samsung ps42c450b1w clicking

[Manddave]

Hi there
I have a samsung ps42c450b1w plasma tv
It seems to have the clicking relay on the psu and will not turn on.
The psu was changed but no luck.
When the main ysus is unhooked the tv powers up but no pic
When just the xsus is unhooked I get the same clicking on the power board and nothing.
There are no bad caps visible.
Can you help please

Thx

[Manddave]

Re: samsung ps42c450b1w clicking

Anyone help plz

[Manddave]

Re: samsung ps42c450b1w clicking

Anyone help with identifying which board is at fault as I have limited experience
thanks

[tom66]

Re: samsung ps42c450b1w clicking

Most likely Y-main -- can you post some pictures of it? Have you checked VS voltage?
When replacing these boards it's sometimes needed and often a good idea to replace both X- and Y-main at same time, due to how they chain together, damage on one can damage the other.

[Manddave]

Re: samsung ps42c450b1w clicking

Hi thanks for the reply
I will have chance to look at this better tomorrow and get some pics
I know it's not the power board for certain
Can you tell me what voltage I need to check
Thanks

[tom66]

Re: samsung ps42c450b1w clicking

Vs is marked on the power board, it should be around 200V.

[Manddave]

Re: samsung ps42c450b1w clicking

The vs on the power board to the ysus looks ok
The vs on the ysus to the x is virtually nothing.

[tom66]

Re: samsung ps42c450b1w clicking

Are you sure? They are directly connected to each other.

[Manddave]

Re: samsung ps42c450b1w clicking

How do you mean?
The vs pin on the psu is showing voltage.
But the vs pin on the ysus that goes to the x board shows nothing

[tom66]

Re: samsung ps42c450b1w clicking

From what I remember there is a direct circuit trace between the Vs in and out on the Y-main.

[Manddave]

Re: samsung ps42c450b1w clicking

Ok my bad sorry I am getting voltage to the vs but losing it on and off with clicking psu

[Manddave]

Re: samsung ps42c450b1w clicking

Here are some pics
When ysus is unhooked the tv goes into its normal start up.
when its plugged in again i get 5 or 6 clicks from the psu and then nothing.

[capkid]

Re: samsung ps42c450b1w clicking

This may be one of those Samsungs in which you can test for shorts in the components on the heat sinks and quickly find your problem boards: https://www.badcaps.net/forum/showth...t=ns-50p650a11

[Manddave]

Re: samsung ps42c450b1w clicking

Changed out most of the boards on this tv and still the same
Anyone any ideas please
Would the buffers cause this problem?

[Manddave]

Re: samsung ps42c450b1w clicking

Any ideas what this could be please

[Ltank]

Re: samsung ps42c450b1w clicking

So You removed the P.S. plug to Yand X board and it continued to cycle on/off? Remove the connector at P.S. from the main board. Does it still cycle on/off? If yes then its the P.S. No its the Logic board. according to the Tranining Module page 46

[freakaftr8]

Re: samsung ps42c450b1w clicking

Sounds like a logic board issue, arethee any leds lit up on the logic board when its power cycling? check tthe white rectangular ceramic fuse on the logic board to see if its open.

[Manddave]

Re: samsung ps42c450b1w clicking

Led on logic board lights up when cycling. When main ysus is unhooked it starts up and displays nothing
Also when logic board is unhooked from ps it goes through start up.
If I unhook main board then it does nothing.
Could I have been sold a bad psu?
Can anyone tell me how to test psu
Thx

[Manddave]

Re: samsung ps42c450b1w clicking

completely disconnected the logic board from everything and the tv starts up with no picture
when the logic board is connected to ps again it starts the cycling.
Everytime it clicks the led on the logic board lights up. it does this a few times and shuts off.

[Manddave]

Re: samsung ps42c450b1w clicking

Can anyone say if this is definitely the logic board. Due to it being replaced with a 2nd hand one