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I hope this question lies within the guidelines.

I have acquired this AMD 5600x microprocessor for a very low price. It was dropped on the corner (see picture) where we can see some delamination.

The seller just says it does not work anymore but I have not tested it myself yet. I will try a memory stick and the normal debug before the questions/solutions below are considered.

enter image description here

None of the pins are bent. I think the subtrate PCB is 12 layers with all vias buried. The damage does not go "underneath" any of the pins.

A couple of questions:

  • Would the layout engineer be forced to route this close to the edge? Beyond where the pins are?
  • Can I use a multimeter to test for short circuit on a device that could take 200 A at ~1.4 V maximum? Would the multimeter test with too high voltage?
  • Should I try and tape the corner back together? (If the copper/via is ripped this would be a shaky solution.)
  • Should I Dremel it pretty and perhaps remove a short circuit between the layers?
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    \$\begingroup\$ ”Would the layout engineer be forced to route this close to the edge? Beyond where the pins are?” Unlikely with that many layers. \$\endgroup\$
    – winny
    Commented Jan 4, 2022 at 9:30
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    \$\begingroup\$ Testing for shorts would be useless imho. There's many parallel (power/ground) pins on such a CPU which would all measure short and the problem might be a break rather then a short. \$\endgroup\$
    – Unimportant
    Commented Jan 4, 2022 at 9:37
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    \$\begingroup\$ ”Would the multimeter test with too high voltage?” Most multimeters are designed to test with less than one diode drop of forward voltage unless you put it in diode mode. Modern super low voltage ASICs could potentially still be triggered open, but I doubt you would damage something inside it. I would worry more about ESD damage. \$\endgroup\$
    – winny
    Commented Jan 4, 2022 at 9:39
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    \$\begingroup\$ Main issue probably won't be routed traces but ground planes etc getting shorted against each other. And if someone has powered it up with a short present, anything could be fried. \$\endgroup\$
    – Lundin
    Commented Jan 4, 2022 at 9:42
  • \$\begingroup\$ @Lundin So it would be best to try and clean up with a dremel? \$\endgroup\$
    – EmilBonnevie
    Commented Jan 4, 2022 at 9:54

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Here's a snapshot from a disassembled 5600x:

enter image description here

Image Source

If you look closely at the corners, you'll see that there are copper-poured areas (There are some tiny holes which look like vias but I'm not sure if they really are).

So,

Would the layout engineer be forced to route this close to the edge? Beyond where the pins are?

Most likely. Even if there are not tracks there, there could be some buried vias. So we can assume that there are tracks close to corners, even if the top plane is presumably a power or GND plane.

Should I try and tape the corner back together (if the copper/via is ripped this would be a shaky solution)

The tracks or vias are most likely damaged so this does not seem to be a solution.

Or should I Dremel it pretty and perhaps remove a circuit between the layers?

And this does not, as well.

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  • \$\begingroup\$ So you would simply give up if it does not work out of the gate? \$\endgroup\$
    – EmilBonnevie
    Commented Jan 4, 2022 at 12:32
  • \$\begingroup\$ Around the first 486 CPUs it became clear that repairing something more than a bent pin is causa perduta. \$\endgroup\$
    – fraxinus
    Commented Jan 4, 2022 at 13:55

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