Re: Panasonic tc-p42s30 TNPA5349 SN board
Unfortunately I haven't fix it yet. If I did, I would let you know... I've been waited the parts too long...
No, on both boards the green LED is on but on SS board the LED is brighter. Otherwise on SN board is almost unvisible.
Before power on I checked all soldering, especially tabs on diodes and transistors.
I've checked all new parts before putting in and they had no short.
I will change the parts which you suggested.
Thx for your help.
PinkySa
Member
Last Activity: 08-17-2018, 07:27 AM
Joined: 02-17-2015
Location: Sarajevo
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Re: Panasonic tc-p42s30 TNPA5349 SN board
I've changed both DG302, IC501 and Q531 also all 4 IGBTs. As you suggested I put little heat. Now my board is not shorted after powered on but I got 6 blinks code. The green LED on SN board turns a bit on after switching on. Any idea what could be wrong now? ThxLeave a comment:
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Re: Panasonic tc-p42s30 TNPA5349 SN board
I checked resistance on both DG302, between Collector and Emiter I have 10.5Kohm, between Gate and Collector I have OL.
Also checked Q501, IC501 and IC684 and there is no short.
Flocko, why you changed Q531 and IC502 on a.m. board? They were short, or just in case?Leave a comment:
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Re: Panasonic tc-p42s30 TNPA5349 SN board
Yes, you are right. After my second failure to repair, I had short on Q501 and IC501 which I changed. I'm checking all parts before turn the tv on. I'll double check them again.Leave a comment:
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Re: Panasonic tc-p42s30 TNPA5349 SN board
Thx.
I'll check them and compare with the new DG302.Leave a comment:
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Re: Panasonic tc-p42s30 TNPA5349 SN board
Thx Flocko for response...
Yes, I replaced them all with a new parts.
I tested them after I've fitted them, also tested the soldering physically as well as electronically. After all, tested on SN2 and was no short.
I couldn't find on this topic any explanation how to test DG302, just for near by IC502 and Q531. Pls, could you provide quick info?Leave a comment:
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Re: Panasonic tc-p42s30 TNPA5349 SN board
The 4 MOSFETs are dead.
Could it be that I'm using cheap parts? From where you are purchasing your parts?Leave a comment:
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Re: Panasonic tc-p42s30 TNPA5349 SN board
Hi guys again,
After received the new components, I replaced all listed above (suggested by Flocko). Put back sn board into tv and I got short on SN2 again after switching tv on
All panel ribbons were connected, screws tighten well.
Now I disconnected sn2 and sn20 and turned tv again, it blinks 8 times. Green led on ss board lights on for short period. No short on Vsus on SS board. On sn2 connector I got cca 210V.
What is killing my SN board?
Last edited by PinkySa; 09-02-2015, 05:48 PM.Leave a comment:
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Re: Panasonic tc-p42s30 TNPA5349 SN board
I'll remember that next time
Leave a comment:
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Re: Panasonic tc-p42s30 TNPA5349 SN board
Thx tw2005. Yes, I referred to those diodes. So it seems that is ok.
I'll replace bad MOSFETs and put other components back together and try again.
Somewhere on this forum I found that good source for components is ebay->utsource, still true? I already ordered from them MOSFETs which I have intent to replace.
Do you guys prefer contact pads (or how they call in english) between screws and board.Leave a comment:
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Re: Panasonic tc-p42s30 TNPA5349 SN board
Hmm, I was misleading all the time.
Yes, you are right, the legs of a.m. diodes are Anode and they are common. I also checked the datasheet of those diodes. I also checked diodes which I removed, and they are ok.
Now I understood your sentences:
It seems that only 4 IGBTs are dead.
I'm still concerned about diodes near buffer ICs (D4652, D4654, D4852, D4853), is it ok to show short between pins on the board, after removing (two of them I removed)?...Leave a comment:
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Re: Panasonic tc-p42s30 TNPA5349 SN board
Thx for your response...
Yes, 00.300 on 20M scale.
Any other idea what should I check?
I don't think that is ok to have short on board where a.m. components were.
[I]I still have short on the board where D461, D481, D421, D401, D641, D642 legs were. [/I]Re: Panasonic tc-p42s30 TNPA5349 SN board
Thx for your response...
Yes, 00.300 on 20M scale.
Any other idea what should I check?
I don't think that is ok to have short on board where a.m. components were.
[I]I still haveLeave a comment:
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Re: Panasonic tc-p42s30 TNPA5349 SN board
It seems that buffer ICs are ok. No low ohm reading between TPVFG and connector pins. the meter is set to 200ohm.
Tested Q531 and IC502 and have cca 300Kohm on some pins on both components, other pins show several MOhms.
I also found out that Emiter pins on board of Q421/2 have short with gnd.
Remark that Q421/2 are removed.
How to test IC/Q521 and IC522, Q551? The same 20M test? If is so, some pins show 0ohm.Leave a comment:
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Re: Panasonic tc-p42s30 TNPA5349 SN board
Thx a lot, I'll test asap, and provide you with information...Last edited by PinkySa; 08-02-2015, 07:10 AM.Leave a comment:
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Re: Panasonic tc-p42s30 TNPA5349 SN board
Hi to all forum members, especially to tw2005, your posts helped me a lot.
I had the issue with short pins on SN2 connector. Some MOSFETs and diodes were short.
Ordered, replaced and the TV was working for a couple of minutes. Then puff and SN2 is shorted again. Probably bad soldering of the new components or loose screws.
Now I have the situation that a lot of components are short, the same as by Ponomo1:
4 MOSFETs (Q401, Q402, Q421, Q422)
2 RF20 diodes (D641 and D642)
3 RF1501 diodes (D461,D481,D401)...Leave a comment:
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