Archive. This is an archive of the Apple Support Community. Discussions are being restored and soon you will be able to read and post here again.
beigebox
User level: Level 1 (28 points)

Power Mac 7600 enters low power mode when connected to FireWire hub

I have a Powermac 7600 running OS 9.1.


I installed a Firewire 1.1 PCI card which connects to an external drive just fine.


I have a 6 port Belkin firewire hub with it's own power adapter. There are other computers connected to this hub, all powered off. When I connect this computer to the hub (with or without the hub's power adapter), the computer goes into low power mode. This will happen if the computer is on or off before connecting to the hub. The drive still mounts up after this happens, but my concern is that the hub is causing a susbtantial power load on the PCI card, and this method is protecting the computer.


Question ... why is this happening?

Posted on Oct 16, 2026 6:28 AM

5 replies

beigebox Author
User level: Level 1 (28 points)

Oct 16, 2026 6:00 PM in response to beigebox

Jeff
User level: Level 6 (12,436 points)

Oct 17, 2026 3:59 AM in response to beigebox

beigebox wrote:
I have a 6 port Belkin firewire hub with it's own power adapter. There are other computers connected to this hub, all powered off.


You've got multiple computers connected to the FireWire hub? The hub is only intended to provide extra (powered) ports between one computer/host controller (via the hub's input port) and the peripheral devices (via the output ports). To avoid confusion, some hubs specify the port to connect to the computer, while the others are for the peripherals. Are you using a Belkin F5U526-APL hub? If so, there doesn't appear to be a designated "input" port on the housing. The Belkin F5U507 USB 2.0/FireWire hub has designated "to computer" ports. I have an older, Belkin 4-port, powered FireWire hub and the port intended for connection to the computer is clearly marked.

Allan Jones
User level: Level 10 (85,896 points)

Oct 16, 2026 5:18 PM in response to beigebox

For starters, what make/model is the FW card?


There are other computers connected to this hub, all powered off.


Have you tested with the other computers physically disconnected from the hub? Even if powered off, they may be drawing a bit of power. Desktop Macs of that vintage had a bypass around the power supply that let a 5V trickle current past the shut-down PS to maintain settings and preferences. I've never owned a Windows computer so don't know if they had a similar function. If only turned off, other computers could still be drawing a little power.


Have you cleaned the contacts on the FW card and its slot?


I may be the only other person here who still has a working 7600/132, but the only card in mine is an old ATI video 16MB card.


Just remembered. The 7600 has a daughter card as well as PCI slots. You might try removing and reseating the d-card to freshen its contacts.


We are traveling right now so I can't run down the hall to check for other stuff that might affect the 7600. Don't give up yet!



beigebox Author
User level: Level 1 (28 points)

Oct 17, 2026 7:29 AM in response to Jeff

The Belkin model is F5U526 and it has it’s own power supply.


I have four computers connected to it but only use one at a time. I have external drives located close to the hub for the purpose of using them according to the computer that is powered up.


I don’t see a designated input port for computers.

beigebox Author
User level: Level 1 (28 points)

Oct 16, 2026 6:02 PM in response to beigebox

I will single the 7600 to the hub to see if that makes any difference

Originally posted at discussions.apple.com/thread/256377257