G3 Blue & White won't shutdown

[DonkeyMe]

I recently updated Mac OS X to 10.3.9. Ever since then my Mac won't shutdown properly anymore. At the moment of Power Off it restarts within a second. I already zapped the PRAM but that doesn't help. Now I have to press the power button within that second but I don't think this will be any good for my beloved Yosemite.

Specs:
G3 400 MHz
768 Mb memory
6 Gb System partition on IDE HD

[mac.friend]

Hi,

I noticed the same behavior at my G4/400 after installing the latest Java Update for 10.3.9. No possibility to shut the computer down or logout...

Only if I login as a second user (I created a second account for my wife a few month ago), I’m able to turn it off. Still don't know the reason for this behavior....

[DonkeyMe]

Hi mac.friend,

I've done as you suggested, I've created a new user without the 10.3.9 and Java update, but it doesn't make any change to the situation. Sorry. I hope I can fix this, it's bothering me and also that I cannot grasp the reason for this behaviour ticks me off.

[ElDiabloConCaca]

Got any USB devices (other than keyboard/mouse) or possibly a USB hub connected? Try running without any external USB or FireWire devices and see if that helps... USB devices are notorious for causing this kind of problem.

Also, are you using the stock keyboard and mouse, or some 3rd party combo?

[DonkeyMe]

You're good at this! I disconnected the three devices (Logitech mouse, HP scanner and Canon printer) and used the old ADB Wacom tablet to control the Mac. Now it shuts down properly. Thanks. (I wonder if re-installing those three devices will do the trick, I'd like to use them you know). Thanks for solving the mistery.

[ElDiabloConCaca]

No problem -- next time you've got a few extra minutes to experiment, just try different combinations of devices connected to the computer to narrow it down to the culprit.

Also, if you're using any kind of USB hub, those are known to cause problems sometimes. On that note, always connect your main input devices (keyboard/mouse/graphics tablet) directly into the USB ports on the computer, instead of plugging them into a hub (if this applies to your situation). The keyboard should be in the port on the back of the computer and the mouse should be plugged into one side of the keyboard.

It may also be a matter of obtaining an updated driver, if there's one available.

I hope that helps narrow it down!