[ltlasset]

I have 4 powerbook g4 12' 867mhz logic boards.
Two are U200 G10D4, and two are U200 G10C4 as per the sticker under the ram slot.
The problem is with the two G10C4 boards. Both show a screen image, but no backlight.
The backlight inverter is good and tested.
I found a previous post on the boards about the fuse at F1 on the board, which when bypassed might make it work.
I tried this and the boards now work, showing video+backlight.
BUT.....
I dont know what rating fuse to replace the blown one with at F1.
AND....
On the back of the two boards at site C3, which is close to the connector for the inverter, it appears a capacitor may have been there, and could have blown off, possibly when the fuse blew.

The capacitor is present on the G10D4 boards. Does anyone know if the capacitor is supposed to be there on the C boards? Or is this just a revision difference? I don't want to spend the time getting them fixed and then have them blow again.

My questions are:
Does anyone have closeup pictures of the back of a U200-G10C4 working logic board?
Does anyone know what rating fuse goes at site F1 on these boards?

Thanks,
Landon

*update*

I have searched long and hard for some detailed board pics.. and haven't been able to find any. If anyone has some please post them for me.

[ltlasset]

*bump*
still hoping someone has some information.

[ecotton]

TH = a thermal fuse. It is supposed to reset itself once the fault or the temporary power surge has passed... But if it is overloaded repetitively (your keyboard gets temperarely jammed or you cycle the brightness up and down to fast) it overheats too much and goes open circuit forever...

Thermal fuses are usually calculated with wattage being the selecting factor over current in a normal fuse.

Say your display has a 5W lamp in it - use a 7W thermal fuse or replace with a normal fuse that will take 7Watts of power at the voltage being supplied to it.. i.e watts = voltage X current

fuse = current = watts/voltage

7/12v = 0.6 Amp FUSE!! OR CLOSEST VALUE AVAILABLE!! Maybe a 0.5Amp Fuse

Hope this helps,

Eric.