Panasonic Viera TX-32LXD600a blue screen

[andy smethurst]

Hello: This 32" LCD TV powers up fine, and has sound, but it has no video, but the screen dose come on with a dark blue screen. I cant seem to locate a service manual either. could this be a mainboard problem? or what. Has anyone had experience with this model? Any information or help would be greatly appreciated.

Regards:Andy.

[PlainBill]

Re: Panasonic Viera TX-32LXD600a blue screen

Hello: This 32" LCD TV powers up fine, and has sound, but it has no video, but the screen dose come on with a dark blue screen. I cant seem to locate a service manual either. could this be a mainboard problem? or what. Has anyone had experience with this model? Any information or help would be greatly appreciated.

Regards:Andy.

Service manual is available at Elektrotanya.

This could be a main board problem, or possibly the tcon.

PlainBill

[alexanna]

Re: Panasonic Viera TX-32LXD600a blue screen

Hello: This 32" LCD TV powers up fine, and has sound, but it has no video, but the screen dose come on with a dark blue screen. I cant seem to locate a service manual either. could this be a mainboard problem? or what. Has anyone had experience with this model? Any information or help would be greatly appreciated.

Regards:Andy.

If you can get to the T-Con board, there may be a couple of fuses that should be checked.

[andy smethurst]

Re: Panasonic Viera TX-32LXD600a blue screen

Thanks again Plain Bill for the service manual site, I removed the T-con board to look for smd fuses, but these (and other) small components are not detailed on the board.I have seen lots of these before,and can usually recognize them. I have found some components that resemble smd capacitors, rectangle and tan colour but have a band around the center and this is also soldered to a track at the base, as well as the usual ends. When I tested these for resistance they seemed like a typical fuse resistance (0.4ohm),except for 1 that measured (3.4ohm) are these fuses, or inductors?. Thanks agai for any help.
Regards:Andy.

[PlainBill]

Re: Panasonic Viera TX-32LXD600a blue screen

Thanks again Plain Bill for the service manual site, I removed the T-con board to look for smd fuses, but these (and other) small components are not detailed on the board.I have seen lots of these before,and can usually recognize them. I have found some components that resemble smd capacitors, rectangle and tan colour but have a band around the center and this is also soldered to a track at the base, as well as the usual ends. When I tested these for resistance they seemed like a typical fuse resistance (0.4ohm),except for 1 that measured (3.4ohm) are these fuses, or inductors?. Thanks agai for any help.
Regards:Andy.

I've been saying this a lot lately. DAMNIFIKNOW.

Now, if someone took a picture and attached it using 'Manage attachments' - below the text entry area - I MIGHT have a clue.

PlainBill

[andy smethurst]

Re: Panasonic Viera TX-32LXD600a blue screen

Hello,again. The component was a line filter. Anyway all voltages and test point voltages were fine,except for a pin from the power supply to the Tcon board. this is a stand-by line and should carry 10v stb, and 7v On,I get 5v stb and 4.6v On. When disconected from Tcon board,I get 11v in stb mode from the power board,so looks like a short on the Tcon board.I chased the line using the schematic to no avail.I purchased a Tcon board on Ebay(used), and this didnt fix the problem. I hooked up the Tv to another Tv and the picture shows fine on an external screen.All voltages to display panel are correct,and I checked the panel fuse(ok)also.The inverter board has all correct volts and is working. Where else can I look, or what should I look for? Thanks.
Andy.

[PlainBill]

Re: Panasonic Viera TX-32LXD600a blue screen

Hello,again. The component was a line filter. Anyway all voltages and test point voltages were fine,except for a pin from the power supply to the Tcon board. this is a stand-by line and should carry 10v stb, and 7v On,I get 5v stb and 4.6v On. When disconected from Tcon board,I get 11v in stb mode from the power board,so looks like a short on the Tcon board.I chased the line using the schematic to no avail.I purchased a Tcon board on Ebay(used), and this didnt fix the problem. I hooked up the Tv to another Tv and the picture shows fine on an external screen.All voltages to display panel are correct,and I checked the panel fuse(ok)also.The inverter board has all correct volts and is working. Where else can I look, or what should I look for? Thanks.
Andy.

If I understand you, you connected the LVDS cable from this TV to the TCON on another TV, and the picture displayed perfectly. That eliminates the main board and probably the power supply. The remaining suspects are the TCON and the LCD panel.

You have tried a different tcon, which did not work. Do you get the same incorrect voltages with the replacement tcon? I see two possible causes - a power supply with insufficient current capacity, or a bad panel.

Ultimately I come back to the same problem - without pictures I can't help you.

PlainBill

[Toasty]

Re: Panasonic Viera TX-32LXD600a blue screen

>>I hooked up the Tv to another Tv and the picture shows fine on an external screen.<<

How?

Any OSD?

Pictures PLEASE.

