Samsung 42in Plasma shutting off

[bjorkson]

I have a problem with my 42in Samsung Plasma model PN42A450P1d, I can turn on and watched the tv 10-15 mins sometime, and other time just 2 to 5 mins before it shuts off, was wondering if it could be a power supply issue or X/Y/Z sustain board, any help is appreciated if anyone have encounter this issue.

[tom66]

Re: Samsung 42in Plasma shutting off

Do you have a digital multimeter?

Common issue with this chassis is cold solder joints on the PSU causing intermittent power.

[bjorkson]

Re: Samsung 42in Plasma shutting off

Yes, I do. I tried to looked at the wire plugs, but didn't see any voltage for me to check the output voltage. I'm a newbie at this, so, any help is appreciated.

[tom66]

Re: Samsung 42in Plasma shutting off

Pictures of the TV's boards would help us help you.

[bjorkson]

Re: Samsung 42in Plasma shutting off

OK, I'm at work right now, will take some pics of the PSU board both front and back and upload it tonight. Thanks for all your help Tom!

[bjorkson]

Re: Samsung 42in Plasma shutting off

Here's the pics, for the PSU, x and y board also. I also took a close pic of the back of the PSU board, would you consider this a cold soldier joint?

[tom66]

Re: Samsung 42in Plasma shutting off

We NEED bigger pictures to work with. I don't have these boards in front of me.

[bjorkson]

Re: Samsung 42in Plasma shutting off

Oh, sorry. I tried to take some, but don't have a camera, and took that on my camera phone. I took the PSU board out last night, look on th eback and I think there is a couple of solder joint I think is cold, but don't know. Can you post a pic of what a cold solder joint looks like?

[tom66]

Re: Samsung 42in Plasma shutting off

https://www.google.co.uk/search?q=co...Aefm4QSZjID4BA

Mainly around the larger power transistors.

[bjorkson]

Re: Samsung 42in Plasma shutting off

Yes, I notice that also, there were some solder joints around the transistor that I saw holes on it. So, what I did was check all of them and just resolder it. Seem like the TV is up working for now. I had it on for more than 1 hr today, didn't shut off. Keeping my finger cross to see if that did it. Will report back if the problem reoccurred. Thanks for all your help.

[bjorkson]

Re: Samsung 42in Plasma shutting off

Update on my TV...I left the back cover off, turn the tv on for more than 2 hrs, works fine, does not shut off. So, I thought I fixed the problem. Put the back cover back on, turn the TV on, shuts off after 15 mins. I suspect one of the boards is probably too hot, no circulation causing the board to fail. You think this is caused by the PSU board?

[tom66]

Re: Samsung 42in Plasma shutting off

I would try heating parts with a hairdryer to see if you can make it shut down quicker.

[bjorkson]

Re: Samsung 42in Plasma shutting off

Let me try this tonight and report back. So, if I use a hairdryer and blow it towards the heatsink on the power supply, once it does shut off. We can suspect that the PSU board is bad?

[tom66]

Re: Samsung 42in Plasma shutting off

Yes, and indeed, we can also locate what part on the PSU is bad.

[bjorkson]

Re: Samsung 42in Plasma shutting off

so, if we do locate a bad heatsink, what is the cause/fix?

[tom66]

Re: Samsung 42in Plasma shutting off

Often solder joint or bad capacitor.

[bjorkson]

Re: Samsung 42in Plasma shutting off

OK, I finally had time last night to do some more testing (been busy working and family). Use a blow dryer to try to shut down the PSU board, aim at the heat sink for a good 10 mins, fail to shut off. I also try the X and Y board heatsink, fail to shut down. So, I put the cover back on and see if the trap heat would shut the TV off. Had it on for a good hr, never did shut off. I will watch more TV tonight and see if it does shut off.

[bjorkson]

Re: Samsung 42in Plasma shutting off

Just wanted to let you guys know, I fix the 42in Plasma TV, I replaced the PSU board, and that took care of the issue. All running good now. Thanks for everyone's help. I'm tackling another TV right now. 50in Samsung Plasma, but I think I know the issue, has sound but no picture. Have to look around for a Y main and both upper and lower Y buffer board.