Panisonic 42inch TCP42S30 not working!!

[tw2005]

Re: Panisonic 42inch TCP42S30 not working!!

I used the flowchart from the training manual that Tom uploaded to the forums. Vsus and Vda were fine, but a short was presented for P15V. Went through the flow chart on slide 56 all the way to the bottom, the results of which indicated "replace the SC board"

So my thought was if I were to put the board back in, would it be a good test to check the P15V again - perhaps the absent of a short would indicate that we have found the fault.

As for the other transistors/diodes that are still on the board, I have tacked the legs back down - I think that they do not indicate failures, but i'm happy to check again with detailed advice. I am hoping that Glitcher's experience with the same board would give me some hope that we're almost there.

Not sure if I should test the IC and the 5-pin transistor, however if you have the time to walk me through it, I'm happy to do it.

This is interesting because SN2 is the vsus line so you said vsus tested ok, 15v shorted. none of those shorted transistors would short the 15v but would short SN2 vsus.

On the SN board near Sc20, is there a test pad labelled TP82, that's the P15V, check resistance from there to ground.

As for the 5 pin transistor, guidance in previous post in bold. see how you go with that.

[Hok]

Re: Panisonic 42inch TCP42S30 not working!!

TP82 to ground is .9 volts

see my posts at bottom of page 3 on the component testing

[tw2005]

Re: Panisonic 42inch TCP42S30 not working!!

for the 30f131's:
1) 0 volts and 0 volts
2) .008 volts and .012 volts
3) 0 volts and .005 volts
4) 0 volts and .004 volts

or did you want me to measure resistance (ohms?)

no they're stuffed, it's all the other bits and pieces i'm unsure about but now that you have a better idea of the readings, I'm happy if you are that they are now ok.

Here's the cct around that IC502. Vdd = the 15V line .

you can see the relationship between IC502, R531, Q531. What was the resistances on Q531, I'm curous.

the only tests I'd do and not sure what to expect would be resistance on pins, 1,2,7 to gnd.

[tw2005]

Re: Panisonic 42inch TCP42S30 not working!!

TP82 to ground is .9 volts

see my posts at bottom of page 3 on the component testing

That should be fine, certainly not short but i would like resistance in ohms.

[Hok]

Re: Panisonic 42inch TCP42S30 not working!!

Q531 resistance on both sets of pins is 25+ Mega Ohms
TP82 to GND 17 k Ohms

"They're stuffed" - is that Aussie for "junk"?

ic502 pin 1 to gnd .47 mega ohms, same for pin 2... pin 7 to gnd is 28.3 mega Ohms

[tw2005]

Re: Panisonic 42inch TCP42S30 not working!!

just with these
D421 reads .425 volts on both sides (from pin 1 to pin 2 and from pin 3 to pin 2)
D421 reads .373 volts on both sides (from pin 1 to pin 2 and from pin 3 to pin 2)
obviously with have a copy and paste error, but when you did this did you reverse the probes to reverse the polarity for no reading?

Should be fine as they go dead short when they fail so the readings you did have are typical.

I would say it's looking like just 4 x 30F131. SJ had the kit for $20, not sure what these would cost, china is usually cheap but take forever to arrive.

[Hok]

Re: Panisonic 42inch TCP42S30 not working!!

Right, the 2nd was D401 and reversed polarity returned 0L. I will order those components from a Canadian supplier, should be here in a couple of days. $12 for 4 of them includes shipping. I'll give you a holler once i've got them on, and thanks for all the time you've put into this and other issues on this forum

[tw2005]

Re: Panisonic 42inch TCP42S30 not working!!

Q531 resistance on both sets of pins is 25+ Mega Ohms
TP82 to GND 17 k Ohms

"They're stuffed" - is that Aussie for "junk"?

ic502 pin 1 to gnd .47 mega ohms, same for pin 2... pin 7 to gnd is 28.3 mega Ohms

nothing looks shorted there so i would say ok.

Yep or buggered is another term but old fashioned. Slang can be interesting between different parts of the globe.

pissed is one I found interesting, we use it to say we're drunk, however stumbling around telling someone from the US the same and they think pissed off and looking for a fight.

We had a world expo back in 88, it was funny we were having a ball saying how pissed we were, and the facial expressons from the Americans there were quite serious and concerned. We worked it out thank god and had a good laugh at the miscommunication.

[tw2005]

Re: Panisonic 42inch TCP42S30 not working!!

Right, the 2nd was D401 and reversed polarity returned 0L. I will order those components from a Canadian supplier, should be here in a couple of days. $12 for 4 of them includes shipping. I'll give you a holler once i've got them on, and thanks for all the time you've put into this and other issues on this forum

Sounds good. At least we've tried to be thorough about it. I've been on the wrong end of assuming some parts are ok and powered a board up, was a nightmare to get back to life after that with all the extra damage.

