04-10-2012, 04:29 PM

We have an iMac G5 20 inch in the studio and it's started making some odd noises. On start up there is a popping noise, like pop rocks. Once it finishes starting the popping occasionally continues, sometimes when not doing anything or running any applications. I noticed that if I zap the PRAM, the noise doesn't happen as much. When we try and sync our iPhone with iTunes, the popping really gets going, Pop Rocks on Speed, and then usually the sync freezes. Then when we re-start the machine is popping again. I thought it might be the battery, but the tell-tale signs of the time and calendar being inaccurate isn't there. I also thought it might be a power surge or problem with the power supply. Also, if we mute the sound, the popping still continues and it definately sounds like it's coming from the bottom part of the iMac. I hope this helps.Any thoughts before we bring it to the Genius' and they have a hard time (possibly) diagnosing the problem.

04-10-2012, 05:04 PM

Originally Posted by dogboy443

...or problem with the power supply.

This would be my guess...probably the power supply on it's last legs.

- Nick

04-10-2012, 05:25 PM

Agreed Nick, most likely the power supply.

04-10-2012, 06:17 PM

Do not know what it is but there sure is a lot of it about:-


https://discussions.apple.com/thread...t=15&tstart=44

04-10-2012, 06:21 PM

Popping noises in switching power supplies is usually a tell tale sign of failing electrolytic capacitors. Have heard that sound many times and when those electrolytic caps blow, it ain't pretty!

04-10-2012, 06:25 PM

Originally Posted by harryb2448

Do not know what it is but there sure is a lot of it about:-


https://discussions.apple.com/thread...t=15&tstart=44

That's for an Intel 27in iMac though. Although it may be a related issue.

04-10-2012, 08:19 PM

Originally Posted by chscag

Have heard that sound many times and when those electrolytic caps blow, it ain't pretty!

They can be "STINKY" when they blow as well!

- Nick

04-11-2012, 01:50 PM

Thanks fellas, looks like the agreement is power supply. I also thought so, but I appreciated all of your input. Time to tear it down and put in a new one.

04-15-2012, 03:18 AM

The iMac G5 was very prone to this issue as it ages. I'm in agreement with my colleagues that this is the likely issue. Make sure your backups are up to date!

04-24-2012, 08:49 AM

Hi, we took our popping G5 iMac to the Genius Bar so they could give us a free diagnostic. Once there, after we registered on-line, we were told they couldn't test the iMac because it was too old, however if they saw this on the appointment ticket, don't you think they would have called us and told us not to bother coming in? Also, their off-the-cuff opinion was that it wasn't the power supply, but the speakers acting up. They suggested we open the back of the machine and disconnect the speakers and see what happens, however the popping noises aren't effected by any volume changes we make so how can it be the speakers??? We're going to look at the speakers, and still order a power supply. Not thrilled with our local Genius'.

04-24-2012, 01:23 PM

The lack of response by the genius bar is likely because they have no experience working with older Macs. Take our word for it and replace the power supply. The speakers are not very likely to cause that popping sound.

04-24-2012, 02:46 PM

Definitely agree with chscag. Most folks can tell the difference between the "static-like" popping that can come from speakers...and "other" popping...which is almost 99% the power supply.

Popping in a computer wouldn't be coming from anything else.

- Nick