DECstation 2100: power trouble?
Mouse <[email protected]> Tue, 14 Apr 2026 22:40:59 -0400 (EDT)
| Newsgroups | gmane.os.netbsd.ports.mips.devel |
|---|---|
| Message-ID | <[email protected]> |
I've got a machine. The case calls it a DECstation 2100 and the bottom sticker says "CPU KN01". It does have (what is marked as) a MIPS CPU chip and the motherboard silkscreen has, among other things, the |d|i|g|i|t|a|l| logo and the text "KN01 54-19463-01", so I'm reasonably sure it is indeed a 2100. I tried turning it on. The lights stuck at EF. I pushed the reset switch and they changed tp 7F, then back to EF. I pushed the reset switch again and they flickered in a way that to my eye said "flaky connection to the LED common, or flaky power" (they flickered irregularly, all exactly in sync as near as my eye can tell). I opened it up and there is nothing obviously wrong to my eye. Nothing looks overheated to the point of damage and none of the caps in the power supply are visibly bulging, nor is there obvious mechanical damage apparent. Given the thing's age, though, flaky power seems more likely than something like a bad etch run giving an irregular connection to the LED common. Just because caps aren't bulging doesn't mean they're certain to be good, after all! But the power supply connector has something like eight different colours of wires across 14 pins. Does anyone know the pinout of that connector - that is, what voltages I should expect on what pins? Also, is the power supply capable of running with no load? (I've run into a few that aren't, including some that let out the magic smoke upon being powered up with no load.) I've got a fairly decent multimeter (a Fluke 87), so I can measure, but I'd like to know what I *should* get so that I can tell whether what I *do* get is good. If the voltages are compatible and the PS appears to be nonworking, I could hook it up to a boring peecee supply just to get the silly thing working; while I'd rather use the original supply, for my purposes I'd prefer a working FrankenPMIN to a dead original-equipment PMIN. /~\ The ASCII Mouse \ / Ribbon Campaign X Against HTML [email protected] / \ Email! 7D C8 61 52 5D E7 2D 39 4E F1 31 3E E8 B3 27 4B