[Toasty]

Re: Panasonic Viera TX-32LXD600a blue screen

Try entering Self Check mode. See if you get any display.

"Self-check is used to automatically check the bus lines and hexadecimal code of the TV set. To enter Self-Check mode, keep pressing the STATUS button on the remote control and press the down (-/v) button on the TV set. To exit Self Check, switch off the TV set at the power button."

MEM  O.K.
GC5  O.K.
GC3FS O.K.
AVSW1 O.K.
AVSW2 O.K.
TUN1  O.K.
VIF  O.K.
MSP  O.K.
SDM  O.K.
IPC  O.K.
HDMI  O.K.
ADV  O.K.

TX-32LXD600 

OPTION 1  01 
OPTION 2  10 
OPTION 3  28 
OPTION 4  75 
OPTION 5  EA 
OPTION 6  B3 
OPTION 7  08 
OPTION 8  80 
OPTION 9  00 
OPTION 10 80 
OPTION 11 C1 
OPTION 12 A0 
OPTION 13 30 

CHECK E4

[U]Display[/U] [U]Ref. No.[/U] [U]Description         [/U] [U]P.C.B.[/U] 
MEM   IC1102  EAROM             DG-Board 
GC5   IC4037  GLOBAL CORE          DG-Board 
GC3FS  IC4020  GLOBAL CORE FOR SUB      DG-Board 
AVSW1  IC3005  AV SWITCH           H-Board 
AVSW2  IC2105  AV SWITCH           H-Board 
TUN1   TU3201  MULTISTANDART SOUND PROCESSOR H-Board 
VIF   TU3201  VIDEO INTERMEDIATE FREQUENCY  H-Board 
MSP   IC2106  MAIN SOUND PROCESSOR      H-Board 
SDM   SD-MODULE MPEG/PHOTO VIEW, SD RECORDING SD-MODULE 
IPC   IC8013  HDSL PEAKS Lite        XV-Board 
HDMI   IC4026  HDMI I/F RECEIVER       DG-Board 
ADV   IC4019  A/D CONVERTER         DG-Board 

If the CCU ports have been checked and found to be incorrect or 
not located then " - - " will appear in place of "O.K.".

.

[andy smethurst]

Re: Panasonic Viera TX-32LXD600a blue screen

The TV has AV input and AV output connectors(we use AV not SCART in Australia) on the main board,and I connected the leads from the output of the faulty tv to the input of an older but working TV, and when I set ths TV to AV.1 input, it displays the channel the faulty TV is tuned in to. This at least proves that the tuner is working. I still had the incorrect STB voltages with the new TCON board, but I think the power board is Ok,because when the connector is removed from the Tcon side and measured on the power side it is correct.This is the reason I got another Tcon board as I thought there was a short somewhere pulling the voltage down to this level. Thanks Toasty,I haven't got around to trying the OSD yet,I cant see why this wouldn't be displayed as well. I will try the self check.Oh I dont have the original remote for this set,just a cheap universal one,Ill do some reading of the manual,there may be a way arround this. Thanks for all replies.
Regards:Andy.

[Toasty]

Re: Panasonic Viera TX-32LXD600a blue screen

The lack of blink codes seems to me to mean the power supplies are okay.
Verify the voltages on Page 9 of the Service Manual.

You do need an original remote to get these to work properly. Especially for the service menus.

Part Number: N2QAYB000047
They're on eBay for reasonable (<$20) to ridiculous (>$50)

Try the SD card input and the VGA (computer) inputs also.

There is usually a "Factory Reset" function.
See if the Owner's Manual has that noted.

The lack of -any- OSD has me thinking the DG board may be bad.
Did you have OSD when you tested on the other TV?
Was this subjected to a power surge or nearby lightning strike?

PS: Please break up your messages into a few paragraphs. All one long one is very hard to read/follow especially when the subject changes.

.

[andy smethurst]

Re: Panasonic Viera TX-32LXD600a blue screen

Thanks Toasty, I did plan to get a proper remote If I managed to get the set working, anyway I tried the set up as above again,and the picture is quite good.

I can change channels and volume,but there is no volume bar displayed when turning the volume up or down.

The functions button dosen't display anything, no EPG, no OSD
I did the page 9 Tp tests a while back,all tested fine except Tp7201, which is a STB supply and should be 7v+-1v normal mode, and 10v+-2v in STB. I am getting 4.6v and 5.2v respectivly. I had the same results even when I changed the Tcon board.

When I remove the connector from the Tcon board I measure 11v in STB on the power supply side. The set wont get out of standby with this connector removed, so cant measure normal mode volts.

This supply feeds several Ic's on the Tcon board,and even though the supply is low the output volts are correct, except one,(ic.1109) which is a reset Ic and is only 4v(in)instead of 7v(in) there are no out measurements mentioned.

