Clicking Transformer??

[shorteddiode]

Samsung LNT4069FX-XAA. Customer said the cable guy told him the cable box that was hooked up to the TV was struck by lighting. The TV when plugged in clicks a little faster than one click a second and it seems to be coming from the yellow transformer at the top center of the first photo. You can not feel the click when you touch it or the surrounding components. Both fuses on the board are good, all caps tested good with ESR meter. I cannot test voltages because they bounce all over with the clicking. If I unplug the main board it stops, but if I plug the main board back in and disconnect cables from the main board it still clicks., Any ideas??? Will a transformer click?

[tom66]

Re: Clicking Transformer??

Your username is a good start... this is a very common symptom of a shorted diode. Can also be a bad startup cap, bad controller IC or excessive load on the output.

[budm]

Re: Clicking Transformer??

Yes, it does sound like it is the start-up-shutdown mode due to fault that Tom has indicated.

[shorteddiode]

Re: Clicking Transformer??

Would the fault be in the power supply or the main board? I know ho it w to test everything but the IC controller. Is there a way to test it by resistance between pins?

[retiredcaps]

Re: Clicking Transformer??

You can not feel the click when you touch it or the surrounding components.

Everything inside the black thick line on the power board is HOT. Touching it could lead to reprecussions including serious injury, death.

[momaka]

Re: Clicking Transformer??

Would the fault be in the power supply or the main board?

You will have to test that...
With the power supply connected to the main board, check resistance between all voltage rails and ground. See if any of them appear shorted.
- If YES, note which voltage rail is shorted, and follow that voltage rail on the main board.
- In NO, then since the power supply doesn't click when disconnected from the main board, I would suspect bad start-up cap or bad output capacitor(s).