Samsung PN42C450. Should Vs be shorted to GND?

[MrBerga]

Hey all. Working my way through a diagnosis. Basically if the X Main Board is plugged in with power, the TV will not boot. No sound, just repeated relays clicking.

I noticed that Va does not get shorted to ground anywhere in the TV. On the SMPS and Y Main Board, Vs has high resistance to ground (20k ohms or higher). However on X Main Board, Vs has 0 ohms resistance to the chassis ground. Vs is shorted to ground ONLY on the X Main Board.

I have a second X Main Board purchased from eBay with the same behavior. Can anyone confirm whether this is correct?

Thanks!

[tom66]

Re: Samsung PN42C450. Should Vs be shorted to GND?

Vs should not be shorted to GND.

You have found the X-main to be bad -- very common problem with this set.

Your new X-main may be bad too as it's sometimes possible for a cracked screen to damage them (if they are powered up when the Wii controller hits the TV.)