View Full Version : iMac G5 (2004) SMU switch on logic board?
09-02-2009, 03:21 PM
I have a 2004 vintage iMac G5, 1.8 GHz, 1.5 GB Ram running Mac Os X 10.4.11. When I boot up (from the internal HD) the boot sequence is very slow and the fan blows loudly (the system eventually boots up). I have reset the nvram with no success. There is no SMU switch on the logic board - that I can see - only the on/off switch. Is there any other way of resetting the SMU?
Thanks in advance for any help - its appreciated!
09-02-2009, 04:29 PM
Google suggests this might be a photo of the inside of your iMac, showing the location of the SMU:
09-02-2009, 05:35 PM
The SMU reset is done with a very small, very inobtrusive black button. It doesn't even look like something you can actually do anything with, but of course you can.
Google search: site:apple.com iMac G5 SMU reset (http://www.google.com/search?q=site%3Aapple.com+iMac+G5+SMU+reset&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a)
09-02-2009, 05:38 PM
Also, iMac G5: How to reset the SMU (http://support.apple.com/kb/HT1767)
09-03-2009, 06:55 AM
The photo of the logic board is correct - alas I have only one switch (Power) populated on the PCB. I had read/tried the Apple SMU support article also - with no success. I'm beginning to think that I have an early release of the Logic board (iMac G5). Thanks for your help in any case.
09-03-2009, 07:11 PM
Trevor, just out of curiosity - what is the location of the black SMU switch on the logic board? - my Power switch is directly under the fans on the logic board and its color is beige.
Thanks in advance
09-04-2009, 09:03 AM
Oh, my mistake! It's black on all the Power Mac models I can remember, but according to the photograph below, it does seem to be beige on the iMac G5:
09-04-2009, 02:11 PM
Yup - its missing on my logic board! In addition, I have implemented the instructions in the Apple Support article (to reset the SMU) above i.e. shutdown and disconnect the power cord, wait 10 seconds and then reconnect the power cord whilst holding down the power switch This however does not reset the System clock upon rebooting - therefore the SMU is not reset. Would this be a correct scenario?
09-04-2009, 03:47 PM
It's not missing. You just have a newer model, which does not have that push button.
Just to repeat that reset procedure:
1. Unplug all cables from the computer, including the power cord.
2. Wait 10 seconds.
3. Plug in the power cord while simultaneously pressing and holding the power button on
the back of the computer.
4. Let go of the power button.
5. Press the power button once more to start up your iMac G5.
The clock should reset (to year 2000, I think), but if you have network connected as you boot, the system time may set correctly as soon as your Mac finishes booting. If you want to prevent that time setting, boot into Safe Boot mode by holding the shift key until you see the rotating gear under the Apple icon during boot. The time shouldn't set automatically then.
Anyway, it may not help your situation. Really slow boots often will be symptoms of a failing hard drive.
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