Panasonic TH-P50X20

[tw2005]

Re: Panasonic TH-P50X20

i get all mine from UTSOURCE in China, slow shipping unless you express but fixed about 8 boards , no prob and all had RJP63F3A. Don't know a sub offhand sorry. Got my own problems to sort just stuffed up trying a sub!

[MOSFET606]

Re: Panasonic TH-P50X20

Yea, thats where all these Renesas parts seem to be from, and shipping form mouser was only 7.99, says $30 at first but ebay has them for like $4 with shipping i think, in USA

[Neelix]

Re: Panasonic TH-P50X20

Took long time to get all the parts, but the TV is finally working now. Thanks again tw2005 for all your help!

I replaced IC16773, Q16701, Q16702, Q16818, Q16661, Q16541, D16451, D16481 and the reistances measured correctly afterwards, but I still got 7 blinks. My first thought was that the parts I replaced blew up again, but they all measured good still which was a relief. So while the TV was starting up, I measured VAD and it was -190V which is what it's suppose to be, but VAD then started dropping and eventually the TV would switch off with 7 blinks. The same thing happened with VSUS. I also measured VSCN, but could not get a stable voltage reading. That was strange to me because at the start of the repair, although wrong because VAD was wrong, I at least got a stable voltage reading for VSCN. I measured the resistances around VSCN generator IC16786 and they were wrong. I then replaced IC16786 and the resistances was correct again. I pressed the power button and voila, he TV switched on with no 7 blinks and all the voltages measured correct and stable

[tw2005]

Re: Panasonic TH-P50X20

Took long time to get all the parts, but the TV is finally working now. Thanks again tw2005 for all your help!

I replaced IC16773, Q16701, Q16702, Q16818, Q16661, Q16541, D16451, D16481 and the reistances measured correctly afterwards, but I still got 7 blinks. My first thought was that the parts I replaced blew up again, but they all measured good still which was a relief. So while the TV was starting up, I measured VAD and it was -190V which is what it's suppose to be, but VAD then started dropping and eventually the TV would switch off with 7 blinks. The same thing happened with VSUS. I also measured VSCN, but could not get a stable voltage reading. That was strange to me because at the start of the repair, although wrong because VAD was wrong, I at least got a stable voltage reading for VSCN. I measured the resistances around VSCN generator IC16786 and they were wrong. I then replaced IC16786 and the resistances was correct again. I pressed the power button and voila, he TV switched on with no 7 blinks and all the voltages measured correct and stable

replacing the IPD, that's a new one. So for info, did that come from UTSOURCE or where did you get that IC from.

[Neelix]

Re: Panasonic TH-P50X20

IC16786 I got from a scrap SC board that I had, but I looked on UTSOURCE now and the IC can be ordered from them:

http://www.utsource.net/search.aspx?...s=MIP3910MSSCF

[tw2005]

Re: Panasonic TH-P50X20

IC16786 I got from a scrap SC board that I had, but I looked on UTSOURCE now and the IC can be ordered from them:

http://www.utsource.net/search.aspx?...s=MIP3910MSSCF

yeah, I'm just amazed that it was part of the problem and you figured it out. Any clues on what to look out for next time?

[MOSFET606]

Re: Panasonic TH-P50X20

Well I replaced D441, D451 was fine, and an IGBT, but im measuring shorts across all the IGBTs, Emitter to collector... like 1ohm... The new has the same characteristics unless i bought a blown on from some


Is the collector to emitter suppose to be 1 ohm? Something doesnt seem right, and the new measures the same..

This is on the SC board...

[MOSFET606]

Re: Panasonic TH-P50X20

Forgot to mention i have the service manual, and the resistance check sequence... nothing seems to be bad.

What i have, is when i turn the tv, on with everything is connected... relays click/ energize, shut off... then on next power button press, just the green light turns on then off...

If i disconnect the SC board... the Relays will fire for each power button press..

Before i replaced D441... with SC board.. the relays would fire every time.. with all boards connected...

Till after the 3rd, wait 15 mins to try again or unplug power and wait 10 secs...

And the 13v audio power is also missing..

[MOSFET606]

Re: Panasonic TH-P50X20

IC 771, across the pins to showed, i get 18ohms both lead directions

[MOSFET606]

Re: Panasonic TH-P50X20

I figured im just going to buy a new SC board, for <$40....

Then the only problem i have, is the 13v Audio power not being present on the main board, with the hdmi inputs...

I thought it wa kind of ironic and idiotic that the TV will goto into protection mode if it doesnt have the 13v Audio Power...

I poked around but can't seem to find the issue...

Does anyone know what components commonly fail, for the 13V Audio Power?

[tw2005]

Re: Panasonic TH-P50X20

I figured im just going to buy a new SC board, for <$40....

Then the only problem i have, is the 13v Audio power not being present on the main board, with the hdmi inputs...

I thought it wa kind of ironic and idiotic that the TV will goto into protection mode if it doesnt have the 13v Audio Power...

I poked around but can't seem to find the issue...

Does anyone know what components commonly fail, for the 13V Audio Power?

Is it a Panasonic TV you've got or a Sanyo with panasonic panel?

Sounds like you may have purchased a bad board from some

If you have dead shorts across the IGBTs. I assume it's the transistors and not the diodes you are measuring(Q locations)

[MOSFET606]

Re: Panasonic TH-P50X20

I'm measuring across the transistors..

Haven't bought a board, but probably will, i bought an IGBT that looks shorted..

Across pin Emitter and collector pin... The diode packages, think their shotkey or some double diode variant... appear to be fine.

I de-soldered the pins to try and isolate the short.... but its alot of shorts by the looks of it... pretty much all the same you've replaced on that SC board you did... Q6xxs, etc...

I did goto school for electronics so i know a bit more then the basics... but lack the practice with troubleshooting random circuits with no schematics... or references.

Anyways... Giving up on the SC board.. what it will cost in components i can get a used working one instead.

Just need to figure out the missing 13v audio power

Its a Panasonic inside a sanyo chassis... same boards for the most part

[tw2005]

Re: Panasonic TH-P50X20

I'm measuring across the transistors..

Haven't bought a board, but probably will, i bought an IGBT that looks shorted..

Across pin Emitter and collector pin... The diode packages, think their shotkey or some double diode variant... appear to be fine.

I de-soldered the pins to try and isolate the short.... but its alot of shorts by the looks of it... pretty much all the same you've replaced on that SC board you did... Q6xxs, etc...

I did goto school for electronics so i know a bit more then the basics... but lack the practice with troubleshooting random circuits with no schematics... or references.

Anyways... Giving up on the SC board.. what it will cost in components i can get a used working one instead.

Just need to figure out the missing 13v audio power

Its a Panasonic inside a sanyo chassis... same boards for the most part

yeah, if they're freely available and cheap enough would be easier. I've had fun restoring the ones I've had. Does sound like it's along the same lines as the boards I've done if IC771 is shorted which implies IC773 will be bad and other small stuff.

Can't help with the 13V audio, not sure if the Norcal youtube video would help but I know it talks about 3 attempts then the TV locks out due to a power fail

[Neelix]

Re: Panasonic TH-P50X20

yeah, I'm just amazed that it was part of the problem and you figured it out. Any clues on what to look out for next time?

If still getting 7 blinks after replacing all the faulty parts, then checking the major test points(VSUS, VAD, VSCN, etc.) to see if the voltages are correct, is the only tip I can really think of at the moment