Panasonic Viera TX-32LXD600a blue screen

[andy smethurst]

Re: Panasonic Viera TX-32LXD600a blue screen

The original DG board is the one with the parts not fitted, and it must have worked before?

The new one has the extra components fitted, and it seemed to pull the standby voltage down to the same level as the original DG board?

I tested the parts mentioned on the new board as well as that 100.Ohm resistor and they were good. This was done after I used it, and it did no harm to the board.

Yes, my error,I do not have a new Tcon board, I was associating the DG board to the Tcon board.

The Tcon board and the Inverter board don't seem to be mentioned in the service manual.
My bench power supply has Amp limiting as well, should I turn it down to zero or next to zero, and gradually turn up the voltage to replace the few missing volts,and see if the amp gauge starts to increase, and if it dose I will stop.

I dont want to fry (toast) the board, but theres not much left to do. I was thinking about doing this before,but wanted to avoid this sort of last resort action. Thanks again Toasty for your assistance.
Regards:Andy.

[Toasty]

Re: Panasonic Viera TX-32LXD600a blue screen

The T-con and inverter boards are most likely included as part of the panel assembly. Therefore they are not broken down in schematics. Replace panels as an assembly I guess. Weird.

Can you pull the connector -AT- the DG from the AP and measure the STB7V?
Could this be a pinched interconnect cable?

If this is a 2nd DG, then perhaps the T-con or the panel is/are bad. Why the STB7V is going low is a mystery.

[Toasty]

Re: Panasonic Viera TX-32LXD600a blue screen

What is the part number on the original DG?

[rmoody]

Re: Panasonic Viera TX-32LXD600a blue screen

Could you please give us a pic of the Tcon board? It could help

[andy smethurst]

Re: Panasonic Viera TX-32LXD600a blue screen

The original DG board is the one with the missing components,but must have worked before?
And I am sorry,I thought the DG board was the Tcon board, as there is no listing of a Tcon, or the Inverter board in this service manual.

My bench power supply dose have current limiting,and I thought about this before, but kept putting it off, hoping to find a more friendly solution, without frying something, but I suppose there isn't much else left to do. Thanks again Toasty for your help.

Regards:Andy.

[Toasty]

Re: Panasonic Viera TX-32LXD600a blue screen

Repeating yourself? Set has driven you around the bend, eh?

[andy smethurst]

Re: Panasonic Viera TX-32LXD600a blue screen

Yes, it is. I removed the T-con board and checked the fuse,diodes and all smd transistors, inductors, resistors, and looked for shorted caps. nothing unusual there

I am going to search for the data sheets for the IC's on the board so that I can do a cold test at least on them. That just leaves the T-con processor, and I can't do anything with that.

I have found a T-con board on Ebay for $29. Im worried this wont work too. I will see how things go, and keep intouch.
Thanks again for all your help Toasty, you've been great.

Regards:Andy.

[Toasty]

Re: Panasonic Viera TX-32LXD600a blue screen

What is the part number on the original DG?

Could you please give us a pic of the Tcon board? It could help

Did you try the bench supply bit? I'd set the current for <250mA and try it and see. It still makes no sense what is dragging it down, unless it's something on the other side of that transformer. It does supply 2 voltages, I believe. Back to the schematic.....

[Toasty]

Re: Panasonic Viera TX-32LXD600a blue screen

Andy - what is your mains voltage?

Can you pull the connection of either DG3 or H3?

If the set will still turn on, check the STB7V then.

Do the front LEDs work?

God, my brain hurts!

.

[andy smethurst]

Re: Panasonic Viera TX-32LXD600a blue screen

The mains AC voltage is 240v
I pulled the DG3 before, but did it again. The set turns on but the STB.Volt remains the same.
The front Leds work properly, with no blinking.

I did the bench power procedure.With the set in STB and Amp limmit at 250mA I connected to pin7 on the AP5 - DG5 connector, and started at 2v up to 10v.
I noticed that there was no large increase in Amps within this range.
It only draws about 150 mA-200 mA at most. (looks good)?

At increasing intervals I turned the set: Off to STB to On.
When at 10v in STB, I turned On, and the volts dropped to 9v but no increase in Amps.

This procedure caused no harm to anything: no Pops, no Sparks, no Burning smells.
I would have expected some stress to components if there was a short somewhere.?

Is this normal? and it's the service manual that has the error? and Im looking in the wrong places? I don't know!

What puzzels me, is that I get a good picture on the output to an external screen, but when I addjust the volume there is no indicator Bar on the screen, or when I change channels, there is no indication of the change of channel.
All this and the missing OSD, sort of turns me more to the T-con board? I don't know.

