atx psu in my g4

[mayhew2345]

will a pc power supply work in my sawtooth g4 its a 20pin motherboard connection i see many pc powersupplies with 20 and the 24 pin interfaceonly reason i need to upgrade my ps is a new nvidia 128 video card im going to run.. the stock 217 max ps may not work (gonna be iffy)

[Cryptic Clues]

In my opinion, with a “SawTooth” fitting a replacement ATX PSU is not a problem, the motherboard and the PSU are both 20 pin "Molex" connections, all you have to do is change pin 8 to +3.3v and pin 18 to ground. There are several guides to doing this on xlr8yourmac but they entail cutting and soldering.

 

I think my method for a placing an ATX PSU into a SawTooth is easier, in that you do not have to cut any of the supply wires from the PSU or be adept at soldering, the only cables you will be modifying will be those on an ATX 20 pin extender cable which you will need anyway because 99% of the time the ATX supply cable will be too short to reach the motherboard, plus it's cheaper to get another extender cable should a mistake be made than what it is a new PSU.

 

So what is required:

 

1 off 20cm ATX 20 pin extender cable (roughly £1.50 on eBay)

Make, beg, steal or borrow 2 off 18swg “Y” cables preferably orange and black but any colour will do.

Now remove the following cables from the ATX extender:

 

2 Orange

8 Gray

17 Black

18 White

Now replace them with a “Y” cable from:

 

Pin 2 to Pins 2 and 8 on the motherboard connection.

Pin 17 to Pins 17 and 18 on the motherboard connection.

You should end up as per the pin-out on the link below.

http://www.outofspec.com/frankenmac/wire.shtml

 

If you wish to do the soldering method look at following link

http://www.xlr8yourmac.com/systems/ATX_G4_...TX_case_pg2.htm