Tech Tip:FireWire Connections


By Craig Anderton

 

When FireWire (IEEE-1394) connections first made the scene, one of the claimed advantages compared to SCSI was that you could "hot plug" them - in other words, while power was on to a computer and peripheral, you could unplug the FireWire connection and plug it into a different powered-on peripheral. If you tried that with SCSI, it was fryin' time for sure.

 

But evidence is emerging that while you can hot plug most of the time – maybe even 99% of the time – there are still some situations where hot plugging can fry your computer’s motherboard, and possibly even the peripheral you’re trying to connect to it. The main failure mode seems to involve peripherals that grab power from the FireWire port; plugging them in can cause a momentary power surge, as components like capacitors charge up and semiconductor devices switch on.

 

Although the odds of problems happening are remote, they can happen. Unless you want to gamble on an expensive repair bill, observe the following rules:

 

  • Power down your computer and peripheral before connecting them via FireWire.
  • If the FireWire peripheral has an on-off switch (i.e., its own power supply), after making the FireWire connection turn on the peripheral first, then turn on the computer, unless the peripheral’s instructions recommend otherwise.

 

Sure, it’s a little extra hassle to power down and power back up again. But if it saves your motherboard, it's worth it.