Resolved Power Mac G4 install issues...

[captainfamicom]

My Power Mac G4 isn't doing so well. It worked fine till the PRAM battery died, so I replaced it, reset the PRAM, PMU, etc. It would not boot off Mac OS X Tiger, or even Mac OS 9, so I wiped the disk. When booting from my OS 9 CD, it freezes about 3/8ths the way through the bar, and my Panther CD just shows the Apple logo. I have tried to reseat everything, even swapping ram sticks for some of my spares. Any thoughts?

 

[eyoungren]

Take the PRAM battery out.

Pull the power cord out of the PSU in back. Press the power button as if you are going to start the Mac. Do it a few times until there is no life in the Mac. That'll discharge all the the power in the system.

Put the PRAM battery back in, plus the PSU back in and see what happens.

Just guessing here, have absolutely no idea if this is just a dumbass idea or not.

 

[z970]

Pull the power cord out of the PSU in back. Press the power button as if you are going to start the Mac. Do it a few times until there is no life in the Mac. That'll discharge all the the power in the system.

Does it really??

I thought you had to unplug it and wait a week or two to discharge the PSU.

 

[captainfamicom]

Nope, although it did give me green bars for half of the screen when it tried to boot off my OS 9 CD.

The computer if you are wondering has Dual 450mhz and 1.25 GB of ram. Great file server when it worked.

 

[Raging Dufus]

It worked fine till the PRAM battery died, so I replaced it, reset the PRAM, PMU, etc.

By "reset the PRAM, PMU, etc." - what exactly do you mean? I'm just wondering, because Power Mac G4's have an actual button to press for that (on the logic board), unlike a lot of other PowerPC-based Macs which utilize keyboard/power button input combinations.

I've run into problems myself in the past when I've replaced a PRAM battery or other parts of the power system on a Power Mac G4, if I didn't press the reset button after I was done. I would follow all of @eyoungren's advice, but in addition I'd also make sure to press that reset button before you try booting it again.

 

[captainfamicom]

I followed all of it, and I have pressed the button for the PMU. I reset the Pram on boot up, yet it still won't work. I have done this before on another system for a friend, and his worked fine. I don't know why it isn't doing much on mine.

 

[z970]

Try following this gentleman's actions exactly.

 

[Raging Dufus]

OK, let's go over what you've done so far:

• You've wiped the hard drive, so that should eliminate any issues with corruption of the OS, software, or extensions problems. You're starting fresh.

• The fact that you've tried two different install CD's for two different OS's, with similar results, seems to indicate that the installation media you're using is not the problem.

• You've swapped out RAM, which likely eliminates that as the culprit.

• You've replaced the PRAM battery, pressed the reset button, and followed the other suggestions to eliminate stray power issues.

• The Mac will not complete a boot from CD/DVD (just like it wouldn't boot from the OS's that were installed on the hard drive): this tends to indicate that neither your hard drive nor your optical drive are the problem.

Yet, you're still having the following issues:

• You're seeing artifacting (green bars) on the display during boot. This could mean that the graphics card has a problem; and depending on the severity of the problem (if there is one), that could definitely interfere with booting.

• I'm also suspicious of a power issue here, since your problems seemed to begin concurrent with your replacement of the PRAM battery. One of the first victims of a failing power supply unit tends to be the graphics card in many cases; and could also explain why you needed to replace the PRAM battery (or was that just precautionary on your part?). It's possible that you need to replace your PSU. It's also possible that you just got a bad PRAM battery, even though new. It happens.

• It's also possible that you have a failing logic board and/or CPU daughter card; in which case you will have to replace one or both.

I think the cheapest/easiest thing to test, under these circumstances, would be the graphics card. Do you have another Mac in which you could test it, or, do you have another graphics card that will work in this Mac?

 

[z970]

I second removing the graphics card.

Several days ago, my Mac Pro wouldn't boot into Debian, El Capitan, or the Snow Leopard disc. The first two would keep rebooting before finishing boot, and the third would KP.

