Thinkpads Forum

I recently upgraded the display on my T500 from the 1280x800 panel to the 1680x1050 panel however when i installed the display and booted the machine the backlight stopped working but I could make out the faint lenovo logo. When I went to reseat the ribbon cable and inverter it stopped displaying an image and the status LEDS also stopped working and when I connected to an externel monitor it only recognised the monitor.

I have tried two different ribbon cables and two inverters however they all produce the result above. I know that this could be an issue with the fuses being blown however I dont think this happened as the battery was disconncted during the process and there was no flash from to the screen to indicate a blown fuse. It is also not an issue with the panel as I swapped back in the old display but it produced the same problem.

I am creating this posts to see if anyone has a solution or has encountered the same problem and would be able to share their thoughts as to how they resolved the issue.

Maybe you changed from a CCFL screen to a LED screen.
In that case you also need to change from an inverter card to a LED control card.
See the HMM for details/part numbers.

I'm not sure I dont think that is the case as they only made the 1280x800 in LED and mine was not.

Your reply makes no sense...

In my opinion it seems most likely something on the board failed, could be fuses. Fuses are replaceable. I agree it should not have happened because power was disconnected, I have no belief against your due diligence. I blew up a T540p once even tho the power was disconnected, the caps were still charged, I thought I’d drained them but I guess not

Things happen, unfortunately.

Tested the fuses with a multimeter today and they seem all good. I'm just going to order a new inverter board and hope for the best.

JC8686 wrote: ↑

Tue Mar 03, 2026 4:05 pm

Tested the fuses with a multimeter today and they seem all good. I'm just going to order a new inverter board and hope for the best.

Yes agreed, I would try a new inverter board.

TPFanatic wrote: ↑

Sun Mar 01, 2026 2:28 pm

In my opinion it seems most likely something on the board failed, could be fuses. Fuses are replaceable. I agree it should not have happened because power was disconnected, I have no belief against your due diligence. I blew up a T540p once even tho the power was disconnected, the caps were still charged, I thought I’d drained them but I guess not

Things happen, unfortunately.

yea agree - a fatal flaw in the T400 model occurs when the lcd cable shorts and blows the fuses beside the lcd socket on the mb... maybe this is also the case here
this t400 fatal flaw is very common as i learned