Re: Sony KDL46SL140 - Works when hot, doesn't work when cold

TV works great now. I cleaned the contacts just as suggested and now there is no buzzing or arcing. Thanks guys!

Re: Sony KDL46SL140 - Works when hot, doesn't work when cold

I believe I have found the problem! The board on the far left which I think is the florescent bulb driver board is definitely the problem. When the entire TV is cool but that board is hot, the TV works.

Upon examining this board I see some melted plastic pieces. I believe this is where the problem is but I don't know how to fix it yet. The plastic doesn't come off very easily to see what is under it. Attached are photos. Suggestions would be great at this point on how to fix the melted area!...

Re: Sony KDL46SL140 - Works when hot, doesn't work when cold

Tom66, sorry for being a dork but, I feel like I've proved that the PSU and main board don't have a problem because they work both hot or cold. Looking for dodgy joints on those doesn't make sense to me. Can you explain?

Re: Sony KDL46SL140 - Works when hot, doesn't work when cold

Attaching picture of back of set. The two boards that seem to be ok when hot or cold is the orange one in the center and the blue one on the bottom right....

Re: Sony KDL46SL140 - Works when hot, doesn't work when cold

There are 3 main circuit boards in this TV. I'm not an expert, but one is where the power cable is terminated to which I believe is the PSU, one is where all the AV components plug in to, and another is probably a LCD controller bank.

Today I took the TV outside to warm it up. It worked fine. I took out the PSU and AV board and put them in the freezer for 10 minutes. I brought them out and put them in the TV and it worked fine. This proves to me that neither the PSU or the AV board are the problem here....

TV: Sony Bravia KDL46SL140

If the TV is over 90 degrees warm, it works just fine, no problems.

If the TV has an ambient temperature in the 70's or 80's it shuts off during some kind of power on self test. I see the Bravia logo appear on the TV but before I get any control of the TV (within 6 seconds) the relay switches the TV off. It will stay off until I unplug it and plug it back in.

I've taken the back off and looked for swollen caps. I didn't see any obvious ones. I also used my magnifying glass to look for bad solder joints. Again I couldn't spot...