LN52A750R1F, Tcon causing set to click on/off once warm.

[johnboy1313]

I bought this set about six months ago. I put a used Tcon in it and sold it to a friend. Shortly after, it started blacking out every so often. It eventually got to the point that it wasn't watchable. I gave him a different TV yesterday and brought this one back home. After a few minutes, the picture blacks out, followed by the set cycling on/off until you unplug it. When it cycles on, the full chime plays but when it comes time to fire the backlights, it cycles off and starts over. I determined that unplugging the tcon would stop the cycling and would allow the set to come on and stay on. With the tcon connected but the LCD disconnected, the set still cycles. I feel this rules out the LCD. I recapped the PSU to be sure it wasn't caused by bad 16V 1000uf caps being loaded down. It still cycles. The tcon doesn't feel overly hot. I'm going to go over it for cracked solder joints this morning. Is there something else I should inspect?

[tom66]

Re: LN52A750R1F, Tcon causing set to click on/off once warm.

I had a 40" B650 with a similar symptom, t-con shorted causing set to cycle. Never had it occur while running, that set refused to boot entirely.

[johnboy1313]

Re: LN52A750R1F, Tcon causing set to click on/off once warm.

That's what's making me suspect a solder joint.

[tom66]

Re: LN52A750R1F, Tcon causing set to click on/off once warm.

Maybe worth checking 13V rail whilst set is running, see if it drops under load. Could also try hooking a car brake light to the 13V rail to load it down, simulating a T-con board load.