Panasonic TX-P42ST31B 7blinks

[sienoki]

Thought id try n fix this set for a friend..common 6 IGBTs blown..bought the repair kit and also replaced IC501/IC502..Q531/501
So its an TNPA5330 SN board and after replacing the parts still 7 blinks..the 2 fets and fuse has also failed on the PSU..ive ordered them so im going to get PSU back to life before going any further with SN board..after reading all the posts on here regarding TNPA5330 thought id double check my soldering Q401-30F131 wasnt soldered correctly with the tab.

So my question is how do i test the SN for shorts..thx

[sienoki]

Re: Panasonic TX-P42ST31B 7blinks

Thought id try n fix this set for a friend..common 6 IGBTs blown..bought the repair kit and also replaced IC501/IC502..Q531/501
So its an TNPA5330 SN board and after replacing the parts still 7 blinks..the 2 fets and fuse has also failed on the PSU..ive ordered them so im going to get PSU back to life before going any further with SN board..after reading all the posts on here regarding TNPA5330 thought id double check my soldering Q401-30F131 wasnt soldered correctly with the tab.

So my question is how do i test the SN for shorts..thx

Ground lug on Sn board to white connector gives constant beep on 1 leg and OL on the other leg and thats the same with tv chassis being the ground..so the SN board is still shorted right?

[flocko]

Re: Panasonic TX-P42ST31B 7blinks

Please use the search engine for all you need to know about testing and repairing these and other Panasonic board.There are pages and pages of info on here, that I and others have posted in the past . So please help yourself

[vinceroger69]

Re: Panasonic TX-P42ST31B 7blinks

what about across just the two pins of the connector
http://alpengeist-tvrepair.blogspot....330-board.html

[sienoki]

Re: Panasonic TX-P42ST31B 7blinks

what about across just the two pins of the connector

480 1 way n OL the other in diode mode

[ReeceyBurger123]

Re: Panasonic TX-P42ST31B 7blinks

With a DMM and diode mode. Ive also had a Xcap on the input of this board short out as well after the 30f131 fets failed. 1.5uf 250v red colour near Vs input connector.

[sienoki]

Re: Panasonic TX-P42ST31B 7blinks

what about across just the two pins of the connector
http://alpengeist-tvrepair.blogspot....330-board.html

Thx vinceroger69..ive replaced all them parts from that blog except Q451..neg probe on collector n pos probe on gate i get OL so part failed also?
Should i pull that out of circuit n see if short gone..thx

[vinceroger69]

Re: Panasonic TX-P42ST31B 7blinks

ive no idea too be honest never repaired one of these boards myself but read a few threads about the repair of them not sure if that blog site lists all the faulty parts either but in the comments he has good reviews.

[Moreno83]

Re: Panasonic TX-P42ST31B 7blinks

To test the buffer boards on TNPA5330 you need to test in diode mode.

Black prope on "TPVFG" and red prope on the connectors.
Measuring for short on the white prong connector will beep shortly in 1 way and won't beep the other way if the board is "ok".

If you have bad/fake parts the board will measure ok but still can blow when power is injected.
You need to fix the power supply first and measure the voltages WITHOUT the SC board. I used R6020ANX for the PS.

It must measure 107V on start up ( blinking led ) and then jump to 215V before shutting down to 7 blinks. ( Because there is no y-sus ).

[sienoki]

Re: Panasonic TX-P42ST31B 7blinks

Thx vinceroger69..ive replaced all them parts from that blog except Q451..neg probe on collector n pos probe on gate i get OL so part failed also?
Should i pull that out of circuit n see if short gone..thx

Ive pulled the Q451-DG302 out n it reads OL on both legs with neg probe on tab?

[Moreno83]

Re: Panasonic TX-P42ST31B 7blinks

Ps TPVFG is on the top left corner of the y-sus board.

