LED JVC LT-40N530A half screen black.

[MegaZAC]

Main:
tp.sis231.p83

T-con
KSZ80_OB_S4LV0.2
E88441

T-con has:
rt6503a
bm81204 317 h56
AMLCD LQF6041T0B-01

First, it had stripes on the right side. Pushing the top corner changed them, but not removed. I disassembled the TV, and since that all that side is black without stripes.

I checked a lot of suspicious things. Found that no matter where I push there will be no stripes anyway. Seems, there are different issues.

Found dodgy voltage INV_V randomly jumping from 1.4 to 1.8V on T-con. But I also not sure that the main board is fine.

Also, on the problem side of T-con there is no negative 7.5 volts, not sure it by design or a bug.

Any ideas?

[MegaZAC]

Re: LED JVC LT-40N530A half screen black.

Still no ideas?

[budm]

Re: LED JVC LT-40N530A half screen black.

Show us the screen shots of what the image looks like on the screen.

[MegaZAC]

Re: LED JVC LT-40N530A half screen black.

[Diah]

Re: LED JVC LT-40N530A half screen black.

since you had the tv disassembled. its much like you damaged one of the LCD glass corner which always had VCC thin film line .. go back and inspect the end glass of the LCD

[MegaZAC]

Re: LED JVC LT-40N530A half screen black.

All corners are perfect. From outside the whole panel has no damage at all.

[nomoresonys]

Re: LED JVC LT-40N530A half screen black.

Looks like you have been pretty thorough, did you check the little ceramic caps on that driver board for shorts or low ohms? I would be suspicious of any reading less than 100 ohms.

[MegaZAC]

Re: LED JVC LT-40N530A half screen black.

There are no shorts anywhere on both boards, checked by multimeter + thermometer. However, it may be inside the panel.

Ceramic caps have low capacity, but that seems normal for em. The biggest show open wire, medium show 20-60 kOhms, and the lowest measured value is 560 Ohm on the 102 1kv capacitor following the main inductor. Not sure that this is a proper value, but I would expect different issues if this one would be the root problem.

[Diah]

Re: LED JVC LT-40N530A half screen black.

could you please upload photos on the LVDS socket at main boards and the area around from both side,, there should be R or F1 for VCC

[budm]

Re: LED JVC LT-40N530A half screen black.

https://www.badcaps.net/forum/attach...9&d=1601724264

Can you show us the whole length of the board and also the pictures of the whole backside of the TV showing all the boards?

[MegaZAC]

Re: LED JVC LT-40N530A half screen black.

LVDS is 40-pin, unplugged for better view. Not sure about R or F1.

[Diah]

Re: LED JVC LT-40N530A half screen black.

this is JVC TV !!! its Chinese DIY TV LOL
you need to take out the LVDS complete out from this DIY and sitting at comfort place and start with yours DM Beep Ton to test all pins from MB side to the end of ribbon cable which it goes to the panel socket.

[MegaZAC]

Re: LED JVC LT-40N530A half screen black.

T-con in good res

https://freeimage.host/i/26oVMx
https://freeimage.host/i/26oW6Q

[MegaZAC]

Re: LED JVC LT-40N530A half screen black.

test all pins from MB side to the end of ribbon cable which it goes to the panel socket.

Done, all pins work fine.

[Diah]

Re: LED JVC LT-40N530A half screen black.

for me i am sorry.. out of any idea for this Chinese DIY
the only things i do know.. they sell this All IN ONE DIY TV boards on web

[nomoresonys]

Re: LED JVC LT-40N530A half screen black.

Maybe try hitting all the boards driver board included with a hairdryer, warm it up kind of toasty and see if there's any difference on display.

[budm]

Re: LED JVC LT-40N530A half screen black.

https://www.badcaps.net/forum/attach...0&d=1601724264

Did you check the resistance of those MLCC (Multi Layer Ceramic cap) in that section to see if any of them show low resistance reading, I.E. <100 Ohms?

[MegaZAC]

Re: LED JVC LT-40N530A half screen black.



Checked all, found 3 groups below 100 Ohms. From left to right:

1) 0 Ohm, both signed as test
2) 44-45 Ohm each.
3) 10 Ohm each.

There is nothing like a single broken one. Either whole group is broken, or fine.

[nomoresonys]

Re: LED JVC LT-40N530A half screen black.

Measure just the capacitors, skip the resistors for now, the caps have a C by them on the board.

[budm]

Re: LED JVC LT-40N530A half screen black.

Checked all, found 3 groups below 100 Ohms. From left to right:

1) 0 Ohm, both signed as test
2) 44-45 Ohm each.
3) 10 Ohm each.

There is nothing like a single broken one. Either whole group is broken, or fine.

You tested the wrong the parts.
C = Capacitor