Mac g5 pmu reset button

I manually shut down my computer after 5 minutes. Jonathan K, who had success with removing devices, writes:. The basic test ran and allowed me to look at the test results. However, the intermediate tests, quit at the end and automatically restarted. Since I was running from the CD, all reports were lost. Some users who have been running into problems while optimizing volumes with TechTool Pro 4.

Once optimization is finished, journaling can be turned back on with the same tool. Reader Markus Altendorff has also posted a few excellent demo sound files, and provided a few informative comments:. After installing the CHUD tools Apple, Developer software , disabling "CPU Napping" some sort of power-down mode during idle clock cycles makes the chirping go away see below for more details - the chirping does not disappear completely.

My guess and backed by a friend of mine, former electronics pro and now IT Since disabling CPU napping results in the CPUs consuming a fairly constant current, the vibrations stop the magnetic fields in the coils remain constant.

iMac G5 Reset SMU: No longer termed iMac PMU reset button

The bad thing about this is that the chirping also shows at the USB and Firewire ports, causing trouble when you try to use this computer in a recording studio - the thread at Apple Discussions contains quite a few complaints about how the G5 is barely usable for audio production because of this. What makes these issues more than just annoying for some users is that some of the noises are transferred via USB and FireWire connections, and some are amplified by connected audio equipment -- reader Catherine Vibert reports that a "whining" noise is actually transmitted to the DIGI in Pro Tools via Firewire.

These issues make affected G5 computers unusable for digital audio work.

Original Poster Answers own question

Unfortunately, it's difficult for us to correlate noises with potential solutions because many people who have sent reports to MacFixIt have been vague about which noise their particular G5 is producing. There are clearly different problems and different solutions. If you send us email on this issue, please state which of the above "noises" your Power Mac G5 is producing and which, if any, technique reduces which noise. Full-blown fans We've also received a number of additional reports of an issue where putting the G5 to sleep results in the fans revving up to full speed which is startlingly loud if you've never heard it.

Sometimes the situation can be resolved by waking the G5 up and then putting it back to sleep; however, sometimes the G5 will refuse to wake up, requiring a restart. We had this happen once to our G5 here at MacFixIt. It appears that Apple technical support is recommending a PMU power management unit reset to some customers who are having fan irregularity problems.

We've also managed to scrounge up a few unorthodox workarounds, including placing a thick pad of paper underneath the G5 to prevent vibration:. MacFixIt reader Paul Burton is one of the handful of G5 owners who experienced a problem where the system goes to sleep, the fans rev to full speed, and the G5 cannot be woken. Of course, it was the first time he had heard of such an issue with a G5.

G4 shutdown/ restart problem

That said he suggested resetting the PMU pressing a button on the logic board inside the tower:. Meanwhile, Stan Goldberg found that putting a thick pad of paper under his G5 - which started making excessive noise after a few days of quiet operation - helped to dampen the vibration of the G5's case against his desk, eliminating one source of unwanted noise:.


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I was amazed how silent it was. Then after the loud rev up upon sleep occurred after about five days the front fan seems to have come on and makes a consistent humming fan noise and won't turn off. There is also high pitch sounds that come and go and seem to be due to vibration. Putting thick paper pads under the lower supports helped with the vibration transmission to my wooden desk. If Processor Performance is turned to Automatic or Reduced, the noise is quieter, but still noticeable to some discriminating ears.

Oddly or perhaps not the problem disappears when iTunes' visualizer is turned on for many users. A thread on Apple's discussion boards pertaining to this issue contains nearly posts. Apple has be unable to offer any solution other than to replace the power supply, with no guarantee that the replacement will solve the problem. The only way to stop them is to hold the power button for 5 seconds to shut off the computer.

The most widely reported successful repair procedure involves replacing the G5's power supply unit.

how to remove password mac, powerbook G4, macbook, G5... (factory reset) without disk (EASY STEPS)

Customers have been hit-or-miss in their success obtaining this repair from Apple. There are pops, clicks, sound dropout and something that I can only describe as digital 'wow and flutter' - I thought that had been consigned to history with the vinyl disc. However, as previously noted, this workaround only muffles the artifacts to an inaudible level in some set-ups. In highly sensitive, amplified sound environments, the chirps, beeps, and other strange noises are still noticeable.

Most reports indicate that the audio problems become worse after the G5 has been on for several minutes, or a processor intensive operation is taking place. I have two at work identical that don't exhibit that behavior, and when I ran the Extended Hardware Test, it worked fine.

Boy, do the fans get loud during those tests It booted and ran fine with the door removed. Apple Knowledge Base article holds the solution. It states:. Wargo says that as soon as he removed the plastic strips, he could successfully remove the aluminum door leaving the clear heat shield in place without freezing. There is a problem with some currently? Some users have had success eliminating this problem by using the age-old process of resetting PRAM.

CUDA / PMU IMAGES

MacFixIt reader Robert Cramer writes:. The procedure is in the Troubleshooting section of the G5 Manual. In this case, it may not be the actual zapping of the PRAM that is doing the trick. Performing the PRAM reset causes your Mac to restart continuously until you release the key combination. It may simply be the repeated restart that is allowing users to startup properly.

It booted up with the screen working for two days. On the built-in keyboard, press and hold the Shift, Option, and Control keys on the left side and press the power button and hold all of these down for 10 seconds, then release the keys. Connect the power adapter and then turn the Mac on normally. Portable Macs with removable batteries: Shut down your Mac. Disconnect the power cord and remove the battery. Press the power button, hold it for 5 seconds, and then let go.

SOLVED: Power Mac G5 won`t start - Power Mac G5 - iFixit

Put the battery back in, reconnect the power cord, and turn the Mac on normally. Although neither of these procedures is a guaranteed cure, both of them can solve a number of odd problems, and are worth a few minutes of your time before hauling your Mac in to see the local Apple Genius.

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