Thanks Again for all your help. I'll keep intouch. (If not certified first)

Regards: Andy.

[Toasty]

Re: Panasonic Viera TX-32LXD600a blue screen

DG --> T-con --> Panel

Disconnect the DG from the T-con. (DG6, DG7, DG11)

STB7V ?

[andy smethurst]

Re: Panasonic Viera TX-32LXD600a blue screen

Now I notice that when I press the ON button, the volts race up to 10.5v until the relay klicks on, then it declines to 4.6v.

With all three connectors removed I still get 5v, so I re-connected DG7 (LVDS)
With just DG6 or DG7 removed (either one or both) I get 5v STB, but then when I turn on with the remote the relay klicks again, and the voltage goes up to 7.6v

While this is happening the STB led is blinking once every 4 seconds, because of the dissconection I suppose?
What do you make of this Toasty? I didnt expect this, as the invertor board seems to be working and the screen has a nice even blue look to it, as if there is no input selected.

Thanks again for your great ideas.
Regards:Andy.

[Toasty]

Re: Panasonic Viera TX-32LXD600a blue screen

Okay. All 3 connectors go to T-con?

I'm repeating myself (3x) and one for rmoody (2x):

- What is the part number on the original DG vs the one you acquired?
(Sometimes a revision number is present)
One could be from a 26" model. Was the set worked on before?


- Could you please give us a pic of the Tcon board? (top & bottom)

Yes, the every 4 second blink is the Inverter error signal. Page 11

EDIT: YAY!! Finally found the Service Guide for this set.

Flowchart

No Picture

ALL Input Source Picture NG ? > YES > No picture but OSD is displayed ? > NO > LCD Panel or DG board




.

[andy smethurst]

Re: Panasonic Viera TX-32LXD600a blue screen

I stuffed up, I mean DG6 or DG11 removed (either one or both) produce 7.6v .

The wiring of DG6 and DG11 goes to 2 connectors on the Inverter board.

The new DG board is from the same size and model as the original and has the same number: (TNPA3863 1 DG)

I will have to buy some batteries for my camera to take shots of the board.

You found the flow chart? DG board or Panel? Oh well Thanks again for your help Toasty

I will keep intouch

Regards:Andy

[Toasty]

Re: Panasonic Viera TX-32LXD600a blue screen

So DG7 goes to the T-con?

When it says Panel, that includes the T-con. Not called out in parts as you noticed before.

Sometimes they can be fixed, so good pics may help.

Flow chart / service manual makes no mention of the STB7V. They -DO- talk about STB5V !! So, we may have been chasing the wrong item and the schematic may be wrong (on multiple counts!!!)

[andy smethurst]

Re: Panasonic Viera TX-32LXD600a blue screen

Yes the DG7 is the (LVDS) cable strait to the T-con board. All the 12v supplies to this connector are good and I checked the fuse on the T-con board and this is OK.

The difference between the two DG boards that I've noticed.

In Australia, we have both analogue and digital transmission, as this dosen't expire for a while yet, even though all stations have gone digital now.(we are slow down here)

When using the original board, without the XV board (IDTV tuner) pluged on top of it,
I receive the Analogue stations only. This is good for testing as you can hear the broadcast and you know what mode you are in.

With the XV board pluged on top of the DG board you get the digital reception.
This means you have two AV (button presses) selections to chose from(one for analogue,and one for digital).

With the new DG board (from UK) you get no reception without the XV board.
You can still test but get a sound rasster.
The XV board has to be attached to get reception and this is pure digital.
This means you have only one AV selection (no choices)

If this makes sence to the additional components on the new board, Maybe Both boards
are good, and the T-con board is stuffed? What do you think?
Thanks again for your knowledge Toasty.

Regards:Andy.

[Toasty]

Re: Panasonic Viera TX-32LXD600a blue screen

I think I would check the T-con as best I could and perhaps order the replacement. If it does not fix the problem, at the least you could get your money back for the board by reselling it. Plus you have the other boards to resell "as is".

It would be great if you could find another of these sets for cheap with a working panel. Build a working one and sell off all the boards from the other. Or, keep them for your own spares.

[andy smethurst]

Re: Panasonic Viera TX-32LXD600a blue screen

Yes, I think I,ll try to get a T-con board, and I have been looking for another faulty set at the salvage auctions, but I don't like my chances of getting the same model.

When I get another T-con board, I will let you know the results.
Thanks for your wonderful and time consuming help Toasty.

Regards:Andy.