[craigymusic]

I was given a 1.33 Ghz 12" iBook. I have been working on it for some time. The start up chime sounds, the usual whirring sound happens and then it either boots normally, or stops at a black screen at that point. It is quite random. I have changed the hard drive, I have tried two different logic boards: it still happens. The only other repair I have done is to repair the display cable. The repair involved finding which wire in the cable (of 4) was broken and soldering a new one in it's place and then re insulating it with tape. When it boots the display is perfect, all the ports work, the screen does not flicker if the lid is moved etc. I have taken out the extra RAM, and just used the built in RAM...it makes no difference. I don't know what to do next.

I should add that there is no video out if the computer stops at the black screen point- I suppose it has not booted up so it has not got to the point of powering up all the ports etc.

I have tried different batteries, and two different power adapters as well. When I say Random I really mean it is Random.

Thanks, in advance!