09-14-2009, 08:40 AM

Ok, so I'm working on resurrecting an old iBook (G4 A1133 1.3ghz 12") and turning it into a multi touch computer. My original plan was to just jack the lcd, but soon realized that it wouldn't work. So, I thought I may as well just make the whole thing multi touch, instead of just making a multi touch monitor.

This thing is old, but was a trooper for years. The case got cracked at some point, and this led to eventually the screen dying. Not the inverter or the backlight, mind you, just the lcd. It powers up, stays white, and does nothing else.

For a long time, this could plug in to an external and run just fine, and that may still be the case, but I haven't checked.

I've got this thing wide open, at the moment I'm basically just running the logic board, I've taken off the case and everything I could. Right now the only things plugged in are the HD, the inverter, the lcd data cable, and the piezos so I can click the on button. Occasionally I plug in the keyboard to try different ways of starting, all to no luck.

Does anyone out there know of a pretty solid way to deduce the issue? My gut instinct was that it was the data cable. I checked it out, and sure enough, the data cable was frayed under the sticky fabric crap. I took the 2 frayed wires out of the bunch, made sure they weren't touching, and tried, but no love. just white.

So, figuring it was the cable, I popped off that lcd and backlight, and plugged in a screen from a G3 12" A1005 700mhz, and found that the data cable would actually fit in to the board of my g4. the cable was different at the top connection, but I tried it in the G4 lcd first, fail, then tried just plugging the g3 lcd in, also with no luck.

So this makes me think that maybe it's a graphics card issue? This is a later model than the infamous graphics issues had by G3s and 4s, but I even looked for the chip, and this board doesn't have it in the same spot.

I've inspected both sides and can't seem to find any issues with the board, but have pretty much ruled out any other problems. Is it possible that the chip that is sending the image just flaked out? This seems to be so obviously the data cable, but is it possible that I could reproduce the same issue with 2 different sets of cable/lcd?

Any clues? I'd love to get this thing going, I'm just a few hours away from a DIY lemur here, and I'd hate to have to start over with a monitor...

09-14-2009, 08:47 AM

ooh, also, I got it going in target disk mode, so I know the board is at least partially functional. I'd maybe consider the reed switch, but that doesn't make sense, it seems like the monitor wouldn't turn on at all. I'll try plugging that in, who knows.

Also, in a feeble attempt to increase the FOV on a webcam, I snagged the lens from the disc drive, and accidentally mangled the thing while I was at it, so no booting from disc for me. I tried every combination of holding down keys (Pram, Power, disc mode, option, shift, etc, etc), and nothing worked except target disc mode and assumedly the PRAM, it would reboot like it's supposed to.

09-16-2009, 03:05 AM

No love?
Another update:

got my hands on an old mini dvi to vga, and managed to boot it up, everything seems to be working just fine. So, maybe this is the infamous video chip issue after all? Can't seem to find a diagram for the g4 LB, but maybe one of you has another idea?

09-17-2009, 01:55 AM

Sounds like fun.

I used iBooks at my school 3 years ago. They all were soooooo slow...

Good luck with your project.