Lenovo ThinkPad T430 - LCD replacement - only white screen.

[bpjl]

Hi,

I've got a Lenovo ThinkPad T430 laptop with a broken screen and a problem with the backlight.

I replaced the broken LCD B140XTN03.1 with LTN140AT28. Everythings should bo OK. However, when turned on, the screen only lights up in white. On the external monitor, the system loads and the computer works normally.

I will mention, that while the system is loading, the LCD blink black once - probably when the graphics driver is loaded. Backlight brightness adjustment works normally.

Is there something I can check on the motherboard or is it a defective matrix and should I exchange it at the seller for another one?

Or maybe the screen ribbon cable?

[rddube]

Re: Lenovo ThinkPad T430 - LCD replacement - only white screen.

Both questions you ask (defective matrix ? ribbon cable?) are probably close, but first I would like to see a very close photo of your connection to the LCD, probably not seated properly. A microscopic photo would be nice, but if you can't do that, inspect it with a jeweler's loupe and make sure it is seated properly and not damaged when you inserted it.

[bpjl]

Re: Lenovo ThinkPad T430 - LCD replacement - only white screen.

I checked the connection several times. Everything looks good. I decided to measure the voltages at the screen connector on the laptop motherboard (Lenovo T430 NZM4I-7 UMA VILT3 NM-A082):

PIN 2,3,4 - VCC3P = 0V
PIN 5 - VCC3B = 3.3V
PIN 30 - VCC3P = 2.88V
PIN 35,36,37,38 - VBL20 = 19.9V

Following the missing voltage on pins 2-4, it turned out that on one side of fuse F3 I have 3.3V and on the other side 0V.
After the test short circuit, the screen start working.

I replaced fuse F3 and the problem was solved.

[rddube]

Re: Lenovo ThinkPad T430 - LCD replacement - only white screen.

Good job. Glad to hear you solved it!