W500 no backlight

[Bibin]

My W500 was working great last night, and this morning the backlight will not come on. I can see the image. I tried both my LCD panel (Samsung 1920x1200) and a 1680x1050 panel. Both light up in a friend's laptop.

I replaced the inverter, checked connections, both fuses near the LCD connector are fine according to my multimeter. Any other ideas?

[RealBlackStuff]

Check the BIOS/Config/Display and change the Switchable graphics to Discrete or Integrated and the OS to Disabled.
Temporarily use an external monitor to change those settings.
Then fully switch off and boot afresh.
No guarantee but this works on a similar T500.

[Bibin]

Whoops, realised I posted this W500 question in the T500 forum, but they are more or less the same computer.

I fixed the problem. I dug a little deeper and removed the Wi-Fi card. Underneath the black plastic covering the connection to the RJ-11 plug is the fuse labeled "F7" with a 'P' on it. This fuse had gone open. For now I bridged it, and will replace it once I have found what it is supposed to be. My backlight is back, though.

[RealBlackStuff]

The fuse is the same as fuse F7 on a T60 motherboard.
Available from e.g. here: http://www.newark.com/littelfuse/046600 ... dp/86H2954
FYI: the fuse-picture is for illustration only!
In real life those fuses have a P printed on them.

[precip9]

Is the fix usually to just solder the new one on top of the old one?

[Bibin]

Is the fix usually to just solder the new one on top of the old one?

You can do that, it's electrically fine, but there isn't really a gain to it and it can make it less clear what work was done (the parts are small!). Removal isn't hard in this case, it's worth doing.

Thanks for the part reference, RBS.