Panasonic TC-L32X1

[arunningpir8]

Hey guys I have one here that should be simple, just looking for a quick answer on what you guys think.

I got this TV the other day, and it would power on, but randomly turn itself off, and then click the relay a few times and turn itself back on, usually with a message "an error has been detected and recovered."

Now there were also a few times where the TV would just "freeze" with a screen of a lot of vertical bands of color before doing the power cycle as mentioned earlier.

Today I try to start measuring stuff and low and behold now it won't turn on at all. Now all I get is the relay clicking on and off repeatedly. The one thing I have noticed is that if I hold the power button in after about 5 seconds the relay will turn on without turning off again until I let go of the POWER button. When I do this, the main cap will go from 400v to about 170v. Also, when I don't touch anything the main cap is usually going from 400-350v synchronous to the relay clicking.

Now I'm pretty sure the problem lies within the power board, however the fact that the screen froze with the weird vertical lines of color when it was working still puts me a little on edge on if it could be an A board problem.

Pics of both below.

Any suggestions?

[tom66]

Re: Panasonic TC-L32X1

I would be looking more at an A board issue.

When the TV fails to power on, does the light ever turn red and blink an error code?

[arunningpir8]

Re: Panasonic TC-L32X1

Unfortunately the red standby light never turns on. When the set was working, the light only came on when the TV was powered on. Just for my piece of mind, if I was to lean towards an A board issue, why would the main cap be dipping between 400 and 350v? And also any idea as to why holding the power button in will cause it to dip to 170v?

I'm trying to get better at understanding the power circuits on these TV's and I enjoy reading your posts tom as they are always insightful and explanatory.

[tom66]

Re: Panasonic TC-L32X1

170V is normal for standby, it should be around 400V in operation.

[arunningpir8]

Re: Panasonic TC-L32X1

Also, here is a pic that somewhat shows about what I would see the couple times it froze before shutting off:

http://www.avforums.com/forums/attac...2011161229.jpg

I'm thinking of ordering the A board, I just wish I had a little more confidence in what the problem might be.

[tom66]

Re: Panasonic TC-L32X1

Definitely thinking main board, though could be t-con (less likely though.)

[arunningpir8]

Re: Panasonic TC-L32X1

Alright, A board was my first guess as well way back when I first got the set. My last question is would the relay be kicking on and off because of a short or because of a power drop or because of the micro not responding accordingly? I just haven't worked on a TV with relays before so I'm curious as to their operation in this situation.

[tom66]

Re: Panasonic TC-L32X1

Would possibly be the MCU not working properly.

[arunningpir8]

Re: Panasonic TC-L32X1

Awesome thanks again for your help I'll try looking for an A board.

[arunningpir8]

Re: Panasonic TC-L32X1

Ok, so the TV just started working again and has been working for long periods of time now. I was able to pull SOS codes via the service menu, and the SOS codes point to an SOS 4, which according to this TV's service manual is a "DTV 12v" error and says it's an issue with the P Board. I was *just* about to order the A board and then I saw this and am now doubting it again.

Now, I never got the SOS code from a blinking power light, ONLY from the service menu did I get this information. See the pictures below.
Anybody have experience with a similar Panasonic TV or SOS code? Now I'm looking at the P Board and measuring component after component trying to find something wrong but alas nothing.

Thoughts?

[arunningpir8]

Re: Panasonic TC-L32X1

Also had a question, when looking at the service manuals, a good portion of the power lines are highlighted orange. Does this mean simply that they are power lines, or does it mean that they are hot? I saw some power lines that were not highlighted orange that is why I was wondering. Didn't find anything about the coloring in the manual.

[tom66]

Re: Panasonic TC-L32X1

SOS4 is usually over-voltage on one of the lines, so it can be P board. However, an A board fault can lead to mis-detection of fault codes.

[arunningpir8]

Re: Panasonic TC-L32X1

Alright so I already ordered the A board but just now while the TV was on it turned on and off a couple times and then started blinking 13 times. This shows up in the manual as an SOS which points to the A board being the problem. Now all it does when you plug it in is make the initial click and then the red led goes solid, just like if it were on, however nothing actually powers up.

I'm just wondering if it would be safe to plug the new A board in when it comes or if you think there might be a power supply issue that blew this A board?

Thanks again for all your help!

[tom66]

Re: Panasonic TC-L32X1

Panasonic usually have lots of protection mechanisms, they'll shut down before an over-voltage occurs -- but it would be a good idea to check the outputs from the PSU are good.

[arunningpir8]

Re: Panasonic TC-L32X1

Welp just got the board in yesterday. I have been running it for hours without issue so knock on wood but it seems that the A board WAS the issue. Thanks again Tom66 for your countless efforts on these forums