Grundig 40VLE4421 - no picture

[betmen]

I changed few leds on led background and tv works for about one year.
It is not much in use.Then stops working again, I checked leds on background, all are ok.
When I light up the screen with lamp there is a picture but background is not working and you can`t se the picture on the screen.
When I touch connector for led background with probes of backlight tester they light up and tester shows 108V. After that TV turn on normaly and picture is ok, backlight is working. After TV is turn of again backligt is not working, just on first turning on GRUNGDIG picture on boot is shown for part of the second and after that is dark screen.
If I again touch connector for led background with probes of backlight tester, TV turn on with picture again. After turn of and on again there is no picture.

Voltages on connector S2401 are:
Pins 1 and 2 - 5,2V,
pins 3-7 - 0V - GROUND,
pins 8-11 - 19,08V,
STBY - 2,75V,
BL+ - 46,3V,
BL- - 0,47V (last two when backlight is working)
When backlight is not working:
BL+ - 18,85V,
BL- - 0V.
other pins are the same.
I changed all electrolites, checked diodes D2402,24112413,2406,2405,2415,2404,2416 on board and they shown ok measurements.

What can be the problem?

[dskall]

Re: Grundig 40VLE4421 - no picture

I would say bad connection or bad led.

[betmen]

Re: Grundig 40VLE4421 - no picture

I checked and checked again leds, even replace two which are working but they start working last of all leds (I gradually increase voltage on each led strip) so I think leds are ok.
Checked connector again today - ok.

Anybody have some idea?

[dskall]

Re: Grundig 40VLE4421 - no picture

With leds unplugged what voltage do you get from led connector when you first turn it on?

[betmen]

Re: Grundig 40VLE4421 - no picture

Connector unplugged - about 3,5 - 3,8 V for split of the second, then drop to 0v.
Then if I again touch connector (connector pluged in) with probes of backlight tester, after try to turn tv on it turns on normaly.
On connector first it get 112V then screen turnf off briefly and then the voltage gets to 132V. (this is normal procedure I think) onf tv is working.
Then when I turn it off and try to turn it on ... nothing ...

[Diah]

Re: Grundig 40VLE4421 - no picture

cancle the sockets solder the wires of LED direct to the boards.

[betmen]

Re: Grundig 40VLE4421 - no picture

I soldered all wires directly to led stripes and from connector to the board...nothing changed, so bad connection on leds and led cennector is ruled out... any other ideas?

[dskall]

Re: Grundig 40VLE4421 - no picture

Have you checked for bad solder joints on underside of led connector?

[Diah]

Re: Grundig 40VLE4421 - no picture

can you tell yours Tv chassis code? you have it on the lable at back cover

[betmen]

Re: Grundig 40VLE4421 - no picture

Tv chassis sticker is in attachment.
I think it is not bad solder joints because I soldered wires from connector directly to the elements on board which are connected to connector.

[nomoresonys]

Re: Grundig 40VLE4421 - no picture

show us a picture of your work.

[Diah]

Re: Grundig 40VLE4421 - no picture

Tv chassis sticker is in attachment.
I think it is not bad solder joints because I soldered wires from connector directly to the elements on board which are connected to connector.

yours chassis share same firmware with TT/TY

try to downgrade to V5, to close out if firmware did clitch at panel section.
how to:

Step 1:
Copy Target folder into USB memory.
Step 2:
Insert USB memory to the USB socket on the side of TV.
Step 3:
Press the “Program +” key of the keypad on TV and plug in the TV.
Step 4:
Hold down the “P+” key of the keypad on TV until you see that code installation has
started.
Step 5:
If the software is installed without any problems, TV will be started itself with the new
software.
Step 6:
Switch off the TV to remove the USB.

[betmen]

Re: Grundig 40VLE4421 - no picture

Picture of soldered wires...

[betmen]

Re: Grundig 40VLE4421 - no picture

yours chassis share same firmware with TT/TY

try to downgrade to V5, to close out if firmware did clitch at panel section.
how to:

Step 1:
Copy Target folder into USB memory.
Step 2:
Insert USB memory to the USB socket on the side of TV.
Step 3:
Press the “Program +” key of the keypad on TV and plug in the TV.
Step 4:
Hold down the “P+” key of the keypad on TV until you see that code installation has
started.
Step 5:
If the software is installed without any problems, TV will be started itself with the new
software.
Step 6:
Switch off the TV to remove the USB.

Chrome is block this files for download.
Whad do you mean by "yours chassis share same firmware with TT/TY"?

[Diah]

Re: Grundig 40VLE4421 - no picture

Chrome is block this files for download.
Whad do you mean by "yours chassis share same firmware with TT/TY"?

grundig TV with chassis TT use same firmware as your TV chassis TY.

if your dirty chrome /pc have issue don't post such rubbish... instate you write thanks...

this is trusted clean firmware for downgrade.. next time i will not response to any of yours post.

[betmen]

Re: Grundig 40VLE4421 - no picture

grundig TV with chassis TT use same firmware as your TV chassis TY.

if your dirty chrome /pc have issue don't post such rubbish... instate you write thanks...

this is trusted clean firmware for downgrade.. next time i will not response to any of yours post.

I dowloaded it with Opera...I don˙t know why are you angry.... I just told what hapened...nothing else, it is not

[dskall]

Re: Grundig 40VLE4421 - no picture

Got to love the language barriers on this forum. Easy to misunderstand each other.

[betmen]

Re: Grundig 40VLE4421 - no picture

My TV have sofware version TTGMR....V01.027.08 and TV does˙t have V+ key, programs can be changed only on remote, on TV is possible to change only volume.
This TV is driving me crazy, when it turns on everything works ok, but for that I have to bust it first with led tester or it want turn on without that.
Anybody have some idea, circuit diagram is in the first post.

[betmen]

Re: Grundig 40VLE4421 - no picture

Does somebody have some actual suggestion about how to try to fix this?
This forum is about that...I think

[thommyX]

Re: Grundig 40VLE4421 - no picture

There are almost 2 mistakes at Chassis Ty.
Defective mainboard or defective lighting.
The lighting is definitely to blame for you.
Your LED strips are called ZCC606 and these always cause problems when repairing them. Always exchange completely.
Any software that posts "diah" here is from my forum iwenzo.de
Your software is old, but has nothing to do with your mistake.
https://www.dropbox.com/s/omflqxh0a2...02.00.rar?dl=0
LG Thomas