[FAQ]Powerbook G4 Not Detecting Any Usb External Hard Drives


To a macosx client's question, another client (so not a tech) has made the following answer

Q: i just recently bought a new powerboook G4 1.67ghz. Unfortunately i have tried 2 USB EXTERNAL hard drives and neither is being detected by the laptop..what to do? ipod works fine.

The reason the newer powerbooks won't work with USB 2 hard drives is because these machines are limited to a very paltry 500ma loading on the USB 2 bus. 2.5" USB 2 hard drives draw close to +580ma. So if powered by the bus, the leds might illuminate but there isn't enough amperage to spin up these smaller harddisks. The only solution i've found so far is an external PSU (assuming the drive even allows one to be connected!). This is majorly stupid of Apple..and makes no sense at all. What's even more inane is that they've known about the problem since the introduction of aluminum powerbooks..but made no attempt to correct it! One other thing, all other machines to include Mac iBooks, PC laptops and any Mac or PC desktops work fine with 2.5" USB 2 hard drives using only the bus as a power source..and this includes my G5. Why Apple made this glaring blunder..and then allowed it to persist through at least one generation is one more indication why they are rapidly sliding down the slippery slope in my 'be it so humble' estimation! Btw, iPods draw around 500ma, just within tolerances...which is why they work! This really annoys as it means the only way i'll ever be able to get my ultra cool, ultra convenient USB 2 drives to work is by hooking up yet more of those bluddy wall warts! The real irony is that the firewire bus has loads of available power and can handle quite a number of drives, peripherals, etc. Both the USB 2 bus and firewire are supplied by the same power supply! So go figure! One possible but really awkward solution might be locating and then tapping into the +5 and -5 VDC firewire power using a male firewire plug and hooking that up to a cable with a regular PSU connector at the other. Not for the faint of heart though and should be fabricated by an expert.


Re: G4 Powerbook not detecting USB2 drives:

Philippe, you are brilliant. I couldn't get a USB drive I made out of an old Powerbook drive to mount on my G4 Powerbook. Then I stumbled across your tip. Once I plugged the drive into my iBook it worked beautifully. Thank you.


Philippe, I second the claim that you are a genius!! This was driving me absolutely INSANE. I went through countless USB external enclosures, until I finally gave up and just bought a Firewire enclosure.....works perfectly. Thank you though, for clearing up the reason the USB enclosure would not work.

I also agree with you, this is REALLY stupid on Apple's part to produce a laptop with such limitations to such a universal device. Thanks again.....