Sunday, February 10, 2013

Repairing Plasma TV Panasonic TH42PV500M

Plasma TVs are very expensive especially the one that is made from Japan. You need to pay more attention if  the screen size is very big . I received this Plasma Tv with LED blinking, no picture and no sound. Self-Check is used to automatically check the bus lines and hexadecimal code of the Television set , but there’s no access, the screen is always black.

According to the manufacturer information, no picture and no OSD  with SC board LED ok and SS board LED ok means that the D board is faulty. In my case the SC & SS boards LEDs are ok, but the D board is not faulty because when checking the output voltage, I noticed that the 14v was absent. In normal condition when A board receives +5v , the output +15v and the A board  will energize the signal SW to process circuit.

My intuition tells me to isolate H, TA and TB board block. When it’s done I powered on the set and the screen works, but the set does not recognize the aerial, Av1 and etc and only input vga works as monitor for pc.
Now I can access the self check as follows :

Panasonic M2PD05A1
V2.000A 24/06/2005
Self check failed
MEM :0.k
GC4P :0.k
GC3FS :– –
AVsw1 :– –
AVsw2 : – -
Tun1
Tun2 :- —
.
.
.
.
.
SDM :–
HDMI :–
ADV :O.K
In normal conditions the self check is:
Panasonic M2PD05A1
V2.000A 24/06/2005
Self check
MEM :0.k
GC4P :0.k
GC3FS ok
AVsw1 ok
AVsw2 : ok
Tun1
Tun2 ok

. ok
. ok
.
.
.
SDM :0k
HDMI :0k
ADV :O.K

Certainly components or ICs or both on H,TA and TB board are defective.
After checking all the related components, finally I concluded that the IC 3005 (video sw) was faulty. No spares parts, what to do? I had spent time to find the problem! I must  give second life to that set! How?

I tried isolate contact by contact between PA board and H board and check the result of self check. Finally I  have isolated the +14v and the set recognized the HDMI. The set works fine now with external HDMI DTTV/home cinema and satellite.

Read more here.

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