USB short circuit problem?

in Genius Bar edited January 2014
Hi, this is my first post. Apologies in advance if this subject has been covered in recent threads, but I'm up against a deadline tighter than a spider's ass. Thanks in advance for any suggestions!

Details: G4 + OS 9.0.1 + fully functional 7 port USB hub. Problem? Plugging the USB hub (connected to a printer, scanner, and modem) into the back of the Mac stops the keyboard and mouse from working! I've tried the old process-of-elimination thing with any number of combinations, all to no avail. I've tried two keyboards, two different mice, two different USB hubs... basically, I'm going nuts. Any ideas?

A million rubies and two of my daughters for the man with a plan!


  • Reply 1 of 3
    Is the hub self powered? or does it just plug into the mac with out a AC adapter? I think both USB ports are on the same power "bracket" if one is being "overloaded" it will draw all the power from the other port as well.
  • Reply 2 of 3
    The Hub is powered.

    The overloaded/power-drain explanation makes sense - I tried plugging two devices into the back of my Lacie monitor; but my keyboard didn't want to work from there either, nor did any other device (trying to grab the scanner from within Photoshop, for example, only gave me a "scanner not present" message).

    Whatever I do, wherever I plug things, I can't get everything to work at once. Totally confused as I can't even seem to be able to isolate the problem to one external device.

    Of course, re-installing the OS (or upgrading for that matter) may well solve the problem, but maybe it won't if it's a hardware issue as opposed to a possible driver issue. I swept Tech Tools Pro over the HD, but that came up blank...
  • Reply 3 of 3
    If you have a G4 tower, you could get a PCI USB card. That should solve your problem. If not, i'm really not sure whats happening. I guess you could always wait until Monday an get a new G5?!
Sign In or Register to comment.