Panasonic TH-L55ET60A

[JohnML1975]

Hello and thought i would make a thread while i work on diagnosis of this TV
TV has green standby light
when i press on button, there is picture and no backlights come on
the red light, starts to flash slowly
there does not seem to a fault code that i can

i removed the backpanel and many screws had to be drilled out as they seemed to be seized
visual check of power, main, led, and t con boards reveals no damage or visible failure

i disconnected the main board and bak lights did not come on
i used thermal camera to look for any heat sources and found nothing interesting

need to start working through voltages

will share pictures later

[JohnML1975]

Update
there are no voltage check names from the power supply to the mainboard
so i checked all fourteen pins
i found voltages such as 1.9 and 3.3 and 5.5 so i think the power to main board is okay
i found no 24 v going from main board to the led driver board should be four pins with 24v and these dont have the 24 v
so i traced the 24v pins and these go straigjht to the cpu on the mainbaord
i am going to heat the cpu at 300 degrees for 20 minutes on low fan speed
shall try to reball the cpu this way and see what happens

will update later

[JohnML1975]

This was a fail for me
after heating per above i allowed the board to cool
placed back in the TV
completely dead

going to scrap and sorry this thread kind of went nowhere

[nomoresonys]

Yes that will kill it for sure, a typical reflow will gradually bring the solder to melting, the (time above liguidus) which is slightly above melting only requires about 60 seconds, so no wonder the chip is dead, 20 minutes is way too long.

[JohnML1975]

Thank you so much for this advice. I have tried this around five times and everytime it failed.
I did some research and found this video on reflowing
will try on next chip
How To Fix Your Dead Graphics Card Or Your Laptop GPU - DIY Reflow - Black Screen Artifacts Repair