Panasonic TH-50xp80u power supply

[tom66]

Re: Panasonic TH-50xp80u power supply

I downloaded the manual for the px80ua which is what I have. I have checked every voltage on every board test point. They are all dead on. I still just have a blank screen with no pic or sound and no on screen display for menus. I have noticed if it is left on for a while the tv cycles itself off then on. Sometimes off and I have to turn it back on.

Is this an SS board problem.

Any suggestions at all. When I did the SS board seperation test I at least had snow on the screen. lol.

Could be a bad control logic board. I'm grasping at straws here. Without a scope, very difficult to diagnose things like the LVDS connector.

[tmedley]

Re: Panasonic TH-50xp80u power supply

After looking this thing over and changing the A board with only minor improvements I have begun to wonder if it is possible that the replacement A board is with out its firmware. It acts as though the tv wants to operate properly but doesn't have any On Screen Display at all. Is it possible the OSD is part of the firmware? Can you download the firmware for this tv still?

[tom66]

Re: Panasonic TH-50xp80u power supply

After looking this thing over and changing the A board with only minor improvements I have begun to wonder if it is possible that the replacement A board is with out its firmware. It acts as though the tv wants to operate properly but doesn't have any On Screen Display at all. Is it possible the OSD is part of the firmware? Can you download the firmware for this tv still?

I'd imagine only Panasonic have the firmware.

It sounds like you have an incorrect board and it doesn't like the chassis it is in. It may be possible to reset or change the board model # using the remote control, have you checked the service manual?

[strykerakamack]

Re: Panasonic TH-50xp80u power supply

Hi
Ive got the same problem with my 50 "
I need the 2 nichicon caps
the 440uf and the 1900uf
Ive looked all over ,found the 440 on the ebay
but no luck on the 1900 .
Is there something else I could put in that would work ?
Or know where I could get one from .
Thanks

[tom66]

Re: Panasonic TH-50xp80u power supply

Hi
Ive got the same problem with my 50 "
I need the 2 nichicon caps
the 440uf and the 1900uf
Ive looked all over ,found the 440 on the ebay
but no luck on the 1900 .
Is there something else I could put in that would work ?
Or know where I could get one from .
Thanks

You could probably use 1800 or 2200.

Those are Vs caps - they rarely fail - why do you need to replace them?

[strykerakamack]

Re: Panasonic TH-50xp80u power supply

both are bulged out on top and both ceramic fuses are blown .
TV went POP and main circuit breaker tripped but not the surge proector .
Not sure if main tripped cause of TV or TV blew due to circuit being tripped .
I cant find any 220v caps does that matter for the 1900u if i use a diff capacity for uf ?

before opening up tv was completely dead, no leds no sign of life remote didnt do a thing ,nor power button .
hope this helps
Thanks

[selldoor]

Re: Panasonic TH-50xp80u power supply

Ok Just a couple of things

"Ive got the same problem with my 50 ""

Same problem as who/what there are two problems running on here
and i dont think either of them starts as

"before opening up tv was completely dead, no leds no sign of life remote didnt do a thing ,nor power button ."

Secondly there are references to two boards - which one do you have.
Can you post pictures of the board, front and back and close up of connectors, (max resolution 2000x2000 and 2MB) using the manage attachments button, which is found by clicking "go advanced" under quick reply.

Please do not post inline and offsite as they slow down the loading of pages.

Examples of what is needed
https://www.badcaps.net/forum/attach...1&d=1290283049

https://www.badcaps.net/forum/attach...7&d=1280167246

Please also post close ups of the capacitors so we can see the bulge.

[tom66]

Re: Panasonic TH-50xp80u power supply

both are bulged out on top and both ceramic fuses are blown .
TV went POP and main circuit breaker tripped but not the surge proector .
Not sure if main tripped cause of TV or TV blew due to circuit being tripped .
I cant find any 220v caps does that matter for the 1900u if i use a diff capacity for uf ?

before opening up tv was completely dead, no leds no sign of life remote didnt do a thing ,nor power button .
hope this helps
Thanks

Wow. Okay, never heard of a Panasonic doing that, though I have seen on this forum a Hitachi that did so... Anyway...

Unplug both SC and SS boards - the main power connector (thick leads) and the control connector (15 or so thin leads, on bottom of board usually.)

Power up TV, try and get it to make sound if possible, check fans are running.

Set meter to 500, 600 or 1000V DC range (two horizontal bars, one broken into three parts, usually). Probe the connector you should measure around 190 - 210 VDC.

