PowerBook G4 12" 1.5GHz, stripped heatsink screw... Possible Solution!

[Snial]

Hi folks,

Back around 2016, my beloved PowerBook G4 12" fell off a table and the inner pin from the PSU cable broke, falling into the PBook's case. I took it apart to remove it, which was successful, but when reassembling, I found the LHS heatsink screw was stripped.

(I marked half the top to prove it wasn't spinning instead). I think I may have a possible solution. It's crude. I think that I can construct a metal brace running along from under the frame at the right-hand edge of the heatsink to under the frame at the LHS screw, because it's possible to fit a piece of metal under there.


The key thing IMHO would be to prevent the brace from buckling while pressure is applied equivalent to that of the original bolt and also be able to adjust it. Any ideas?

The second thing is to remove the thermal paste on the CPU before getting some more and reapplying the right amount correctly.

How do I do that?

-cheers from Julz

 

[Snial]

OK, I think I've figured out a possible solution to the first issue. I could place small washers on the LHS screw, but below the brace so that I can adjust the force on the heatsink.

 

[Froggy814]

Can you use a tap and die set?

 

[Snial]

Can you use a tap and die set?

I have thought about that, but the screw is only about 1mm, maybe 1.5mm in diameter ( would have to check). But I don't have a tap and die set. My Dad does, somewhere, but it'd be hard to dig out I think.

 

[Froggy814]

Okay, that is really small. I hope you can fix it.

 

[obsolete]

I think I see what you're suggesting and it might work, but how are those studs attached to the board? Is the whole thing soldered into the board, or is there a nut soldered into the board that the stud is threaded into? If the latter, you may just be able to replace it, but you would need to fully remove the board to find out.

The second thing is to remove the thermal paste on the CPU before getting some more and reapplying the right amount correctly.

How do I do that?

-cheers from Julz

I like to use a plastic or wooden tool to scrape most of the old paste off; both are too soft to harm the die or substrate. Follow with paper towel and isopropanol for the remaining residue, and some compressed air to blow away dust.

 

[herd]

Those screw studs are attached to the logic board with solder. They tend to creep and pull loose over time anyway, so if it already needs to be replaced, I would suggest adding a screw(s) from the back side of the PCB. You could apply a little glue to keep it from turning, but the tension from the heatsink spring would not stress the glue as it does the OEM solder joint. Even tension from the two springs is more important than extreme force. I've seen a few cases where one screw would pull free, and the tension from the other would lever the heatsink at an angle that opens an air gap and greatly reduces its effectiveness.


forums.macrumors.com/threads/powerbook-g4-12-maintenance-servicing.2243978/

 

[obsolete]

Ah, good pictures in that MacRumors thread. Yeah, desolder, replace with screws. That's the way.