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Project Alice

macrumors 68020
Original poster
Jul 13, 2008
2,018
2,087
Post Falls, ID
Alright, so in all my years of hoarding/fixing computers of all types I have NEVER in my life seen anything even close to this.
I’m aware of the notorious PSU problem on MDDs, I have one that doesn’t work because of that. I don’t think that the PSU is the problem this time, but that’s why I’m posting here. I can’t find anything like this on google either.

Here’s what happened. After I got this MDD all set up, HDDs and SATA card installed, I moved it over to my main desk that has a KVM switch. The MDD is replacing my Mystic G4 on the KVM. It’s a basic switch with USB, DVI, ect. The screen hooked up to that is a 23” ADC display. Anyways, I had just played with the MDD for like half an hour at a different desk with its own monitor and no switch. I moved it to the other desk with the KVM, turn it on and then it just shuts off! I turn it on about 10 more times, each time shutting off within about 5-10 seconds. I start troubleshooting, turning it on with everything unplugged but the power. I notice it stayed on, so I plugged everything back in. I saw my desktop for about half a second and it shut off again! Next time I turned it on with only the Ethernet and power cable, doing this allowed me to use it via screen sharing (it was already enabled due to the drive being in my Mystic prior to this). I was able to use the MDD as long as I wanted via screen sharing, so I plugged in the DVI cable. Not 3 seconds later it shut off!
To make it make even less sense, the other monitor that it was hooked up to at the other desk is also DVI.

TL;DR: MDD powers off when DVI cable is connected, and only shuts off when the DVI is connected.

I’m stumped. Could the card be drawing too much power at 1920x1200? (A sign the PSU is toast?) or is the GPU just bad and won’t display at that res?
 

z970

macrumors 68040
Jun 2, 2017
3,580
4,502
I'm not claiming any direct, intrinsic knowledge in this problem or general area, but my gut says that it's either a faulty PSU that can no longer fully supply the rated voltage due to age, surges, etc., or that there's some kind of switch going off every time it needs to output more power than it can take.

Either way, I'd start narrowing the problem down by connecting as many power-hungry peripherals you can attach to it and see if that has an effect. If it does and it can't handle it, this will more-so indicate a PSU problem. If all the peripherals are fine, and it's solely the DVI connector that shuts it down, I'd be more inclined to think there's some kind of weird power consumption issue on the card's side.

If you can, definitely try it with another card, and if you happen to have any DVI to VGA adapters around, it may be worth a shot trying to use that while hooked up to a VGA display, and then see if there's any differing effect.
 

Lastic

macrumors 6502a
Mar 19, 2016
879
756
North of the HellHole
Totally off-topic but out of interest what KVM are you using ? I'm still looking for a solution to hook up my MacPro and G5 to a 30" CinemaDisplay usinga KVM .
 

Project Alice

macrumors 68020
Original poster
Jul 13, 2008
2,018
2,087
Post Falls, ID
I'm not claiming any direct, intrinsic knowledge in this problem or general area, but my gut says that it's either a faulty PSU that can no longer fully supply the rated voltage due to age, surges, etc., or that there's some kind of switch going off every time it needs to output more power than it can take.

Either way, I'd start narrowing the problem down by connecting as many power-hungry peripherals you can attach to it and see if that has an effect. If it does and it can't handle it, this will more-so indicate a PSU problem. If all the peripherals are fine, and it's solely the DVI connector that shuts it down, I'd be more inclined to think there's some kind of weird power consumption issue on the card's side.

If you can, definitely try it with another card, and if you happen to have any DVI to VGA adapters around, it may be worth a shot trying to use that while hooked up to a VGA display, and then see if there's any differing effect.
That’s a good idea. I’ve already got 4 SATA HDDs in it so it shouldn’t be too hard to find more things to plug in l lol.
The only card I have is my Geforce 6200, which I couldn’t get to work in the MDD at all. I finally found themacelite’s cambatbility page shows MDDs as nor compatible with that which makes zero sense because it works in every AGO powermac ever including G5s. I also have some rage 128s and another Radeon 9000 from a FW 400 MDD I could try I guess.


