Troubleshooting faulty FireWire connections
Troubleshooting faulty FireWire connections
Keeping tabs on proper FireWire use Making sure that everyone in your organization is properly using FireWire ports is key to avoiding failure. Bryan McGill, a Macintosh administrator, writes:
"This is in regards to the Firewire problem you posted 2-19-03. Our company has experienced Firewire failure on a PB G4 667 and on a G4 DP 450. Users' lack of knowledge about how to properly plug and unplug a firewire device seemed to play a big part in the failure. I believe in each case, it was being used to connect to other Macs. We now supervise users using firewire and have informed them of the proper steps to take while using Firewire with their Mac. Haven't had any problems since. However, I agree there is an issue with at least these models - using a Mac's Firewire really shouldn't be this unforgiving."
One of the first things to keep in mind is that you should never attempt to force a 4-pin connector into a 6-pin port on a device. Also, before connecting a 4-pin plug to its port, align the two ends visually and do not force them if a fit is not apparent. In addition, some cables lock onto the port, and you have to pinch the connector's sides before pulling on it. Cables with 6-pin connectors carry power and data from one device to another. Four-pin cables carry data only.
Also, if you are using FireWire target disk mode, make sure that the target computer is turned off before beginning the process (not powered on then restarted). Turn off the target computer before pulling out the FireWire cable.
Burning smell? Disconnect immediately If you smell a burning aroma coming from your Mac, sometimes accompanied by smoke, disconnect all FireWire devices immediately, shut down your system, and head to an Apple authorized repair center.
Your ports may already be fried, but you can quarantine the damage to some degree by immediately shutting down. Stephen Kennedy offers a case example:
"My fire wire port on my Titanium PowerBook G4 burnt out last week. I plugged in another computer hoping to mount the hard disk using the target disk more function. After a minute or so I could smell a burning smell and realized it was my G4 FireWire port. Apple have since taken it from me and repaired it for free. A new logic board was needed."
Power, but no data transfer Oddly, a number of damaged FireWire ports will still bus-power devices, even though the devices will not be recognized by the Mac they are connected to. This was the case on our in-house Power Macintosh G4 450 Dual Processor. In fact, at one point we used a FireWire cable to bus-power an external WiebeTech FireWire drive that was also connected via the USB port for data transfer.
Eric Azria's Titanium PowerBook G4 400 (which coincidentally is the Mac model for which we've received the most FireWire failure reports):
"I had a PowerBook G4 Titanium 400. After 18 months, I got a dead firewire port, using several FireWire hard drives including a VST ZIP 250 drive. The port is still giving power but nothing is recognized. The FireWire bus is recognized in Apple System profiler."
Pressing the motherboard reset button In cases like the one above (bus power but no data transfer capabilities) and some others, a reset of the motherboard may solve FireWire failure problems. Ron Pfieser writes:
"I have recently had a problem with my Power Mac G4 DP/533, where both of my FireWire Ports went dead without any apparent reason. PRAM zaps, OpenFirmware resets and the like didn't help. So I shut down the system, opened the Power Mac's case and pressed the motherboard reset switch for a few seconds. After hooking everything up again, both FireWire ports have been functioning flawlessly ever since."
Isolator cable: The solution? MacFixIt reader Dave Green says that after ten FireWire failures across various Mac systems in his organization, he found the solution - a FireWire isolator cable.
"A simple isolator firewire cable (missing the power + pin 6) inserted at the G4 port fixes the problem, and prevents the failure in my experience. You could (though I would not recommend it) modify a regular cable and simply cut the power wire as a stopgap. FireWire Depot is the only place I know that carries them.
"I had a few custom made to test the fix back in November - no failures since.
"This isolator cable also fixes problems in long chains of many separately powered FireWire devices. (I have a 25 drive chain working fine under Mac OS 8.6 using these same isolators to prevent noise from the interconnected power lines from causing problems in long chains or where major differences - +10% on 1 supply and -10% on another is worse case - exist between adjacent FireWire devices.)
"The problem is a holdover from SCSI I,II and III where term-power caused similar problems in SCSI chains - due to multiple power supplies being connected through the FireWire cable."
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