I know this looks like a Tcon fault,thats why I got another one, Can they both have the same fault? I wasn,t expecting the missing OSD as well.

I have tried other inputs with DVD, and Set Top Box. I get sound only. I havent tried the SD card or Pc input yet but I will next. Thanks again Toasty

Regards:Andy.

[Toasty]

Re: Panasonic Viera TX-32LXD600a blue screen

PlainBill said a while back this could be an indication of a weak supply line. Track the 7v line back to the source and see if there is a fault.

Check FL4047 on the DG board. Page 59 of the schematic, far lower right off of connector DG5. It is -very- tiny maybe 1mm x 1.5mm. It is a filter for incoming 7v STB power and I've had these short before on plasmas. Essentially a pass through filter cap, you should read zero resistance left to right and zero resistance top to bottom. It should show open from left or right -to- top or bottom.

Look at this as a pinout of one of them.

┌─3─┐
1░░░2
└─4─┘

1 & 2 are power through.
3 & 4 are ground.

See attached image from another thread for size relationship.

.

[Toasty]

Re: Panasonic Viera TX-32LXD600a blue screen

The STB7V affects or is associated with IC1107, 1108, 1109. All on the DG board.

Check the resistor R1251 (100Ω) near Q1148 (DG Board).

Check C7101 on the AP board. 4700uF @ 16v.

The STB7V is a linear supply, not SMPS. It is mains transformer fed (T7101), so if it's low, something is dragging it down. Read voltage from D7103/D7105 anode to D7102/D7104 cathode. What voltage?

.

[rmoody]

Re: Panasonic Viera TX-32LXD600a blue screen

Sounds like a bad tcon really. Remember it's always possible that the one you bought from fleabay could have been bad. It's happened to me.

[andy smethurst]

Re: Panasonic Viera TX-32LXD600a blue screen

I tested FL4047 line filter = 0.ohm. and C7101 checked Ok. R1251(100.Ohm) and Q1148,and IC1107, are not fitted on original board, but are on the one I got from the UK.

This could be because we(Australia) use RCA connectors on the main board, and UK use Scart? I don't know.

The voltages for the diodes read, STB=5v and ON=4.6v. If I remove the AP5 connector from the DG board,the STB=12v on the diodes.

I did all AP board TP. tests, and all Normal tests were great except for the low STB point,
but tests in the STB mode, some of them (tp7301, tp7303, tp7601) read the same as the Normal (on) test. Full volts instead of a trickle voltage.?

Is this a problem or an error in the service manual?
Thanks again for any more clues.

Regards:Andy.

[Toasty]

Re: Panasonic Viera TX-32LXD600a blue screen

That's not the answer I wanted for the FL4047. I want to know if you are getting a resistance reading between the ground (3 & 4) and the through line (1 & 2) indicating a short.

I'm fairly convinced the DG board has a problem because the STB7V only feeds to that board and not out to the panel. All the other resistors feeding the components attached to the 7V line are in the 10k and up range, not enough to pull it down to 5 volts from 12v that you measured unloaded. The 100Ω resistor (if it was the feed to the overload) would be smoking.

The other thing that may be worth checking are the 4 diodes that make up the bridge rectifier for the 7V.

[Toasty]

Re: Panasonic Viera TX-32LXD600a blue screen

>>This could be because we(Australia) use RCA connectors on the main board, and UK use Scart? I don't know.<<

Main board? You mean H board. DG is the main board.

Have a number or pic of the original T-con?

Have an adjustable bench power supply?


>>R1251(100.Ohm) and Q1148,and IC1107, are not fitted on original board, but are on the one I got from the UK.<<

That's very odd. You've a replacement DG? I thought you only had a T-con replacement.

These are on the DG board. Q1148 acts as a 5v regulator feeding the IC's and draws its' power from the STB7V.

.

[andy smethurst]

Re: Panasonic Viera TX-32LXD600a blue screen

sorry. I meant the H board for the RCA connectors. The DG board is what I have a replacement for, and the numbers (TNPA3863 1 DG) are identical,and so was the model TV. It has the vacant pads and labelng for the omited parts.

The resistance for FL4047, from through to ground,(1 to Gnd,and 2 to Gnd)= 202k Ohm.

I removed all of the rectifier diodes to test properly, and they were good. I did the same with the surounding diodes just to make sure.

I do have a variable bench power supply? Thanks again for the help.

Regards:Andy.

[Toasty]

Re: Panasonic Viera TX-32LXD600a blue screen

Put the original DG back in. I see no point in testing with missing components. There is no call out in the schematic or parts list that those parts were in one version of the board and not another. Something's weird...?

So you did -not- replace the T-con then, correct?

I would try "helping" the 7V line with the bench power supply. I hope it has current limiting of some type. If not, try using an auto light bulb (parking) to help keep the current down and put an ammeter (DMM) in series. If the bulb starts glowing, something's wrong...