ibook disp/14/4 vram error

I have a 500Mhz dual usb ibook. When booting OS X it hangs just when the blue screen appears. Hardware test shows a "disp/14/4" vram error. I've reset the PMU, gone to OF and reset the nvram, etc... Any ideas before replacing the motherboard? Thanks, Ramon -- G-Books is sponsored by

ibook only works with battery

Hi, My ibook (snow 500Mhz, dual USB) only works with the battery. When plugged to AC adapter, the amber light blinks, but gives no power to boot and battery won't charge. I've checked the power board and seems to be ok. Can someone give some idea before replacing the motherboard? Thanks, Ramon