Thinkpads Forum

Hi I replaced LCD on my T61 and the backlight did not turn on. Later I fugured that inverter was not plugged in all the way or possibly with wrong polarity. I switthed it back but backlight is still out. Do you think I blew inverter or it could be something else (blown backlight, cable or system board)?

I switched LCD to another laptop - no problem so I guess I can rule out LCD completely, but obviously there is a problem with planar. I tried to reset it to defaults, disconnect CMOS battery - nothing. Any suggestions? Anybody?

I'm assuming that you swapped the entire lid assembly (LCD panel, inverter, cable, etc.) onto another system and the backlight works as normal. I'm also assuming that you've tried flipping through the output display settings via the Fn+F7 key combination (LCD, external, both) without any luck.

If that's the case, then there may be a blown fuse on the motherboard. I don't have any information as to exactly what and where those fuses look like on a T61 but here's a couple of them from a T23:

http://www.rkawakami.net/ibm_t2x/t23_mo ... _fuses.jpg (F9 and F12; battery fuses)
http://www.rkawakami.net/ibm_t2x/let.jpg (F2; main DC input, near the top of pic)

Essentially you are looking for parts labeled "F1", "F7", etc. and then you'll have to test them with an ohmmeter. Replacements can be found at places like DigiKey.com and Mouser.com but you have to know (or guess) what the current rating is, besides finding one that is the same size.

Yes I tried everything you described. So seems like I have to try to find those fuses somehow. OK i will try. Thanks for the advice.

Laptop went to repair shop . I will post findings.