Powerbook 180c Video Issues

[joe4227@sympatico.ca]

This machine is new to me, from eBay.

The screen seems to flash between full and half height, and the image ghosts in both halves (upper hal and lower half).

Moved the display back and forth, doesn't seem to be the cable. Also inspected inside the LCD. Nothing obvious.

First question - does this sound like the Active Matrix Display itself, of more like a problem with the video controller. That will a Chips and Technology controller, not sure which yet.

This machine is much more complex in terms of boards and cables than the 150 was!

I have the "Service Source" and the Dev notes, but nothing obvious there. Most issues with this (Sharp LQ9D011) active matrix colour display refer to bad pixels, etc.

If this were a CRT, I'd be looking for Horizontal Sync problem. What would the equivalent be in this technology?

I bought this machine because it has ADB, and allows an external monitor to be connected. I have to find the right cable first before I can do that!

 

[Byrd]

Once you have checked the motherboard video cable, and the ribbon cable to the LCD, check the inverter next. I just fixed a PB540c with very similar symptoms (exactly 50% of screen with lines/minor artifacts, bottom half perfect) by replacing the inverter with the same part from a PB520 greyscale model. This surprised me too, as the fault looked very much like a faulty video controller/bung ribbon cable(s).

 

[insaneboy]

if the grayscale part works... I think I'll be parting out a 180 with a perfect screen soon. I doubt it's going to sell on fleabay(doesn't start up anymore)