Extremely Odd iBook G4 Display Problem.

[sjword]

I've got an iBook G4 that has a display problem that has me completely stumped. When turned on, it chimes and all is well, but then the screen flickers almost like a lightbulb does right before it goes out. After this, the display works but is dark, as if the backlight has gone out. Well, no problem, I thought. I swapped the display from a G4 with a bad logic board to this one and, wait...the same thing happens? Both displays work (turn on, backlight works, etc) when installed on the G4 with the bad logic board, but neither work on this one with a perfectly good logic board (or so I thought). Could the port itself on the logic board go bad, or cause the display to flicker and the backlight to not work correctly? I was going to attempt to replace the backlight or inverter cable, but then I remembered that the display works fine on the other iBook, so I decided against it since it's so tedious.

I am stumped and have no idea where to go from here. As it stands, I've got two G4 iBooks that I would love to piece together into one working one, but I can't figure out this darn display problem.

Any help appreciated!

 

[tomlee59]

I don't know about the ibook g4, but if it's similar to the g3 version, the backlight inverter gets its power through a power MOSFET switch on the logic board. If you've already swapped complete lids and the problem remains, then the likelihood of this component being the problem increases greatly. IIRC, it's a six-pin surface-mount DIP. You can trace to it from the 4-pin (I think it's four) connector that goes to the lid/LCD assembly. DigiKey sells replacements quite cheaply.

 

[sjword]

I don't know about the ibook g4, but if it's similar to the g3 version, the backlight inverter gets its power through a power MOSFET switch on the logic board. If you've already swapped complete lids and the problem remains, then the likelihood of this component being the problem increases greatly. IIRC, it's a six-pin surface-mount DIP. You can trace to it from the 4-pin (I think it's four) connector that goes to the lid/LCD assembly. DigiKey sells replacements quite cheaply.

What's required to replace this part? Do I need to have soldering skills, i.e. is it permanently attached the to logic board? I will read up on it and see (and hope) if that's the problem! Thanks for the reply!