December 29, 2013

Panasonic Plasma repair TH-42PV80PA 106cm (LSJB1261-1 board)

The problem: TV starts and after 5 seconds it shuts down. Red led is blinking 2, 4, or 10 times.
(Be careful, there are high voltages only do that if you are master.)

The P board

I downloaded the service manual from the net. The blinks mean that there is a problem with my power board (P board). I got the panel from the TV and inspected the panel looking for burns, checked the diodes, capacitors and some resistors with multimeter but I didn't find problem.

Power LED Blinking timing chart

-Firstly I replaced the capacitors, only ones that has more or equal than 1000uF. Old times it solved the problem but it is not solved the problem.
-Secondly I replaced the Q406 FET (RJK5010), it is not cheap but I thought it will be good. ->not

After that I searched the Internet and forums about the problems and I found that the Panasonic plasmas has a "common" problem and it is possible to get a repair kit for it. The kit contains: F401 F402 C443 C444 Q406 R493 R439 R448 R449 R411 IC406 D431 PR402 R436.

Check these parts

Checked and replaced parts
I checked that parts and I found that the two of resistors are bad (R439, R493), they are open lined. Yeah. I found the real problem. I replaced them and plugged on the TV. Ohh the power switched off  and F401 F402 (t8ah250v) got open line. I changed IC406, F401, F402 too but the power switched off too. Type of IC406 power factor corrector: L6561,L6561D(this is better because it is SMD). It cannot solved the problem. I have to take more time to inspect the board...

It continues here (solution): PART 2.

No comments:

Post a Comment