[Glitcher]

Re: Panisonic 42inch TCP42S30 not working!!

This was the one I bought on ebay.
http://www.ebay.com/itm/261410038970...84.m1439.l2649
buying 2 sets which is 4 pieces costs about 20$ + 2.50$ shipping. Usually takes 2-4 days to deliver in the US

Or
http://www.ebay.com/itm/5Pcs-30F131-...item5402153b7c
$7 from china for 5 pieces, it usually takes 2 weeks to deliver to the US.

But Sometimes I don't like waiting so long for parts from china too.

Never bought parts from Canada before, let us know how long it actually took to arrive. Maybe I'll try buying from there too if it doesn't take too long.

[Hok]

Re: Panisonic 42inch TCP42S30 not working!!

Will do, and thank you for your encouragement... I have some hope that we may get this set working without tossing unnecessary waste in the landfill.

[Hok]

Re: Panisonic 42inch TCP42S30 not working!!

BTW TW, as you've figured out, it was the VSUS that was shorted and not the P15V - I was tired last night and forgot what steps I had taken to narrow down the problem before removing the board.

[Hok]

Re: Panisonic 42inch TCP42S30 not working!!

The new 30F131's came today and I installed them on the board.

Put everything back together and VSUS short was gone.

Turned on the TV to see 6 Blinks. (This is a first, at least the 14 blinks is gone.)

Checked all connections and tried again. 6 Blinks.

Went to the troubleshooting flowchart on slide 67 of the TM.
Removed connectors SC20 from SC board and C20 from the C2 board.
TV turns on and off just fine, (black screen,) indicating "Replace the SC Board" per TM.

Slide 66 shows the causes of 6 blinks.

Here's the question: Do I continue to troubleshoot the SC board or do I buy a new SC board?

TW, if you have the time I would continue to troubleshoot it.

Thanks.

[Hok]

Re: Panisonic 42inch TCP42S30 not working!!

Quick update: Screen flashes when powered on... also get 5.04 volts on the 5 volts line and 15.8 volts for just an instant on the 15V (SC board) the voltage reading dies off when the 2nd click is heard from the P board. (same time the screen goes dark)

6 blinks winking at me with a sardonic smile

VSUS measured 215V for just an instant as well (at the P board)

[tw2005]

Re: Panisonic 42inch TCP42S30 not working!!

i don't think I could get you much further. This is why the kit may have been handy for the 20% that needed the FET driver and Q531. Even then there's no certainty.

I know on my boards the FET driver had died but the some of the other parts survived, probably good practice to replace it in case but don't know how you'll get one or if it will solve it.

You can't send the board for repair either, most won't touch it if attempted repair but Modus is the only one that I read feedback on.

[Hok]

Re: Panisonic 42inch TCP42S30 not working!!

buggered or stuffed

over here we'd say I'm up a creek without a paddle.

[tw2005]

Re: Panisonic 42inch TCP42S30 not working!!

buggered or stuffed

over here we'd say I'm up a creek without a paddle.

That too, but not drowning.

[tw2005]

Re: Panisonic 42inch TCP42S30 not working!!

I got an idea. I think I missed something with your readings, 25Meg ohms Q531, IC502 28.3 megohms.

There's probably another FET driver on the board. Since they say some need those replaced I'm thinking this could be the issue but i'd like to see if we can compare the cct to the other drive cct.

It may not be a loss yet. Don't know why i did not click, 25Meg is very high probably as good as open cct.

Go to the same IC and transistor set at IC501, Q501 and perform the same resistance checks as done in posts 63 & 65

There's 5 of those IC on the SS and 5 on the SN.

IC16501
IC16502
IC16521
IC16522
IC16684

We could get multiple comparisons and that should give us a good clue what is normal. I'm hoping all of these come up very close.

SN
IC522,Q551
IC521,Q521
IC501,Q501


SS,

IC131, Q141
IC132,Q161
IC151,Q055
IC152, Q056

[tw2005]

Re: Panisonic 42inch TCP42S30 not working!!

https://www.encompassparts.com/item/...0ZBZ0001822/Ic
https://www.encompassparts.com/item/...001/Transistor

https://www.partstore.com/SearchResu...=PMN&x=25&y=12
https://www.partstore.com/SearchResu...p=PMN&x=20&y=7

[Hok]

Re: Panisonic 42inch TCP42S30 not working!!

working on it now. There's a slight frame of reference issue.... If pin 1 is on the upper left side.... The only identifying mark on the ic is a small dot, which is either on the upper left side or the lower right side... Didn't even occur to me that I may be testing the wrong pins on the IC502... How can I adjust my frame of reference for the pin numbers?

Actually: IC502 has no numbers imprinted on the surface, just the small dot. However, IC501 and IC684 each have the following numbers imprinted on it... (the O is the dot)

D 6
9 3
ONS

(The pins run horizontally to the numbers, across the top and the bottom)