VOGONS


First post, by smoke86

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Hi,
I recently bought a Pentium 1 CPU that was supposed to be fine. It turned out it had bent legs and one of the components missing (along with a bit of PCB).
I managed to find out that luckilly ripped side of the component was ground, so I did rebuild that missing pad. I think that those are capacitors meant to reduce noise, but unfortunately I don't know what value should it have?
I marked missing cap on a photo attached.
Anyone knows what cap can I safely put there?

p233.jpg

Edit: After straightening way too many pins I manged to put CPU in a socket and it posted. But still, I want to put this cap back.

Reply 1 of 6, by KungfuPancake

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You could take one of the others off and check the capacity - I suppose the voltage rating won't grossly exceed the CPU supply voltage, so I'd just take one with a package that fits and is at least at 6.3V or something like that.

Reply 2 of 6, by smoke86

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Yeah, I thought of that, but there are no guarantees that they're all the same. Plus I measured them incircuit and got different results for each one.
I'd do it as last resort, when everything else fails.
I'm also considering taking one cap from dead Athlon, it seems to be the same size.

Reply 3 of 6, by ChrisXF

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That's most likely going to be 100nf. Any voltage rating above 5v is going to work perfectly fine.

These are more than likely just simple decouplers, so if the cap from the Athlon is the same size go with that. 😀

Reply 4 of 6, by smoke86

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I soldered a cap from dead CPU (which turned out to be Duron) and it works, I'll install Win98 and then SuperPi to check if it is stable.

Reply 5 of 6, by smoke86

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After installing a system and running Duke 3D and Doom for half an hour I can confirm that the CPU is working stable.

Last edited by smoke86 on 2023-10-02, 07:39. Edited 1 time in total.

Reply 6 of 6, by pentiumspeed

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Excellent.

Cheers,

Great Northern aka Canada.