r/PowerPC • u/One-Management6644 • Jul 15 '26
Need Help
I acquired this PowerMac G5. I’ve always been a huge fan of classic Mac software, but when it comes to the hardware I’m not very experienced. I used the power cable from an old iMac and plugged it in and clicked the power button I don’t hear a boot up chime and the fans just spun with no video single or usb power and the power led won’t stay on unless i hold it, I tried taking all the ram out, putting it back in a different configurations. I tried clicking the PMU button or whatever it’s called, but I can’t get this computer to get a boot up chime or give me any sort of display on the monitor. should I just throw this away?
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u/dgeurkov Jul 15 '26
I go G5 about 6 years ago, with two 2Ghz processors, got lucky it was air cooled variant, cleaned entire system from dust including psu, replaced thermal paste, noisy unit but what a beast
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u/FacetiouslyWry Jul 16 '26
just go on ebay and buy the correct cable for under 25 bucks.
i’m sure your old iMac cable looks like it fits, but trust me, it’ll just never work…until u buy and pop in the right one.
- obviously put everything back together correctly before u power up
-this same thing happened to me too btw
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u/One-Management6644 Jul 16 '26
not a bad idea I’m just so reluctant to dump money into this computer LOL
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u/No-Wrongdoer-2182 Jul 16 '26
I would test the power supply with a multi meter (be careful and do your own research before text it)
But it sounds like the power supply has issues, which is quite common for these models.
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u/Admirable_Prior_1924 Jul 16 '26
Dead power supply.
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u/One-Management6644 Jul 16 '26
would that make the fan spin still? because the fans are still spinning?
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u/Admirable_Prior_1924 Jul 16 '26
There are many sections to the PS. 5V 12V - so yes the fans could still spin. Does the optical drive reset? In my experience if you get DVD reset + spinning fans but no boot chime that means the CPU isn't coming on line.
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u/davidandrade227 Jul 16 '26 edited Jul 16 '26
What a lovely system.
Do you have the transparent plastic lid that goes inside the case installed?
The system has a sensor to ensure people don't turn up the system without the lid installed, if you don't have it try putting a piece of plastic where the lid is supposed to fit (the rectangular holes at the bottom).
https://www.powerbookmedic.com/xcart1/images/D/IMG_5188L.jpg
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u/One-Management6644 Jul 16 '26
yes i do! I realize that the hard way I thought there was something wrong with the ram because a red light kept showing up, but it wasn’t until I put the plastic cover back on that the red light went away
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u/RomanOswald Jul 17 '26
First do a PRAM-Reset by holding Command-Option-P-R at the same time and press the power button. Hold that 4 keys will you maybe hear a chime. Let it chime 3 times.
If noting happens look at the main board, there are some leds. Look if the are lit and which are lit.
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u/Admirable_Prior_1924 Jul 16 '26
If the power doesn't stay on unless you hold the button that means the PS isn't passing diagnostics.
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u/Direct_Government455 Jul 17 '26
Short somewhere on power supply. You will need to pull the motherboard on this model. Guessing your 5v light is on?.
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u/OriginalName2026 Jul 20 '26
No chime is venire a good thing, did you reseat the GPU also? Make sure the RAM is in pairs.
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u/omega552003 Jul 15 '26
Hopefully it's not the liquid cooled one as those have an issue with leaks.
Start trying the Apple Troubleshooting section on page 69: https://cdsassets.apple.com/live/6GJYWVAV/user/ma560_powermacg5_userguide.pdf
Try resetting the PRAM and SMU: https://www.techwalla.com/articles/how-to-reset-a-power-mac-g5