Panasonic th-p42x20z plasma tv No signs of life

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philk

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#121079 24-Jun-2013 10:24

Hi
I have moved my lounge around yesterday, TV was working fine never had any issues with it.
I have the TV on standby but not off at the wall, flicked the switch off at the wall, moved the TV to a new location pluged it into a power board with 4 other items then turned the switch on at the wall.
Everything was able to turn on after that except the TV. It has not lights or signs off life, does not make a click sound.

I am from New Zealand so we use 240v power same as Australia

I have taken the back off and tested power, but not 100% sure where to go next, what I have found is what looks like a bulb - it has 65v8 on it... in the Panasonic service manual it says it is a seuge absorber (spelt like that) would this the technically a fuse/circut breaker?

when I have the power on I get 61.8V on one side nothing on the other.

How can I test this? could I bridge it out to see if the tv will come back to like and if so replace it?

Attached are some photos

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#842234 24-Jun-2013 11:08

Can you re post those images without adjusting the dimensions? Also double check the markings on the arrester. It's called a znr if you want to google it.

edit: it seems the forum is adjusting their size to fit (right click view image & it's ok) but would appreciate one that's not blurry :)

You're not on Atlantis anymore, Duncan Idaho.

grant_k

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#842244 24-Jun-2013 11:14

...
what I have found is what looks like a bulb - it has 65v8 on it... in the Panasonic service manual it says it is a seuge absorber (spelt like that) would this the technically a fuse/circut breaker?

when I have the power on I get 61.8V on one side nothing on the other.

How can I test this? could I bridge it out to see if the tv will come back to like and if so replace it?

Whatever you do, DON'T bridge it out!!!

Surge Arrestors are akin to a Spark Gap or Zener Diode. They are wired in parallel with the incoming voltage to clip the top off any spikes that come down the power line. If you bridge it out, you will likely create a direct short circuit across the power input.

MadEngineer

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#842246 24-Jun-2013 11:17

check the voltage after the black znr. as above, the painted gap that the lamp is across should indicate to you that you shouldn't short it.

You're not on Atlantis anymore, Duncan Idaho.

philk

17 posts

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#842258 24-Jun-2013 11:31

Those are the markings
I'll have to lift the board to test the voltage as I cannot access it from this side.

Thanks for the head up on not bridging across the other part

B1GGLZ

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#842260 24-Jun-2013 11:34

Have you tried plugging it into a different socket?
I've had several power boards over the years where one or more of the sockets became unreliable or actually died.
A lot of them don't always grip the pins on the plugs very well.

philk

17 posts

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#842261 24-Jun-2013 11:35

Funny you say that, yes I have tried a different socket only after I took it apart and my wife suggested that haha

Edit: I Managed to test the znr one side it is 234V and on the other side it is 60V
is that correct?

michaelmurfy

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#842267 24-Jun-2013 11:47

It's supposed to be like that - don't bridge it or if you do we accept no responsibility for electrocution. How are the Capacitors? Any of them looking a bit bulged or strange?

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grant_k

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#842271 24-Jun-2013 11:48

philk: Edit: I Managed to test the znr one side it is 234V and on the other side it is 60V
is that correct?

That particular ZNR has a breakdown voltage of 680V according to the data sheet here:

http://www.google.co.nz/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&ved=0CDMQFjAB&url=http%3A%2F%2Fwww.farnell.com%2Fdatasheets%2F652464.pdf&ei=i4fHUbeGGs7TkgXhmIHoDQ&usg=AFQjCNG8Hvf7-rZ0Sp6WFYRS8jKWJO7q_Q&sig2=IL5jUNSla7f49U32humlbQ&bvm=bv.48293060,d.dGI&cad=rja

It means that no significant current will flow through it at anything less than 680V. This is intended to stop voltage spikes getting further into the circuitry as mentioned earlier.

The voltages you are measuring sound normal, but without a circuit diagram, or spending a lot more time tracing out the circuitry, it isn't easy to say. If you are lucky, you might find someone with experience in servicing these TVs who could point you in the right direction. MadEngineer maybe?

philk

17 posts

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#842275 24-Jun-2013 11:52

I have inspected the whole board and looks fine, can't see anything out of shape or smell and thing burnt
Seems strange to me, I thought it would be a fuse but they are all fine too.

robjg63

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#842290 24-Jun-2013 12:11

Are there any flashing LEDs on the front.
This thread has a lot of stuff about Panny tvs and power issues - maybe have a look through there...:
http://www.avsforum.com/t/1001318/master-thread-for-panasonic-plasma-not-turning-on

Nothing is impossible for the man who doesn't have to do it himself - A. H. Weiler

philk

17 posts

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#842296 24-Jun-2013 12:17

Hi
I have had a look at the options about the flashing led, mine had none of that, was working fine like I said turned off unplugged moved to new spot turned back on and nothing no red light no flash no click

....

This is what I have just dicovedered not sure what they are called but would suspect that may be the problem,? unless it does something like drops power thinking it's in standby mode or something?

grant_k

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#842300 24-Jun-2013 12:21

philk: This is what I have just dicovedered not sure what they are called but would suspect that may be the problem,? unless it does something like drops power thinking it's in standby mode or something?

Those are interference-suppressor chokes wired in a Pi configuration. One is in the Phase leg and one in the Neutral. Voltages you have measured look about right. The wire slightly out of position doesn't matter at all.

The problem will be much further into the works than this. My guess would be that something in the SMPS has died.

robjg63

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#842302 24-Jun-2013 12:23

Have you tried leaving the power switched right off (at the wall) for say 10-30 minutes then switching it back on - just in case its got itself mucked up?
Saw a few posts in various parts of the web that suggested doing that...

In fact this thread may be worth a look:
http://www.justanswer.com/tv-repair/6ztxy-force-reset-panasonic-viera-factory-settings.html

Nothing is impossible for the man who doesn't have to do it himself - A. H. Weiler

philk

17 posts

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#842304 24-Jun-2013 12:24

I thought that one side would be constant voltage - positive side? should they not all be 234V or 234V and then another volt of some sort? maybe DC

philk

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#842305 24-Jun-2013 12:25

Yes, I had it off at the wall but plugged in - All night
Will unplug it now and leave it for a while

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