Totally off-topic but out of interest what KVM are you using ? I'm still looking for a solution to hook up my MacPro and G5 to a 30" CinemaDisplay usinga KVM .
This is my KVM switch, but it won’t work on your 30”. It tops out at 1920x1200 which happens to be the resolution for a 23” apple display. I’d imagine that they make higher resolution ones though.
 

Amethyst1

macrumors G3
Oct 28, 2015
9,315
11,422
I haven't tried that yet, I probably should. I'll try that next. I was getting annoyed last night and I had to go to bed to get up early for work.
If things work fine without the KVM, I'd move on to trying all the KVM's DVI inputs. Maybe it's some kind of a short-circuit. Also, what GPU is in the MDD right now?
 

Project Alice

macrumors 68020
Original poster
Jul 13, 2008
2,018
2,087
Post Falls, ID
If things work fine without the KVM, I'd move on to trying all the KVM's DVI inputs. Maybe it's some kind of a short-circuit. Also, what GPU is in the MDD right now?
I had that exact cable hooked up to my Mystic prior so I doubt it, but anythings possible.
The stock Radeon 9000 Pro is still in it.
 

Project Alice

macrumors 68020
Original poster
Jul 13, 2008
2,018
2,087
Post Falls, ID
Update: This is too weird. I don’t think it’s the PSU. At least I’m not confident enough to spend the money for a refurbed one.

So, I plugged back into the smaller DVI monitor, then ran some benches. Geekbench and xbench. It stayed running.
After that, I plugged it into the aforementioned ADC monitor; directly without the KVM. So the monitor was being powered by the PowerMac through ADC and not the adapter. It worked! I played with it for a few minutes, no shut down. Also I have a pair of cube speakers that are connected to the back of the display; meaning they were also powered by the PowerMac’s ADC port.

I then plugged back into the switch, not even in the same spot. I moved my Mac Pro out of the way and used it’s spot on the switch. As soon as I powered on the PowerMac, it shut off a few seconds later as described. What in the f***?

The only other things I can think to test out are using another DVI cable to the switch (instead of the cables that came with it) and a different video card.
 

z970

macrumors 68040
Jun 2, 2017
3,580
4,502
These Power Mac G4s are problematic. Just scrap the damn thing and stuff an SBC inside. :D

Life's too short to stress over.
 

DeltaMac

macrumors G5
Jul 30, 2003
13,425
4,392
Delaware
The ADC display gets its power through the video card.
If the display works hooked directly from the MDD, and won't work through the KVM, then must be a problem with the KVM.
Maybe the video card on the MDD has just enough to power the display directly, but adding the KVM is too much drain on the power supply.
(Your older Gigabit G4 may have had more available power, or the graphics card and its connector might have been in better condition, allowing the KVM to work without problem)
Something to try - if you haven't done this: Reseat the graphics card in the MDD, multiple times. You could also use the eraser trick to clean the contacts specifically for the ADC connection (That's the small edge connector, near the connector end of the video card.)
 
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Project Alice

macrumors 68020
Original poster
Jul 13, 2008
2,018
2,087
Post Falls, ID
The ADC display gets its power through the video card.
If the display works hooked directly from the MDD, and won't work through the KVM, then must be a problem with the KVM.
Maybe the video card on the MDD has just enough to power the display directly, but adding the KVM is too much drain on the power supply.
(Your older Gigabit G4 may have had more available power, or the graphics card and its connector might have been in better condition, allowing the KVM to work without problem)
Something to try - if you haven't done this: Reseat the graphics card in the MDD, multiple times. You could also use the eraser trick to clean the contacts specifically for the ADC connection (That's the small edge connector, near the connector end of the video card.)
I've already done that. I actually already removed the graphics card from the MDD a few times when I was trying to get the geforce 6200 to work (then I found out they don't work in MDD's for unknown reasons).
I also tried another cable and that didn't work either.
The ADC connection isn't the problem, the KVM is DVI. I've had more G4s other than the gigabit connected to it too. Sawtooth's, quicksilvers, and G5's have all worked on it. The KVM shouldn't be drawing any more power than a standard DVI connection is... And even if it was I highly doubt it would draw any more power than the direct ADC connection from that 23" display.

