early-2008 Macbook Pro beachballs exactly 1 hour after turning on

[oxfordguy]

My early-2008 15" Macbook Pro (see signature for specs) has recently started beachballing and becomeing unresponsive exactly one hour after the machine has been switched on. It does this every single time, so the machine can no longer be used for more than an hour.

I have not changed the spec of the machine for more than 3 years, but this issue has only started occurring this year.

I have had the machine looked at my our local Apple Reseller, who did a hardware test, but they could find nothing wrong with it. I've also wiped the disc and done a fresh install of OS X 10.9, but still get the same problem. It's very strange!

NB: the main motherboard was replaced (for free) about 3 years ago (due to something faulty with the graphics) and the keyboard, battery and harddisc have all been replaced (the latter with an SSD), as was the RAM (up to 6Gb), so many of the components are not as old as 2008!

Does anyone have any idea what might be wrong, or experienced any similar problems?

 

[Potatochobit]

when it heats up something stops working
common in USB hubs that need to be replaced
not sure about your mac though

try testing the memory first before booting into OSX

 

[oxfordguy]

when it heats up something stops working
common in USB hubs that need to be replaced
not sure about your mac though

try testing the memory first before booting into OSX

It's strange, though, as it seems to make no difference how hot the computer is for how long it takes to lock up - I could be running the computer at 100% CPU for an hour or it could be completely idling for an hour, but in both cases it will lock up after exactly the same time period.

I've tried re-seating the memory a number of times, but this seems to make no difference. The Apple reseller I went to also tested the memory and said it was fine!