G4 AGP motherboard in B&W G3 case

apart from the ports (and maybe the mobo mountings) it should be pretty similar as they use the same case design

TOM

I was thinking about doing the same thing. From the reading I've been doing, the B/W g3's shipped with only a 130 watt (or something like that) power supply and that the upgrade manufacturers kept frying power supplies trying to upgrade the processor. The g4's all seem to have at least 200 watts, dependent upon the mobo/processor combo. Could a g4 power supply just be swapped in? I'm game for trying this out.

id be willing to bet a earlier G4 (original -> "digital audio") would fit fine ... as they use the same case as the G3 ... the Q.S and MDDs have different internal layouts ... so i would think the PSU would a different shape ...

one thing that you should also note is that the "digital audio", Q.S and MDD G4s have 4 PCI slots and a AGP slot, while the earlier ones only have 3 PCI slots and a AGP slot (or a 4th PCI slot) ... so you may need to adapt the case abit ...

TOM

My Blue & White shipped just before the G4's came out, with a 200W PSU. So it is safe to assume some Rev 2 B&W systems have stronger PSU's

Secondly, the B&W/Yikes/Sawtooth PSU is very close to that of a standard ATX PSU. There is one wire that needs to be cut for it to work (if you do not cut it, you will fry your board). With this knowledge in hand, you can go to your local computer parts shop or CompUSA and grab a replacement, or even stronger PSU, hack the wire off, and install.

http://www.xlr8yourmac.com/systems/MacinPC_ATX_case/Blue_G3_to_ATX.html
(Read section about ATX Power)

As noted in my just posted thread:
http://www.applefritter.com/node/view/2464

I just picked up a bunch of B+Ws, a complete Sawtooth as well as a bare QS LB. I stuck the QS LB into a B+W shell, it looks to be too much work to bother with. The biggest problem is the 5 PCI/AGP slots, which means a significant amount of sheet metal work at the back. Since a nice QS case can be had for ~$100 or so, hardly seems worth the bother.

I think any of the 4 slot LBs ought to work without too much trouble though. I'll compare my Sawtooth with the B+Ws and report backwith details.

Dan K

Well, not only are the PCI/AGP slots a problem with the Quciksilver-in-BW setup, but also the PSU is incompatable (needs 28v rail, so rewiring of an ATX PSU or purchasing of a Quicksilver PSU is necessary) and the metal plate used to mount the motherboard is different (Gigabit G4 and later have a spot that is raised up to contact a chip on the back of the board, acting as a heat sink)

If you can grab a Quicksilver case, great. If not, there is always the option of putting it in an ATX case.

Hi Captain,

Can you recommend a odel and brand ATX powersupply that I can modify to work in my G4 Quicksilver ?

Thanks, Jose

If I understand the qouted passage: Standard ATX cases with the standard ATX PSUs can be modified [by snipping a wire] to accept Apple MBs.

The G4s originally installed in a Mac tower case [Which originally Mac Tower cased G-4s ... any and all, or only certain originally Mac tower case MBs?] can then be easily installed in the ATX case with modified PSU. Then a "new" Mac can be [re]born into that ATX case with little difficulty.

Is that a correct understanding??
I have a couple ATX cases laying around. So, if that is an accurate understanding on my part, I may try to recycle the ATX case as opportunities may present themselves (or not.)

David Johansson

I've just done this very thing. Today, in fact.

The back panel I replaced with some plastic, cut to shape. Beyond the audio ports, the Firewire ports are in a different location as well.

I used a standard ATX PSU, since the G3 I had didn't come with a power supply. I snipped the power supply wires based on the article here.

PCI/AGP line up fine.

I cut a PC floppy cable up and wired a cable from the g4 10-pin front panel interface to the G3's 20-pin interface. Use the link above, plus search XLR8 Your Mac for B&W G3 to ATX for pinouts for both interfaces.

The main modification to the case is there's a logic board mount on the B&W G3 that doesn't exist on the Sawtooth. It's near the G4 CPU area. I twisted the mount off. Rather brute force, and it might have done okay to stick a bit of black tape overtop, but suit yourself.

The secondary IDE is in a different position, but that's not too much of a deal to shift.

I still need to mount a fan at the side of the heatsink, as the G3 doesn't have that big 120mm fan and vent bracket inside that the G4 case has.

edit: I'd forgotten another change I had to make...
A previously installed ATX PSU when the case still contained a G3 required filing the blue plastic around AC outlet. The ATX PSU had slightly larger plastic fairings around the outlets that prevented it from sitting flush against the G3 case.