I'll have to try another video card.. My only option is another Radeon 9000 from a different (non working) MDD. All the other AGP cards I have are either AGP Pro for G5's, or they have ADC + VGA which won't work as I need a DVI port (I don't own an ADC to DVI port adapter). I guess I could slap a Rage 128 in there, but that won't even drive the monitor at 1920x1200.
 

Amethyst1

macrumors G3
Oct 28, 2015
9,315
11,422
The ADC connection isn't the problem, the KVM is DVI. I've had more G4s other than the gigabit connected to it too. Sawtooth's, quicksilvers, and G5's have all worked on it. The KVM shouldn't be drawing any more power than a standard DVI connection is... And even if it was I highly doubt it would draw any more power than the direct ADC connection from that 23" display.

Can you try hooking up the display to the MDD via DVI, i.e. hooking up the A1006 adapter to the MDD, again bypassing the KVM? Does that work? On a different matter, I presume the A1006's USB cable is connected to the KVM. Do these problems also arise if the USB is not connected?

Also, while this may sound silly, I reckon it's worth trying hooking up the MDD to the KVM after disconnecting the display/A1006 adapter (including the USB cable) from the KVM to see if the problem boils down to the KVM alone or the particular combination of the KVM and display/adapter.

Whatever, it's a puzzling situation for sure.
 
Last edited:

Project Alice

macrumors 68020
Original poster
Jul 13, 2008
2,018
2,087
Post Falls, ID
I think I might have narrowed it down to the Radeon 9000 Pro in general. Still not 100% until I get a card that works in the MDD (I've got a Radeon X800 coming from eBay).
I swapped in the other Radeon 9000 Pro, and it did the same thing. So I installed the only other card I could think of with a DVI port; a Rage 128 Pro. That didn't work with the 23" display which I knew, but it was trying and the computer never shut off.
I wish I could stick one of the 3 Geforce FX 5200s I have, but since apple decided that it was necessary to make those AGP Pro for the G5s that's a no-go. I always thought that was dumb. 5200s aren't fast enough to saturate the AGP 8x bus and definitely not AGP Pro.

Anyways,
I just put a Radeon 9000 Pro in my Mystic that usually runs with the Geforce 6200, and hooked it up to the switch. Now it doesn't shut off as early as the MDD does, but it does eventually shut off. In the MDD, the computer stays on barely long enough for the monitor to register a signal and turn on. The Mystic, boots up all the way until the GUI is loaded (the blue screen) and then shuts off. I was able to replicate that three times in the Mystic.
 

Project Alice

macrumors 68020
Original poster
Jul 13, 2008
2,018
2,087
Post Falls, ID
So it looks like there is some weird incompatibility with ADC video cards, and KVM switches. I hooked up my G5 to the switch in the G4's place, and it did the same thing! I guess the last time I had a G5 in that spot was before I had the switch.

I just stumbled across this thread. It is exactly what is happening to me. And it isn't even the same switch. Not even the same brand! My G5 has a Geforce 6800 Ultra in it, which doesn't even have an ADC port, but is powered by ADC. I guess the reason my sawtooth and mystic worked was because they had a Geforce 6200, which is of course a PC card, and doesn't use ADC.
So, it looks like I'm pretty much SOL. Unfortunately I don't have enough (any, actually) space to have computers on their own monitor.

Luckily I've got an X800 coming from eBay, so that should make it to where the MDD can sit on the switch as it won't have ADC, and the G5 can go back to its own desk (where I stuck the MDD for the time being).

I'm not going to mark this as solved, because techincally this is a problem. But at least there will be some kind of documentation if anyone else runs into this problem.
 
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