I replaced the fan in my X61 yesterday, and it works great! Unfortunately I noticed that after the repair the indicator lights at the bottom of my screen no longer light (except for wifi and bluetooth).

What do I need to replace to get them working again?

The symptoms sound like a blown motherboard fuse. Did you have the machine unplugged and battery out before you started?

Absolutely, yes. I'm sure because I had to remove the battery to get to one of the keyboard screws...

Beyond that, it is hard to diagnose from 3000 miles away

Hi Spirit of X21!

It looks like you need to replace the 'LCD inverter card', however are two versions of it: Foxconn and YEC.

You can find more information about it HERE.

Just navigate to 'Parts list' -> 'LCD FRUs' on the left and take a look at the LCD breakdown diagram. You will need part number 11.

I'm willing to bet either or would work just fine. Or you could take the LCD bezel off carefully and then the inverter and take a look at the part number on it.

Hope this helps!