[Ti] 1.5ghz Powerbooks: Where is the PMU button?

[Kynan Shook]

Command-Control-Power is and always has been the preferable way to 
reset your computer.  On old ADB Macs, it sent a hardware reset signal. 
  USB doesn't have this reset pin, so it has to emulate this reset 
(which means that if the computer crashes, it probably won't work - 
tell me, what's the use of a reset switch that doesn't work when you 
most need it? ;-)).  PowerBooks, both pre- and post-USB, have always 
used Command-Control-Power for reset, as the connector is over a 
proprietary bus.  Anyway, you should NEVER be using the PMU reset 
button to reboot the computer.  I think part of the reason why they 
moved it under the keyboard (and now made it a keyboard command - much 
like it was a number of years ago) is because people were using that 
instead of command-control-power.  So, moral of the story: if your 
computer crashes, use command-control-power.

I'm almost tempted to not mention the PMU reset combo, just because the 
vast majority of people will never need it anyway...  But I suppose 
I'll be nice.  ;-) Shut down your computer, then press 
Shift-Control-Option-Power briefly, being sure to not press any other 
keys such as Fn.  Do not press it a second time, as that can crash the 
Power Management Unit.  Wait 10 seconds, and turn the computer back on. 
  The only time you should use the PMU reset is if your computer is not 
powering on, is only partially powering on, is having problems with 
either the battery or AC, has problems sleeping or waking, etc.  It is 
not intended to use for resetting after a normal crash, or for 
otherwise powering off the computer.

Another alternative to Command-Control-Power is to just hold down the 
power button for about 5 seconds.  Instead of rebooting, the computer 
will shut down forcibly.

John Griffin <jwegriffin at mac.com> writes:
> Every Apple Powerbook I have owned has possessed a button - either 
> under the
> keyboard (on motherboard), or on the back panel of the unit. This is 
> the
> first one that I have ever seen that seems not to be equipped with one.
> There seems to be no way of lifting the keyboard to gain access to the
> motherboard and there are no buttons on the case itself.
>
> The manual that comes with the machine makes no mention of such a 
> button (it
> did with previous machines). It does mention a new three-finger 
> procedure
> that I have not heard of before (Command/Control/Power) to reset the 
> system,
> but I can't thing that this does the same as pushing and holding the 
> PMU
> button.