LG 50PZ550 plasma help with diagnostics

[diif]

Re: LG 50PZ550 plasma help with diagnostics

Too hot and you have the risk of damage. I think I've got my rework machine set for 245c max. Do an image search for reflow profiles so give you an idea of what you are aiming for.

[dannythefixer]

Re: LG 50PZ550 plasma help with diagnostics

Thanks for all of the help. I tried reflowing the main BGA chip using the recommended flux, temp sensor, and tried to follow one of the reflow curves that came with the flux (one of the higher ones that maxed out at about 245C), and at first I thought I had been victorious ... TV booted up properly 9 times in a row, but on the 10th attempt it was back to its old tricks. Took out the main board again, slathered it with a thick line of flux around all 4 sides of the BGA, and reflowed even hotter and longer ... figured I had nothing to lose. Tried again and if anything it was worse, failed after about 7 power-cycles. Really I think it's just random whether it fails on the 7th or 10th try ... it's just intermittent. As a last ditch effort, I figured I would do even MORE reflow, this time reflowing several other larger chips plus more reflow of the main BGA. At times the temp got to 270+ at the sensor. Same results ... still fails to power up properly ever 7 attempts or so. Again, the failure mode is that the Red standby light stays (should turn off as soon as the power button is pressed), and I see the screen turn a little milky but power-up never completes and nothing on the screen.

So at this point I think I've invested about as much time and patience on this TV as I want to, so unless anyone has another idea of something quick I can try, I'll button it up and try to find a home for it, and/or send it to the recycler once I have a replacement.

I do feel like I have gained some experience in reflowing, that may come in handy later, even though it didn't do the trick in this case.