Panasonic TC-P42C2 SOS10 (10 Blinks)

[koerneka]

Hi all

It's been a while since I've last posted. Anyway, long story short, I've got my hands on 4 plasmas 2 LCDs (they were too cheap to pass up!). One of which is a Panasonic Viera, 42", TC-P42C2. Great shape, except it is reporting SOS10, or 10 blinks of the red power light.

I've gone through some research online and testing, although it was a couple of months ago. I've isolated the SN board as the faulty board. However, as I am good with a multimeter and proficient with a soldering iron, I'd like to try to diagnose the SN board at a component level before replacing the entire board. Upon visual inspection, nothing is out of the ordinary (solder joints, caps, etc).

I have located the Panasonic service manual for this unit. It is available on Elektrotanya here. If you are unable to download from that link, I have also located the manual on Google Drive, where no download is required here.

Page 6 shows the location of the SN board from the back of the TV, while pages 58-68 have a schematic diagram of the board, and pages 74 and 75 show a visual of the board.

As I said before, I am good with a soldering iron and multimeter, but I am a little over my head in terms of testing the components on the SN board.

Anyone have a little bit of wisdom to share?

Thanks!

[tw2005]

Re: Panasonic TC-P42C2 SOS10 (10 Blinks)

How did you conclude bad SN?
Did it change from 10 after isolation?
Was SN2 or SN3 shorted?
Any shorted IGBTs?

If no obvious shorts try measuring input resistance for the P5V line pin 30-gnd SC20(TP16,17-gnd, or across C561)

[koerneka]

Re: Panasonic TC-P42C2 SOS10 (10 Blinks)

I concluded the SN board last time I worked on the unit by following a previous thread on another site with the same symptoms as my TV. The SOS changed to I believe 6 or 7 blinks, as the thread stated it should. I've since lost the link to that post.

I haven't much component-level testing yet; that's the area where I need some help.

Maybe I should rephrase, as well. I know how to use a multimeter, but I'm not too familiar with which components to test, or how to properly test them. If I could get a little more guidance as to which components, I'd be very greatful.

[mardocdor]

Re: Panasonic TC-P42C2 SOS10 (10 Blinks)

That's what this forum are here for

[tw2005]

Re: Panasonic TC-P42C2 SOS10 (10 Blinks)

I concluded the SN board last time I worked on the unit by following a previous thread on another site with the same symptoms as my TV. The SOS changed to I believe 6 or 7 blinks, as the thread stated it should. I've since lost the link to that post.

I haven't much component-level testing yet; that's the area where I need some help.

Maybe I should rephrase, as well. I know how to use a multimeter, but I'm not too familiar with which components to test, or how to properly test them. If I could get a little more guidance as to which components, I'd be very greatful.

So you could start with the checkpoints I listed (SN2,SN3, P5V in at SC20 )and see if any short cct, test all transistors mounted on the heatsinks marked as "Q..."

nothing special needed for this, set the meter to diode mode and just bell out the leads on the transistors. list the results.

Since this is essentially a combined SC,SD,SU also check for any shorts between gnd(or any of these TP59-63) and the output pins at connectors SN11-18 . If there is then there's not much point going on as the SMD buffer ICs (QFP 128 pin) are blown.