.

[tw2005]

Re: Panisonic 42inch TCP42S30 not working!!

nothing popped. The TV turns on like normal, screen comes up, then after 2 secs (or less) the screen goes black and 6 blink comes up. Repeats the same every time. Did check the IGBT's and they all seem to be in order. Same with the diodes. Resistors also all just under 8 Ohms, so they seem to be fine. Need to pop out for a few hours... if you have any bright ideas, i'll follow up when I return.

Are you saying you get a normal display for 2 secs? was the green LED lit at all?

No real ideas, still clutching to the hope we can sort it out. i'll be off by then,

[Hok]

Re: Panisonic 42inch TCP42S30 not working!!

don't recall seeing a green LED ever on this set - not sure it has one

[tw2005]

Re: Panisonic 42inch TCP42S30 not working!!

don't recall seeing a green LED ever on this set - not sure it has one

On the SN board there's a tiny LED, SS has the same. So you get a normal display for 2 sec then shutdown?

[Hok]

Re: Panisonic 42inch TCP42S30 not working!!

yes then shut down and 6 blink... i will put the board back in, hook it up, and check for the green LED if that would help.

[Hok]

Re: Panisonic 42inch TCP42S30 not working!!

tell me where on the board should I find the green LED?

[Hok]

Re: Panisonic 42inch TCP42S30 not working!!

Don't see a green led on the SN board, but I do see the SS board (green LED) - lights up for a second. Screen turns on for only a second, not 2 secs, and there is a click on the P board when it shuts itself down into SOS mode.

[Hok]

Re: Panisonic 42inch TCP42S30 not working!!

Hey I found TPSOS6 on the board.... it's nowhere near the replaced IGBT's... only problem is I don't know what to do with it

[tw2005]

Re: Panisonic 42inch TCP42S30 not working!!

Hey I found TPSOS6 on the board.... it's nowhere near the replaced IGBT's... only problem is I don't know what to do with it

I was wondering about the DG302 IGBTs. Then I read Hombre latest thread. There may be a clue in what he says because he just finished replacing the same IGBTs to get SOS6, he found Q441 had low resistance across the 2 pins but not short. He replaced that and now it works but says he has some sparkles.

Might be worth more resistance checks.

[Hombre]

Re: Panisonic 42inch TCP42S30 not working!!

Yes, at first i didn't take that as short, but tried to replace it and SOS6 was gone, tv powers up normaly

[Hok]

Re: Panisonic 42inch TCP42S30 not working!!

Thanks TW and Hombre. I checked both of the DG302's and they have similar resistance readings across the 2 pins at 46 k ohms. I assume then, that I'm encountering something a bit different.

[tw2005]

Re: Panisonic 42inch TCP42S30 not working!!

damn frustrating. So did you end up locating the little LED, be towards the centre to top section. was wondering if it's lighting momentarily like the SS.