Video hardware problem

[dakels]

friend of mine dropped his laptop (powerbook G4 17").

Ever since then the screen has shown very bad artifacts. I'm trying to find a resolution without paying $1200 for a new logic board. The warranty is expired (3 years).

You can see here what the artifacts look like. This is a direct screen shot taken from the damageed laptop. The actual screen shot shows the artifacts too...

This covers the entire screen at almost all times. The strange thing is that hooking up a extrenal monitor still shows the artifacts. Whats even stranger (to me) is that a screen still shows the artifacts. I would have expected the signal to be interfered with resulting in a clean external connection or at the least a clean screen shot. I am assuming that something is wrong with the video processing before it sends that data out to the screen. If you press on the laptop at certain times the artifacts will go away. Sometimes it goes away on its own for a short time. Whats even stranger is that sometimes a directory window or application window will not have any artifacts while everything else including the background does.

I have tried some simple things like disconnecting and reconnecting the internal RAM and video cable to the LCD. Also blew out some dust. Some chafing damage was visible to the video cable leading to the built in LCD. Other then that I couldn't see any outward damage.

I'm looking for some advice on how to break down and understand this issue.

- What is the last source of hardware to recieve the video image for a screen shot? I assume it is processed by the video card then sent back thru the AGP bus.

- If pressing on the case can temporarily solve this issue, then I would think it could be a connection issue? With the screen shot showing the artifacts, I would assume we arent talking about the video out signal but rather the AGP bus connection? (possibly?) (might be soldered)

I'm really hoping a loose connection could resolve this issue over a $1200 logic board replacement which at that cost would merit a new laptop altogether.

I'd appreciate any insights.

 

[Kaervak]

Looks like the fall managed to loosen the BGA video chip. It's possible that the logic board was part of the batch that had the recall and it was fine until the fall. What you can do is a little weird, but has been shown to work. http://geektechnique.org/projectlab/726/diy-obsolete-ibook-logic-board-repair Keep in mind, that is an extremely easy way to destroy what's left of the powerbook. What you could also try is see if any local electronics repair places are able to reflow boards and let them deal with it. There's also a seller/service shop on eBay that specializes in reflowing apple laptops with this problem. I don't remember the exact price, but I think it's under $100.

 

[TheStu]

You can check out ifixit.com for all kinds of replacement parts for it as well. They often have pretty much every part that goes into the older apple laptops... so if it turns out to be a cable issue, you can check there for that... or the logic board... or the screen... or the case... tons of stuff

Anyway, I would follow Kaervak's advice about checking out the BGA... That is the most likely culprit

 

[dakels]

Thanks for the replies. It really help me find a direction. I didn't know all this info was out there but now I know what to look for. I'm going to try a thermal pad for pressure and see how it works for a little while. Then move to the incredible looking flame solution But not until the person is totally ready to purchase a new laptop which I think he is going to do anyways in a month or so.