Watts Up: Fanny Thrice

Now that I have a system that initialises and passes power-on tests, I need to get an operating-system installed so I can test it under load. But first things first: to avoid the CPUs overheating, I need to get the fans installed and hooked-up.

The SPARCstation-10 fans were originally mounted on the outside of the old APS-39 PSU: this is by far the most convenient (or only) way to mount them properly anchored in the correct location, so I have preserved the now-empty APS-39 carcass to serve that purpose.

Although I mentioned previously that I had to destroy all the circuit-boards from the APS-39, that is not *quite* the case – I preserved the 12V fan-power distribution-strip from in-between the top and bottom halves of the APS-39 chassis:20150120_204952This is the only part just clipped in place, and thus is the only sub-board that can be preserved – fortunately, because this is the only board I need from the old PSU!20150120_222814and from the side, you can see where the fan-connector sockets poke out through cutouts:20150120_222623

There are three fans, and four 2-pole connectors to this distribution board – the 4th connector is the input (which is wired the opposite way around to the other three, but uses an identically-polarised plug, just to keep things confusingly simple!). The black twisted-pair cable is one from my junk-box, to replace the very short original red+white cable – I just needed to steal the connector off that red+white cable (by a stroke of luck, the internal crimped connectors on the black cable are exactly the same size, so they plug straight in to the other plastic shell without mods). Thats two crimps I have *not* had to do!

Next, there are a couple of repairs to make: after a lifetime of having the fans unplugged and replugged, tinker, tinker, the connectors on the board have come a bit loose, and the solder joints are breaking. First, superglue the plastic connector housings to the board then resolder the joints on the flip side.20150120_215407


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