Panasonic TH-42PY85PA 10 blinks

[Hombre]

Hi guys

I have problem with this set. It is almost the same tv as US version TH-42PZ85.
It has 10 blinks code. This are the things that i tried so far:
-recaped (1uF) MC301 and M201 on P board - ETX2MM702 - still 10 blinks
-checked all voltages as suggested in TM for 42pz85, everything is ok - 15V, Vd, Vsus, 5Vstb...
-IC's 5400 and 5401 are producing 5V and 9V as they should
-tested 30V for tuner - ok
-tried to disconect everything except A6 and A7 connectors - i got white screen, panel is ok
-disconnected A6 and A7 - green leds on SC and SS boards are on
-tried disconnecting K, GS and GH board - still 10 blinks

So voltages seem fine, there is 5, 9 and 30V but Q5522 is still sending SOS signal to shutdown the power

I really don't know what next to check, please help


And one more question. On P board there is a diode D504 as seen on picture. The thing is that i can't measure it with DMM as regular diode - it is open (doesn't conduct in either way - i have unsoldered one side from pcb to test it). Is that because it consists of 2 diodes (one regular and one zener) or is it faulty? I am asking because i don't know, please don't be harsh (in SM description for D504 is "power clamper")

[tom66]

Re: Panasonic TH-42PY85PA 10 blinks

Carefully inspect the SD card slot for debris, coins, other kids' stuff -- several users have had this issue.

[Hombre]

Re: Panasonic TH-42PY85PA 10 blinks

Unfortunately nothing is stuck in SD card slot
Also eliminated it by disconnecting A52 from A board - 10 blinks present

I will try to inspect 3.3V a bit more

[R_J]

Re: Panasonic TH-42PY85PA 10 blinks

I just did a th-42px75u that had pennys in the sd slot, It gave 13 blinks
If I remember I did have a Panasonic once that gave 10 blinks and I thought it was the power supply, turned out to be bad (shorted) chip on ribbon from c board to panel.

[Hombre]

Re: Panasonic TH-42PY85PA 10 blinks

Ok, made some progress

The fuse PA5600 on A board ( TNHPH0712 ) that is on 15V supply line for IC5600 and IC5601 is blown.
IC5600 is for 3.3V and IC5601 for 1.2V and 1.8V lines.
15V supply line (after the fuse) is shorted.
3.3V - gnd measures around 510 ohms just like 1.2V-gnd; 1.8V-gnd is around 330 ohms - i believe that is ok- they aren't shorted?
Q5607 measures open (0ne side only) but i really can't see how would that affect 15v line to get shorted to gnd, am i right?
Any suggestion what to check, measured all diodes in that circuit but they seam ok


thx

[Hombre]

Re: Panasonic TH-42PY85PA 10 blinks

Ok guys, TV is on and running

Small ceramic capacitor C5612 was shorted and that burned fuse PA5600 on 15V line.

Repair cost under $2

I have another patient (Sony KDL-37p3000), but he deserve another topic

Thank you!

[tom66]

Re: Panasonic TH-42PY85PA 10 blinks

Glad to hear it's fixed! One good way to trace a short out is to apply 15V using a lab supply, current limited to around 1 amp. Then freeze spray parts of the board. The shorted component will get hot, melting the freeze spray, allowing you to easily locate it.