R61 lcd issue - very dim with good panel and inverter

[rutteger]

Having issues with the display on a recently purchased Lenovo R61. Machine type is 7732 a WXGA 14.1 wisescreen and intel graphics chip.

The LCD is very dim as if the inverter has failed. Have tried another screen and a known good inverter - same behaviour. The inverter from the R61 has been tested in another machine and works fine. Further the only LED on the inverter board to light in the wireless one - all others are now permenantly off. Display on external works fine. Guess this points to the motherboard or LCD cable. Problem similar to this experienced here > http://www.thinkpads.com/forum/viewtopi ... 29&t=77455

The machine was purchased with a cracked LCD and a few other missing parts. Replaced the lcd with a good one and had it working fine.

Whilst the bezel was off added a BDC. Had a few issues with BDC installation (although that's the least of my problems now ) so took the card off. Unplugged it but forgot to remove the battery (I know ), after this the problem started.

Looks like the inverter isn't getting powered properly. Guess either LCD cable (I wish) or more likely something has failed on the mobo. Are there any user replaceable fuses on there?

[rutteger]

Laptop now stripped down.

The 'main' LCD fuse F7 would appear to be good. However a second smaller fuse (unlabeled) by the LCD connector on the mobo appears to have failed. More testing required though. Not sure whether to short it out and test or wait for the incoming LCD cable...

[richk]

If the fuse blew, something is wrong. Did the display ever work? A wrong panel or bad inverter can cause it. I've never seen it caused by a cable.

[rutteger]

If the fuse blew, something is wrong. Did the display ever work? A wrong panel or bad inverter can cause it. I've never seen it caused by a cable.

When I bought the machine the original IBM LCD worked fine - it was badly cracked though.

Replaced it with a supposedly matched generic LCD panel off ebay. This also worked fine for a couple of days.

The inverter is good.

Assume I damaged something on the mobo by pulling the BDC with the battery in.

Agree it's unlikely to be the cable. Will hang onto it for a few weeks to see if I can pick up another mobo cheaply, more likely will just part it out and rue my mistake.