On Jun 26, 2009, at 10:05 AM, geno.y wrote:
>> I'm sure you're finding out that it is nearly impossible to repair or >> replace a Mac PSU economically. If you change you mind about using a >> pc power supply you'll find it's not that difficult, I can email >> directions and wiring diagrams if you like. > > I don’t know about Paul, but I would like a copy of the directions. > I’ve got a few G4 Gigabits and I know the PS will go sooner or later. A G3 and G4 Mac PSU is identical in size and mounting screw positions to a full ATX PSU with the following changes: 1) where a full ATX PSU has #6-32 UNC fasteners, all Mac PSUs have M3-0.6 fasteners, and 2) the connectors are, for the most part, quite different. (I'm sure there are other differences, as will be identified by others, whom I encourage to do so). Now, the interior of most PSUs is fundamentally identical. I will only comment on the output side, as the input side is unique to each PSU, although a common component is the IEC connector for power. In the output section are quite a number of pads where the exterior conductors are terminated. Usually there are about a dozen ground pads (not all of these are used), and a lesser number of +3.3 volt, +5 volt, +12 volt, -12 volt and -5 volt pads. One strategy which could work would be to disassemble the failed Mac PSU and remove each external wire where it is soldered to an internal pad, then solder that wire to the equivalent pad within the generic full ATX PSU (after removing the ATX PSU's external wires, of course). The job is made easier if you don't mind slightly shorter wires (but about 1/4" shorter). Simply cut each wire with diagonal pliers and then strip the insulation back by the requisite amount. Generally, a Teledyne "hot wire" stripper works best. Oh, and the wire diameter of #6 is almost identical to the wire diameter of M3 (yes, machine screws are drawn from very large coils of steel wire, and the threads are "rolled", not cut), so it is possibly to carefully pass an M3.5-0.6 tap through the #6-32 UNC threaded holes in the generic ATX PSU, thereby converting it to all- metric, which is what the Mac expects. --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed Low End Mac's G3-5 List, a group for those using G3, G4, and G5 desktop Macs - with a particular focus on Power Macs. The list FAQ is at http://lowendmac.com/lists/g-list.shtml and our netiquette guide is at http://www.lowendmac.com/lists/netiquette.shtml To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/g3-5-list?hl=en Low End Mac RSS feed at feed://lowendmac.com/feed.xml -~----------~----~----~----~------~----~------~--~---
