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Bent pin on 68040 pulled from working Quadra 700


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So, I just decided to clean the board on my Quadra 700, and to prepare I lifted the processor. As it was coming up out of the socket I noticed that one pin looked to have been purposely bent over (see photo).

I’m curious as to why this was done, or if it’s a fault that somehow never caused any issues? 
if it does need bending back then I’d appreciate any tips on doing tha.

AC8302D7-183E-489F-8C83-2579E3C238C2.jpeg

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It shouldn't be bent, I'd say you just got lucky and the pin in question PST3 which "indicates the internal execution unit's status" conducted some signalling that perhaps wasn't so important.

 

If you have a retractable lead pencil (with the lead removed), this serves at the perfect pin straightener, otherwise very gentle plier work is OK

 

MC68040UM.pdf'

map-term-paper-motorola-68040-12-728.thumb.jpg.f3777f87e76684b8db2029389359dd57.jpg

Edited by Byrd
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That pin wasn't bent when the CPU was inserted. It couldn't be, else the CPU would've been at a noticeable angle.

 

If a pin is bent, and you keep pushing and make it flat, the pin will come out at or near a right angle to what it's supposed to be. If it comes out slightly bent like the photo, then your method for removing the CPU is likely what bent it.

 

You can put a credit card between the pins and gently push to straighten that pin.

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I've never worked on an '040 in particular, but I seriously bent numerous pins removing an AMD Phenom in another old computer I was working on. I was able to straighten all the pins acceptably by placing a credit card with its edge along the row gaps next to the bent pins and gently rocking it side to side to push the pin vertical. I would do this on both sides of the bent pins, and I would do it in the X-direction, then switch to the Y-direction, then back to X, until the pins were all straight. The result wasn't perfect, but after processing, the pins were all standing straight enough that the chip could be inserted back into the socket.

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On 5/10/2021 at 2:30 AM, Antibaddy said:

that’s how the pin was when I lifted the chip. It was bent over in a neat loop with the tip touching the base. There was a noticeable gap between the cpu and the socket.

 

Oh, I see. I was completely wrong. The "bent over" didn't register, and it looked as if the pin is just slightly bent towards the camera, but the lack of shadow shows that it's actually shorter, not just bent towards the camera.

 

The m68040 has lots of extra bus mechanisms that aren't used in most interfaces, so nothing else on the motherboard would care about the execution status, I bet. That'd be the kind of thing you might see used on a multiprocessor system.

 

Since it works with it bent, you can always try to straighten it using the tip of an X-Acto knife. If you break it, well, it was working without it, anyway :)

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