You can use 250VDC caps to replace those caps. Higher voltage is fine; the rating is only the maximum voltage the cap can withstand safely.

Next turn it off and unplug mains power. Plug in the SC board, both power and control. (SC connects to buffers, left hand side from back of TV I think.) Does it power up? Picture may be purple/dim - this is normal when only SC is connected. If it does not power up with SC unplug it, problem is with SC board. If it does power up keep SC plugged in.

Then do the same procedure for SS if TV does not power up problem is with SS.

[strykerakamack]

Re: Panasonic TH-50xp80u power supply

Ok
Here are the pics from the board that I removed
I've removed the fuses already .
On the Big caps Im not sure you can still see
but I sorta pushed em flat already but they were up about a 32nd compared to the small caps ,whereas the small caps are perfectly flat across
the + etched into top was pushed up on both big ones .

Thanks

[selldoor]

Re: Panasonic TH-50xp80u power supply

I have to go out today, but just as a quick starter did you check the little round red barrel fuse next to the copperwound bobbin in pic 5.
What is the round white component next to it- What is its board description

[strykerakamack]

Re: Panasonic TH-50xp80u power supply

Didnt even realize that was a fuse .
will give it a test
the white item directly right of the RED fuse looks to be an LED

[selldoor]

Re: Panasonic TH-50xp80u power supply

The main pictures are not really clear enough - I dont know why perhaps too small
need to be as near to 2mb as you can get. Also has focussed on the end of the
components so the board is v difficult to read.
There are two black/grey boxes -top pic 5 are they fuses as well - I think I read
5a 250v and fuse symbol on back of board cant see what it says on the front so struggling - can you decide what they are or produce a close up . The one of the LED is great. Need a better shot of the back of the board


Correction -they are not fuses - how many did you remove? if two please check
under the heat sink for a third. not sure where it should be on your board

[YuCrew]

Re: Panasonic TH-50xp80u power supply

tmedley: did you ever resolve your power supply issue?

[YuCrew]

Re: Panasonic TH-50xp80u power supply

Anyone know if I could replace the buldging 1900 uf cap with a computer grade 1900 uf cap? I realize the size might be a problem but I think I could attach leads to the computer grade cap, remove the old cap and solder leads to the board. I'd have to find a cool spot to mount the capacitor since I can't find 105C temp rated computer grade cap. Thanks

[tvtimmy]

Re: Panasonic TH-50xp80u power supply

Yes, you can do that. Glue it down or zip tie it to something. Dont mix up the neg & pos leads.

[YuCrew]

Re: Panasonic TH-50xp80u power supply

I have just replaced the A board in 50" plasma with almost all the same issues here (red led on, not blinking, relays click, all PS voltages correct, backlight on, no audio or pic). The set is working beautifully with the repaired A board but I would appreciate some expert advice on the power supply.

The 1900uf 220V Power supply capacitor is definitely bulging on the top (see picture). Should I leave it alone until it fails or remove the 1900uf cap and replace it with TWO 1,000 uf, 250V caps? While I am very skilled with soldering components and can easily do this, what do the experts recommend .... wait until failure (concerned other damage could occur then?) or replace now?

THANK YOU for any and all advise.

[dick_barton]

Re: Panasonic TH-50xp80u power supply

I would not wait for a failure because it's only a matter of time and may well take other components down with it when it occurs.

[tw2005]

Re: Panasonic TH-50xp80u power supply

I have just replaced the A board in 50" plasma with almost all the same issues here (red led on, not blinking, relays click, all PS voltages correct, backlight on, no audio or pic). The set is working beautifully with the repaired A board but I would appreciate some expert advice on the power supply.

The 1900uf 220V Power supply capacitor is definitely bulging on the top (see picture). Should I leave it alone until it fails or remove the 1900uf cap and replace it with TWO 1,000 uf, 250V caps? While I am very skilled with soldering components and can easily do this, what do the experts recommend .... wait until failure (concerned other damage could occur then?) or replace now?

THANK YOU for any and all advise.

I'm not sure if I'd consider that a bulge, you'll find that type or size of cap on these boards all have a slightly raised top but no harm in replacing it given the age of this model

[YuCrew]

Re: Panasonic TH-50xp80u power supply

My solution to the bulging 1900 uf power supply capacitor is here.

https://www.youtube.com/watch?v=cUDqYqjLtvI

Works great!