PRAM won't zap?

[trag]

It's rev. B or Rev. C.     Which is good.   But with only one device on each cable, it shouldn't matter any way.

So, if you plug in either the CDROM drive or the IDE hard drive into either of the IDE ports, the machine does not boot?

If that's the case, one last long shot, try a different memory stick.   Why?   It's possible that you have a faulty memory location and that the IDE's driver is always occupying the same location in memory, and that the two happen to correspond.   Like I wrote, it is a long shot.

I'm just having trouble accepting that both IDE ports would be bad.    I don't think I've ever seen that in a Beige before.

 

[Iamanamma]

I'm just having trouble accepting that both IDE ports would be bad.

Right now I have the original hard drive running off one of the IDE ports.  I haven't tried switching yet.  I am suspicious that the PSU might be a problem as well.  This is why: I noticed the zip drive wasn't functioning, it's SCSI.  The power cables with p2 (to the HD) and p3 (to the CD-rom) also had a 4 pin power connector on it. I think it's called a floppy style connector.  There was a lovely little open power port that size on the back of the zip drive.  I turned everything off, unplugged the power, plugged the connector into the zip drive, plugged the power cable back in, and powered up the G3.  No love from the zip drive.  So, I powered back down, unplugged the connector, and grabbed the cable with the P5 and p6 connectors on it.  I stuck a spare 4 pin Molex to floppy style connector onto one of them, and reconnected the zip drive to that.  It's all by itself, the only other SCSI device on the bus is a SCSI2SD card, but it gets enough power to run itself from the SCSI cable.  Powered up again, and now there is love from the zip drive.  Now I admit I don't know anything about how the PSU divvies up power between its various cables, but I though it odd that the zip drive would not function unless it was on another cable.

 

[trag]

The Beige G3 can run off of a standard ATX power supply.    There's a jumper on the motherboard to switch it between expecting the Apple PS in the desktop case, or an ATX style supply, which, IIRC, is in the tower case.   Look up the detials somewhere reliable before trying it.   My memory is vague except that the jumper exists.

 

[Iamanamma]

or an ATX style supply, which, IIRC, is in the tower case.

What I am favoring restoring are our G3 towers.  If I am understanding you correctly, the beige G3 towers have the ATX power supply?  I would be able to find the same thing without excessive amount of difficulty?

 

[trag]

What I am favoring restoring are our G3 towers.  If I am understanding you correctly, the beige G3 towers have the ATX power supply?  I would be able to find the same thing without excessive amount of difficulty?

That's what I remember.   You should double check though, because my memory is hazy.

 

[Brett B.]

I just read through a couple articles on the xlr8yourmac site (via archive.org....) that seem to confirm that the beige G3 tower does in fact use an ATX power supply and the motherboard jumper is set to PS/2 power supply... the desktop G3s are set to Mac and have a different PSU.

I'd just verify that the ATX PSU of your choice has the correct connectors you're using now - some new ones don't have the older Molex/floppy connectors anymore - and if it does you should be good to go.

I saw mention of the voltage regulator - I think the one pictured looks fine, the discoloration appears to be maybe solder flux and not so much leakage.  There was also an issue with these years ago involving Royal brand VRMs that failed and were replaced... yours is a Raytheon so it should be fine, just keep that in mind if you run across one marked Royal.

 

[jessenator]

20-pin vs 24-pin. Some PSUs have the extra 4-pin "break off" from the main connector.

As wasteful as it sounds, I was looking at (cheap) modular PSUs as a replacement for several of my machines, actually. I'm not a fan of the molex-everywhere approach, which was basically the only approach in the 90s.