Screen distortion after logic board repair

[geekdad]

Hello,

I've been doing MBP board repairs for a while now, reball and component/trace/pad replacement. I have an odd issue which I haven't had before. I'm hoping someone else has seen this issue.

It is a 15" 2008 MBP. I originally repaired 8 months ago for a no video issue. My notes indicate I reballed the GPU and North Bridge. This fixed the no video issue.

The customer returned the unit to me with this new distortion issue (see attached). I am trying to determine what has caused this. Did I have a bad repair or a new failure issue.

Thanks,
Adam

 

[duervo]

If the issue persists on an external monitor then I would start peeking at the LVDS cable as the possible cause next.

In fact, I'd probably suspect the cable first before anything else.

For example, if you take a monitor and slowly plug it in to a PC's video card, there will be a certain point at which the pins begin to make contact with the contacts on the video card. In some cases, I've been able to get the display to look very similar to what you show in your posted pic when the cable is not quite plugged in all the way (meaning only some of the pins in the cable are making contact.) The same thing has happened to me when I use a monitor temporarily, and as such plug the cable in without screwing in the retention screws on the cable end. Sometimes, the cable can come loose in that situation, causing similar affects to that shown in the pic.

So yeah ... I would suspect a wonky LVDS cable first. Not uncommon for them to wear out in a system where the display has been opened and closed over and over again in the span of 5 years.

 

[nickandre21]

is there a no battery sign as well there?
Well do check the connections at first if not then try reballing again. I wished apple would have done something more better for the 2008macbook pros.

 

[geekdad]

Very late follow up I know... but I wanted to let everyone know what the issue was.

It was the GPU itself. It had failed. When I replaced it with a new one the unit worked fine. I have since tried using the GPU I removed on other boards, and it is definitely failing... the screens always look distorted.

Thanks,
Adam