Macintosh question (G3, 7 years old, so OT)

[Doc Shipley]

Ethan Dicks wrote:
> A quick question about the Mac G3, if you'll forgive it being not yet
> on-topic.  Feel free to reply off-list to avoid rampant topic drift...
> 
> Does anyone here know about the internals of the G3 line?  I have a
> motherboard in front of me that I'm attempting to see if it will work.
> It came from a machine that had already been stripped, so there's no
> guarantee the hardware is functional.  With the Apple Reset/NMI board
> installed, and RAM, and the Apple-enhanced ATI Rage 128 video card,
> I've attempted to see if it works by plugging in a PC ATX power supply
> and pressing the "power on" button on the motherboard and on the
> Reset/NMI board.  I get a brief green flash from several LEDs, but the
> PSU doesn't kick on the fan, and the machine does not appear to be
> starting.
> 
> Do I need an Apple ATX supply to test this?  Could this be a battery
> problem? (the battery was completely dead and I have no handy
> replacement, so the battery compartment is empty)
> Do I need to have a keyboard and mouse plugged in to get a response?

   Ethan,

   There are a couple of different G3 system boards with very different 
PSU inputs.  As far as I know, neither is PC ATX compatible.

   www.xlr8yourmac.com has some pages that detail converting an 
off-the-shelf ATX PSU for use on a "beige" G3.  IIRC, that one requires 
a simple inverter board.

   The Blue & White G3 I haven't seen plans for, but I'd bet its PSU is 
closer to PC-ish.


	Doc