Do I need to replace logic board or something else?

doctor2000

Hi John,

I have a MB134ll/a early 2008 a1260 mbp It spins the dvd the white light comes on for 3 seconds or so then cuts off no screen lighting. I took out the 2 ram chips 2gb each samsung and it beeped when powering on without the ram put one at a time in no beeps no boot up. It also charged the battery which only had 3 green lights to full. Do you think I need a new video chip or other part? If I need a video chip what type and model number do I need? I am retired and have the time to try the repair myself but your guidance is much appreciated.

Thank You
mike s.

John

Thanks for the post!

It definitely sounds like you're dealing with the common GPU issue. These machines also sometimes have a bad RAM slot, but as long as you've tried a single module in each slot and with the other slot empty, you've most likely ruled that out. In the beginning stages of the GPU issue there are usually lines or a checkerboard pattern, but the computer generally works, and then as it gets worse it gets to the point of no display at all, and a sleep light. I'm just curious, have you ever witnessed this machine working, i.e. was it a functioning laptop and then it stopped working? If you have never seen it working, then that makes me question whether you have good RAM or not. I would probably also take off the keyboard and jump the board...doing that will rule out keyboard issues.

I would really recommend either replacing the laptop, or buying a broken laptop with a good board on eBay, and then swapping boards. You can use the guides on iFixit.com for the swap. Replacing the chip requires significant experience and also expensive equipment such as a rework station. It's really not a do-able repair for people who don't do component-level board repair for a living. Personally it's not something I've ever done because it's a whole universe I just don't have time for.

That said, if you're still interested in replacing the chip, there is an interesting thread on this site called "MacBook Pro Nvidia 8600M GT replacement" (six posts down from yours) which has some detailed info on the various models of this chip.

Thanks, and good luck!

John

doctor2000

As far as your question John I just purchased this laptop I don't know anything about it. But I had a interesting thing just happen I took out both ram chips 2gb each and installed a chip from my HP G71 laptop a 1gb ddr2 800 pc2 6400 chip and it started to boot up the dvd drive spun up fans came on sounded like the harddrive was spinning up and the white light stayed on this time but no video what do you think John? Should I buy some new ram? Should I get video with the type of ram from my HP g71?
MIKE

John

No, I wouldn't put another cent into that laptop -- it's obvious it still has the GPU issue. The GPU issue comes and goes in its severity. It's possible if you don't power on the computer for a week it will boot up and be fully functional...for an hour. But it still has the problem and it's not going away. There is even a thread on iFixit on how to wrap the laptop in a blanket and force it to overheat, causing the GPU to work briefly:

https://www.ifixit.com/Answers/View/9045/MBP+A1226+Logic+Board+last+resort+fix+for+nVidia+video+chip

But again, ultimately it's a lost cause, and unless you have a rework station and are fluent with component-level board repair, it's just not worthwhile. The better route is to find a guaranteed-working board and do a board swap. And the better route than that is to buy a new laptop entirely, because these are a nightmare.

John