[Moreno83]

Re: Panasonic TX-P42ST31B 7blinks

DG302 is probably not shorted. If there is not worked on before only the 6 IGBT's + IC501 etc are shorted.

Black prope on tab and red on left or right leg , no beep is ok.

[sienoki]

Re: Panasonic TX-P42ST31B 7blinks

To test the buffer boards on TNPA5330 you need to test in diode mode.

Black prope on "TPVFG" and red prope on the connectors.
Measuring for short on the white prong connector will beep shortly in 1 way and won't beep the other way if the board is "ok".

If you have bad/fake parts the board will measure ok but still can blow when power is injected.
You need to fix the power supply first and measure the voltages WITHOUT the SC board. I used R6020ANX for the PS.

It must measure 107V on start up ( blinking led ) and then jump to 215V before shutting down to 7 blinks. ( Because there is no y-sus ).

I get a 5sec beep then 481 n 1sec beep then OL
IVE ordered R6015ANX for PSU are they ok?

[sienoki]

Re: Panasonic TX-P42ST31B 7blinks

Ps TPVFG is on the top left corner of the y-sus board.

TPVFG bottom left black probe on test point n ran red along all buffer connectors n no beeps so they be ok

[sienoki]

Re: Panasonic TX-P42ST31B 7blinks

DG302 is probably not shorted. If there is not worked on before only the 6 IGBT's + IC501 etc are shorted.

Black prope on tab and red on left or right leg , no beep is ok.

No beep on either leg of DG302 so thats safe to solder back on?..just need to buy some heatsink glue when repaired hopefully

[Moreno83]

Re: Panasonic TX-P42ST31B 7blinks

You mean top left TPVFG ( Between 2 buffers ). Yes , no beeps is ok.

Both sides beep is not good. Check if Q661 bottom left corner is not shorted.

Q441 / Q 451 are both ok? Check for short between 2 outer legs and tab + 2 legs.

Did you use a repair kit? If so , which one? There are a lot of fakes on eBay.

[Moreno83]

Re: Panasonic TX-P42ST31B 7blinks

Yes that DG302 will be fine. Im sure only the 6 known IGBT's have failed.

On this board originally q401 , q402 , q403 , q421 , q422 , q423 , IC502 & Q531 will fail.

If the buffers are failing the top side igbt's will read short including all diodes and DAF30A. Removing all the shorted igbt's will result in all diodes still ok so there is no need replacing them all.

Just wait for the PS parts to arrive or get a replacement Ps.

[sienoki]

Re: Panasonic TX-P42ST31B 7blinks

You mean top left TPVFG ( Between 2 buffers ). Yes , no beeps is ok.

Both sides beep is not good. Check if Q661 bottom left corner is not shorted.

Q441 / Q 451 are both ok? Check for short between 2 outer legs and tab + 2 legs.

Did you use a repair kit? If so , which one? There are a lot of fakes on eBay.

Q661 n Q441 ok cant find Q451 as yet doh..my bad the 1 under heatsink..yeah no beeps

[sienoki]

Re: Panasonic TX-P42ST31B 7blinks

You mean top left TPVFG ( Between 2 buffers ). Yes , no beeps is ok.

Both sides beep is not good. Check if Q661 bottom left corner is not shorted.

Q441 / Q 451 are both ok? Check for short between 2 outer legs and tab + 2 legs.

Did you use a repair kit? If so , which one? There are a lot of fakes on eBay.

componentalliance for 6 main IGBTs n MBTV electronics for RF1501/DAF30A..SMD transistors from M-core..n ics from chipbay_store..went with cheaper option at 1st with just the 6 IGBTs n really i should have just bought afull kit from 1 supplier cos it aint worked out cheap doh

[Moreno83]

Re: Panasonic TX-P42ST31B 7blinks

I hope you will receive good items. The 30F131 and RJP30H2A are almost all fake.

If you can wash off the logo + name with alcohol/aceton or its fading out then you probably have fakes.