Ram slot failure in late 2012 A1347

Thank you—yours was a decent suggestion, but (using a mirror + magnifying glass) I detected no abnormalities in the pins. With nothing to lose, I gave the slot light passes with very fine emery paper but three beeps sustains.

The only explanation I have as a possible cause for this apart from "stuff happens" and "decay is inherent in all conditioned things" is that my installing an SSD as a system drive and swapping bays for the original data drive but not reformatting both drives as a fusion drive may have led to inconsistencies in the logic system—the mini did have an irritating habit of sleeping and then shutting down unbidden if left unattended for any time despite being set up to never go to sleep unless commanded to.

Thanks again anyway.

Possibly so—it took 13 months during which time both drives were working for the damage to show up, however.

Perhaps ants ate away at some succulent insulation on the board—there's a very small local species that tends to like electronics; given half a chance they'll nest in a hard drive. That or possibly a heat related issue—I live in the tropics and do not use air-conditioning—may have caused the failure.

After the failure I removed the sata drive—there was no indication of ant activity.

Upon reflection, a component failure on the logic board seems likely since just before the triple beep manifested, I had to reboot twice after random segments on the screen began to look unstable followed by a system freeze a few seconds later about 10 minutes after start up.

This was written on said mini, which is working fine on one 8mb chip so far...