Author Topic: Damaged laptop LCD panel - what may have happened?  (Read 452 times)

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Offline Koray

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Damaged laptop LCD panel - what may have happened?
« on: September 14, 2022, 11:42:45 am »
Hi there,

I received a Thinkpad T450s laptop with a non-working display. I tested the mainboard with a known good display/cable combo, no problem there. Then I tested the LCD unit with a known good data cable, it works, too. So I decided that it was the cable that was faulty, and ordered a new one from Aliexpress. The new cable looked good, I connected it, and the laptop worked fine. I put a new OS on the machine, updated it and turned it off. The same evening I removed it from my bag, turned it on, and nope, backlight comes on and no image on LCD. Tested again with known good cable, no image. Tested the aliexpress cable on another screen, it works, cable looks OK.

I then tested the new Aliexpress cable and found out that the metalized cloth tape that grounds connectors to each other is not complete, so the ground planes on the LCD was not properly connected to the ground on the mainboard and the shielding around the cable was missing for 2cm towards the end of the motherboard connector.

Now the LCD will not work at all, backlight comes on, the fuses are OK, there are various voltages on the LCD board, but the LCD is always dark. It is a pity since the unit is a very high quality copy.

Could this damage be a result of ESD damage? Maybe evil sparks during removal from the nylon cloth laptop bag? Is there any chance or way to revive the unit? Some photos attached (have no idea if they would help or not).

Thanks in advance!

Koray

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Offline m k

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Re: Damaged laptop LCD panel - what may have happened?
« Reply #1 on: September 19, 2022, 12:04:00 pm »
It can also be either LCD or motherboard connector.
When you connect it, it will work for a moment.
Advance-Aneng-Appa-AVO-Fluke-General Radio-H. W. Sullivan-Heathkit-Herbert Arnold-HP-Kaise-Kyoritsu-Mastech-Simpson-Tektronix-YFE
(plus lesser brands from the work shop of the world)
 

Offline Koray

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Re: Damaged laptop LCD panel - what may have happened?
« Reply #2 on: September 22, 2022, 06:57:10 pm »
Thanks for the reply. Motherboard works OK with another LCD, but I will definitely check the LCD-side connector.
K.
 


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