First-gen Intel iMac needs PMU reset all the time

[evilspoons]

My cousin's 2.0 GHz 20" Core Duo iMac (the first Intel one, if I'm not mistaken) constantly needs its PMU reset in order to make Bluetooth and the internal IR receiver work.

I turn it on sometimes and bluetooth is there and the remote works. Other times the bluetooth icon disappears and the remote doesn't function. To get it to work again, I have to turn the iMac off, unplug it for 30 seconds, and when I boot up it works again. (these are Apple's PMU reset instructions.)

The machine originally had 10.3, was upgraded to 10.4 who knows when, and just got upgraded to 10.5.6 via install DVD and then combo update to 10.5.8.

Unfortunately I think it still does it on my external USB hard drive, which is a 100% fresh install of 10.5 upgraded to 10.5.8.

Is there an internal battery that could be dead (like the BIOS backup on a non-Mac)?

 

[MTI]

Is there an internal battery that could be dead (like the BIOS backup on a non-Mac)?

Pretty much all Apple computers use a CMOS battery, even the iMacs.

 

[evilspoons]

Pretty much all Apple computers use a CMOS battery, even the iMacs.

Riiight, but would it being dead cause this problem? Would it also cause problems I'm not having, as a way to narrow down what's going on?

 

[MTI]

If the CMOS battery is truly dead, the simple test to verify is whether the time and date are correct when booting up, before the computer has an opportunity to check it on the 'net, either through an Airport connection or wired ethernet. If date and time are correct as before doing a shutdown, power plug out for 20 seconds, reboot, then it's not the CMOS.