Samsung PS50C550 briefly turns on with partial white screen

[stupot1]

Hi,

I have a Samsung PS50C550 plasma that does not turn on.

The screen flashes on briefly for a split second, i have taken a video of this and managed to get the frame out that has what is shown on the screen when it powers on.

It looks like there is an issue with the left side of the screen.

Can someone help me diagnose this fault, my suspicions are that the screen is broken but if it is electronics and can be fixed that would be great.

Many thanks,

Stuart

[tom66]

Re: Samsung PS50C550 briefly turns on with partial white screen

Looks more like an X-main or control board fault.
See: https://www.badcaps.net/forum/showpo...61&postcount=2
for a test to make

[stupot1]

Re: Samsung PS50C550 briefly turns on with partial white screen

Hi Tom,

Thanks for the reply.

The TV behaves exactly the same with pins 3 and 4 shorted on the test connector shorted.

I have measured the Vs and Va voltages after turn on and these go up to the correct level but drop straight away, but these voltages stay steady at 211V and 55V with the Y-Main board ribbon cable disconnected.

[tom66]

Re: Samsung PS50C550 briefly turns on with partial white screen

It is possible you have a Y-main defect then. The best test involves an oscilloscope, but if you do not have one you can check the FETs and other devices for shorts.

[stupot1]

Re: Samsung PS50C550 briefly turns on with partial white screen

Does the test require the full TV or just the board?

I have access to an oscilloscope at work that I can try and bring home.

Can you provide details or a link to the test please.

[tom66]

Re: Samsung PS50C550 briefly turns on with partial white screen

You need to test the board as installed in the chassis.

[stupot1]

Re: Samsung PS50C550 briefly turns on with partial white screen

OK, that will be fine.

I will try and get a scope for tomorrow evening.

[tom66]

Re: Samsung PS50C550 briefly turns on with partial white screen

Make sure to get a fixed (non-switchable) 10X probe, or that the scope is rated to 400V minimum.

[stupot1]

Re: Samsung PS50C550 briefly turns on with partial white screen

Hi Tom,

I have acquired a scope with a 10x probe, the scope is a bit antiquated but a scope nonetheless.

I will be home a bit later to do the test, can you provide a link or give me some details of what I need to test.

Thanks for your help by the way.

Regards,

Stuart

[tom66]

Re: Samsung PS50C550 briefly turns on with partial white screen

You will have to provide some pictures and I can indicate the places to test.

[stupot1]

Re: Samsung PS50C550 briefly turns on with partial white screen

Hi Tom,

Sorry it took so long, here are the photos of the TV internals.

Regards,

Stu

[tom66]

Re: Samsung PS50C550 briefly turns on with partial white screen

Can you remove this board and take a picture of underneath it?
https://www.badcaps.net/forum/attach...7&d=1366286544