iMac G5 boots with fans on full/blue screen

[MattA]

Hello All! My wife has had a 17" iMac G5 (Radeon 9600 version) for the past 11 years or so. It's no longer her main computer, but she still uses it for music and various small tasks.

The other day, when she woke it from sleep, it woke up with the fans on full blast. It also just shows a blue screen. Powering off and on makes it come back to life for a bit, then it goes back to blue screen with fans on full.

Has anyone heard of this issue before? I haven't heard of any but the early iMac G5's dying strangely like this.

Hopefully we can get 'er fixed!

 

[Gamer9430]

I'm guessing the cheapo capacitors have finally given up. That is indeed a common issue with iMac G5s since Apple was trying to cut costs by using budget capacitors that will likely fail in the next few years if they have not yet already. Only way to fix it is to crack it open and replace the faulty capacitors (better yet, replace them all) and it SHOULD work again. Another solution is to try sticking the hard drive in another computer and see if it works on there.

One thing you could try to see if its the machine or if its the OS install is to hold down T while turning it on, putting it into Target Disk Mode. Let it sit for some time and see if it freezes (the FireWire logo will stop moving). If it does, its likely either faulty RAM or the capacitors like I mentioned above. In that case, try replacing the RAM and see if that fixes it. If it doesn't fix it, then its likely the capacitors since a faulty HDD or Install wouldn't affect TDM.

If it does not while in TDM then it may be a faulty OS install or Hard Drive (unlikely given that I've never heard a faulty HDD do that to a computer). If that's the case, then you'll need to try and back up your files and then reinstall OS X Tiger or Leopard, depending on what you're using and see if it works after doing so. If it still fails, then I'd suggest replacing the RAM and test, and then if it fails still, replace the HDD and reinstall again. If it STILL fails, then its likely the capacitors or some other outlying issue.

Hopefully that helps!

 

[MattA]

I hadn't heard that the capacitor problem also happened with the 2nd generation units. I can easily check it out, though. If they are bulging, I'll have to source some and replace them.

The unit has 2GB of memory in it, but it hasn't had any kernel panics or anything like that. I'm not going to say the memory isn't at fault, but it sounds a bit more like the logic board is at fault. I'll have to pop it open and do some troubleshooting. Hopefully I can resurrect it easily enough.

 

[for this]

I'm guessing the cheapo capacitors have finally given up. That is indeed a common issue with iMac G5s since Apple was trying to cut costs by using budget capacitors that will likely fail in the next few years if they have not yet already.

The failed capacitors in iMac G5s seem limited to a bad batch from Nichicon.
The incident was called "Capacitor Plague". It didn't affect only Apple but also
Dell and other major computer manufacturers around 2003 to 2005.

Nichicon is one of the best brands around, certainly not a cheap brand.

BTW, while we're at it, MDD's PSUs have quite a lot of cheap/lesser brands of capacitor
in them (Ltec, CapXon, Teapo). And they failed on me, specifically Ltec and Teapo.

 

[Gamer9430]

The failed capacitors in iMac G5s seem limited to a bad batch from Nichicon.
The incident was called "Capacitor Plague". It didn't affect only Apple but also
Dell and other major computer manufacturers around 2003 to 2005.

Nichicon is one of the best brands around, certainly not a cheap brand.

BTW, while we're at it, MDD's PSUs have quite a lot of cheap/lesser brands of capacitor
in them (Ltec, CapXon, Teapo). And they failed on me, specifically Ltec and Teapo.

Thanks for the clarifications. I'm not too knowledgeable on the iMac G5's Capacitor Plague other than knowing it's a common problem. Being that it was a common problem, I figured that may be the cause of OP's problems with his unit.

 

[ITguy2016]

I hadn't heard that the capacitor problem also happened with the 2nd generation units. I can easily check it out, though. If they are bulging, I'll have to source some and replace them.

The unit has 2GB of memory in it, but it hasn't had any kernel panics or anything like that. I'm not going to say the memory isn't at fault, but it sounds a bit more like the logic board is at fault. I'll have to pop it open and do some troubleshooting. Hopefully I can resurrect it easily enough.

I think bulging can be too strong of an adjective for the problem. I've seen faulty capacitors that required a real hard look to determine if they had failed. The tops were just slightly raised and could easily be mistaken as OK.

 

[MattA]

Well, after troubleshooting this machine for awhile, it finally quit booting altogether. After looking into it a bit closer, it seems the power supply was on its way out. I swapped it for a known good one from ebay ($15), and we're back in business. Time will tell if this is the only problem, but so far, so good!