PTherapist wrote on 2021-05-31, 12:41:
Now that you've tried various different things to hopefully loosen it up, have you tried installing the CPU back into a motherboard, lower the latch to lock it in place and then twisting the heatsink left & right? That usually works for me, but of course you have to be careful not to use too much force and wrench out the CPU from the socket.
Well, after soaking in acetone, soaking in alcohol, boiling, freezing, boiling again (well, dropped in freshly boiled water), various mechanical attempts at twisting and tapping, I finally took it out of the freezer and took the desoldering heat gun to the heatsink. After it was piping hot, I used a rag to hold it and twist the CPU, which finally came off with a minimum of pin bending.
It turns out to be an Athlon 64 x2 5050e, 2.6GHz.
I put it in the "test" box, I have an Intel board on my test bench to test hard drives (the 500 and 640 were dead, the 320 and 1000 survived). I have to decide on that system - it's a Studio XPS (the budget XPS) i7-920. The case is missing the side panel (a recent theme with me, I got 3 in a row like that for some reason). It's also not a desperately pretty mini-tower, but it's light and has 6 DDR3 memory slots (but only PCIE expansion slots, 1 16x and 3 1x). Nice little heatpipe cooler, though.
Also, as it turns out, the Radeon 4850 is fine. Runs a little warm, but it's a 4800 series, my 4890 is an absolute space heater.
BitWrangler wrote on 2021-05-31, 12:52:
I'd be looking for a flat steel "bicycle spanner" type wrench to see if I could engage the heatspreader and apply torque.... failing that, I'd try to put it in a vice with shims that gripped the heatspreader instead of the CPU substrate. Then twist again, like you did last summer...
Well, I basically decided against making or buying a tool just to get *one* heatsink off. Were I to have a cottage business in refurbishing hundreds of discarded 2000s machines I would probably come up with a tool, and I bet that would have been over two days earlier. 😀