[inigopete]

I've got a TiBook 550 (Gigabit ethernet) and after lending it to a friend, I got it back this morning and the screen's very very dark, as if the backlight is off, on any setting.
What to do? Is it the inverter board? I've tried resetting PRAM, did no good.

: P

[Xaositect]

Reset the NVRAM:

Boot holding CMD-OPT-O-F

at prompt enter:
reset-nvram (press enter)
set-defaults (press enter)
reset-all (press enter)

the computer should say ok after the first two, and a couple lines after the third before it reboots itself.

If that doesn't work, and you know your way around a multimeter, test the voltage coming out of the inverter. If you have good voltage, the backlight tube is bad. If you have no voltage, the inverter is bad.

Replace appropriate componenet. If it's the screen, you will probably just replace the unit. For parts try preowned.com or Southern Computer, or a local shop if one will sell you the parts.