I tried a lot of things + trail and error to get it going again (to no avail + it's my work computer and I can't afford for it to be dead), but out of nowhere, I got a hunch that it was the GPU. So because I had two installed, I removed the GeForce 8800 GT, which has given me problems in the past because it can be susceptible to heat issues (similar to the 2006 - 2008 FlakeBook Pros), leaving its additional GT 120 inside. Afterwards, it sprang into action, perhaps a little bit faster than before, as if nothing ever happened.

Try removing your video card, wait a while for the computer to possibly boot up, enter your password with the greatest of hopes, and attempt to adjust your volume while hopefully at that point being booted into your desktop. If it was the GPU, it should have booted, logged in just fine, and displayed the sound feedback from your speakers when adjusting volume. This way, you can deduce that you've arrived at your desktop without issue, and can then mark the GPU as bad.

I might repaste/pad my 8800 GT just to make sure there's nothing I can do to revive it (circuit board looks fine), but if that doesn't work, then I've got a spare fan and cool-looking enclosure to play with afterwards.

 

[captainfamicom]

I used a tester on the old battery and it was flat, the new one was good. I do not have a spare GPU or machine to test it in, as my only other PPC machine is a TiBook. I feel as if it is the Power supply though, but at the same time, I recently took out the logic board to use compressed air to clean it, and it worked for a day after that, in which the battery died. I was already thinking about getting a new GPU for the machine, but if I can get mine to work, I will just hold out. My closest desktop Mac is a 2006 Mac Pro.

 

[z970]

I used a tester on the old battery and it was flat, the new one was good. I do not have a spare GPU or machine to test it in, as my only other PPC machine is a TiBook. I feel as if it is the Power supply though, but at the same time, I recently took out the logic board to use compressed air to clean it, and it worked for a day after that, in which the battery died. I was already thinking about getting a new GPU for the machine, but if I can get mine to work, I will just hold out. My closest desktop Mac is a 2006 Mac Pro.

Try my idea. Boot it headless, type your password after waiting a while, and adjust the volume. If you hear sound from your speakers, it means the computer has safely gotten into the desktop, which points to the GPU being the issue.
[doublepost=1536721531][/doublepost]My humor is criminally underappreciated.

You people don't deserve me.

 

[captainfamicom]

No sound, but at the same time, I flashed the hard disk with an image from a good install to test, and with the video card, it boots the same amount. Is the power supply standard? I have one not being used that has the same connectors, so I am wondering if I could test with it.

 

[Raging Dufus]

Is the power supply standard? I have one not being used that has the same connectors, so I am wondering if I could test with it.

Nope, not standard. Power Macs use modified ATX power systems, and the PSU's on the GigE/Mystic (based on your specs, I'm assuming that's what you have) are modified even further to accommodate ADC displays. So unless the spare PSU you have is also from a Power Mac G4 Gigabit Ethernet model, it won't be plug & play.

But, the good news is, you can make a standard ATX PSU compatible with your Power Mac. See my discussion here (different model of Power Mac, but same principles) and check out the info here. If you're actually using one of Apple's ADC Cinema Displays with your Mac, it gets a bit tricky, but it can still be done.

If you're not using an ADC display, and just need to power up your Mac, that's no problem at all as long as you're comfortable splicing wires and/or swapping pins around in a power connector. Just be careful to follow the instructions precisely, or bad things could happen.

 

[z970]

No sound, but at the same time, I flashed the hard disk with an image from a good install to test, and with the video card, it boots the same amount. Is the power supply standard? I have one not being used that has the same connectors, so I am wondering if I could test with it.

Well, I got nothing.

 

[Raging Dufus]

If you've eliminated the graphics card as the problem, at this point it could only be one of three things:

1. The PSU
2. The CPU
3. The logic board

Or, it could be two of those, or even all three. Swapping them out for known good replacements, until you find the problem, is your best bet.

 

[captainfamicom]

Welp, It was the power supply. I ordered a new one, so its all good.

 

[z970]

How'd you find out?

This could help us with diagnosing future issues from future inquiries. Often I'm scratching my head with what component exactly could have failed.