iMac G5 (PowerMac8,1/A1058) Boots to Apple Logo, fans spin up

[!!!]

So I recently got an iMac G5 from a goodwill with nothing but the iMac itself and the power cable. Whenever I try to boot it up, it powers on and displays the Apple Logo, but doesn't progress any further. The fans also spin up quite a bit.

I'm able to get into the drive selector (option key at startup) which displays Macintosh HD as an OS X startup volume. I'm also able to get into OpenFirmware just fine. I also tried clearing the NVRAM. I took the back off, cleaned out the dust and I didn't see any capacitors that look busted (in researching I discovered this might be the issues). I also took out the HD and connected it to my 2018 Mac mini and it just said it was uninitialized, which is weird considering I had no issue mounting a drive from a different Mac from around that era, but it does properly show up in the iMac's boot menu.

Does anyone have any idea what the issue could be?

 

[RogerWilco6502]

Sounds like possibly a corrupt or dying HDD

 

[!!!]

Turns out it was just something wrong with the HD. Booted into the recovery DVD, ended up not being able to repair the disk. Wiped it and did a clean install, seems to work fine.

 

[nikey22]

The capacitors will still be a problem here. There are 24 1800μF 6.3v, and 5 1000μF 16v that need to be replaced. If these are the original ones, they will surely fail. There was a problem with electrolyte formula in the caps during this time-period.

You will need a soldering iron that is 60W. This is a multi-layer board (acting as a huge heat-sink) and the solder used is lead-free and has a higher melting temperature.

 

[RogerWilco6502]

The capacitors will still be a problem here. There are 24 1800μF 6.3v, and 5 1000μF 16v that need to be replaced. If these are the original ones, they will surely fail. There was a problem with electrolyte formula in the caps during this time-period.

You will need a soldering iron that is 60W. This is a multi-layer board (acting as a huge heat-sink) and the solder used is lead-free and has a higher melting temperature.

I second this, I have no experience personally with these systems, but I do know the capacitors are prone to failure.

 

[tigerintank]

Alternate take here - if it works, use it till it doesn't then decide whether to attempt a fix.

My 2.0 ALS had bulging PSU caps, with random power off as the symptoms. I replaced the psi caps, lasted a few months iirc before psi made a pop sound and was done.

Replaced the original psi with a PC ATX psi and iirc that lasted a fair bit longer before failing. Replaced it with a higher spec psi and it runs to this day.

No mainboard caps have been replaced or shown visible signs of probs.

 

[1042686]

Im in the "if it ain't broke don't fix it" camp.

I'm more inclined to upgrade the hard drive to a SSD as the existing spinner is squirrelly. The inside of those Imac G5s are really nice to look at too - much nicer than the g1 intel imac.