[Koralatov]

So, thanks to the efforts of the posters in my previous thread about my seemingly-dead Pismos, I have two functioning laptops. I’ve only extensively tested one of them, and it seems to be running fine. However, if it’s left sitting for any length of time, it tends to freeze. Everything appears normal, but it doesn’t respond to input.

It’s currently missing the heat shield that sits above the processor. I have two on the way, though, so that should be fixed shortly. However, when I was installing RAM in the bottom slot, I noticed that it’s missing a screw from the heatsink assembly, and, perhaps more problematically, the thermal paste on the processor is dried up.

As I don’t have much experience in Pismos, I’m not entirely sure whether this is what’s causing the problem. I suspect it is. Anyone with more experience know how if reapplying new thermal paste and installing the heat-shield would be enough to fix this issue? I might also be able to scavenge a screw for the other side of the heatsink.

Any and all input much appreciated!

[Koralatov]

Just a quick update. I came across a thread on the Apple Support Forums about replacing/reseating the processor on a Pismo, and one of the posters makes mention of reapplying the thermal paste. I think this might be my best bet to solve the freezing problem I’m facing. However, I’m slightly concerned about the razor-blade technique. Is there a better/safer way of removing the thermal paste? Isopropyl alcohol seems to be the recommended material for the job. Can I just use a Q-tip to swab it off, or do I risk overloading the processor with static electricity?

[seanc]

Have a look for thermal grease removal liquid. Just use a lint free cloth and it'll come right off.
As for reapplying it, I just stick my finger inside a plastic bag and rub it around or fold up some paper to spread it as evenly as possible.

[Koralatov]

Originally Posted by seanc 

Have a look for thermal grease removal liquid. Just use a lint free cloth and it'll come right off.
As for reapplying it, I just stick my finger inside a plastic bag and rub it around or fold up some paper to spread it as evenly as possible.

As always, thanks for the input. You seem to be coming to my rescue an awful lot these days! (That said, it is appreciated.)

I’ll give reapplying the thermal paste a go and see if that fixes the freezing issue.

[Koralatov]

Okay, so I've reapplied the thermal paste, after cleaning off the old, fitted the heat shield and it's definitely running much cooler. I also made sure the processor was firmly seated. However, it still freezes if it's left for more than a couple of minutes without doing something. I checked the System Profiler, and it registers the L2 cache as being there, which would seem to rule out a dead cache (which I read somewhere on the interweb may be causing the issue). As such, I'm really beginning to run out of ideas as to what could be wrong with it. Any ideas?

[tinkered]

Are you sure it is CPU heat and not ram or damaged HD cable, which can be harmed by heat? Have you reseated everyting and tired booting from a firewire drive.

[Koralatov]

Originally Posted by tinkered 

Are you sure it is CPU heat and not ram or damaged HD cable, which can be harmed by heat? Have you reseated everyting and tired booting from a firewire drive.

It’s not the RAM; I’ve tried it with various different RAM configurations, including some known-good RAM, and it still froze. The hard-disk cable is an interesting point though—I hadn’t considered that it could be that. Luckily, I have a couple more from the two other Pismos I have, so I’ll try swapping it out to see if that improves the problem. I’ll also boot it from a FW drive to see if that solves the problem.

Many thanks for the suggestions!