There are a few more possible causes to consider before you start looking at well-documented issues and troubleshooting steps discussed in Lessons 17 and 18. These are less-than-obvious factors that you have to train yourself to look for as you continue building your system.
The environment in which your edit bay is located has an important impact on how well your system works. Computers don't respond well to extremes of temperature, voltage, or other factors that are more common than you might think in our technologically advanced civilization.
Although you see a sleek metal case on the outside, your Macintosh's processors and hard drives are generating heat inside, which it distributes and ejects with internal fans. But if the room it's blowing into isn't much cooler, then you can expect heat to become an issue. Ideally, working room temperatures should not exceed 75 degrees F.
Also, look around your room for less obvious heat influences. Is the Macintosh positioned near a window where it receives full sun? Is it positioned near an air conditioning vent, making it subject to rapid changes in temperature?
Another drawback of positioning your computer near air ducts is that the Mac's air intake will pull in a higher-than-normal amount of dust. Not only does dust build-up increase the temperature of your Macintosh, it also can generate static electricity.
Cables and Wiring
Also consider what might be referred to as the physical plant, or the hardware interfaces of your editing station. This means any sort of connectors for hard drives or decks, PCI card input/outputs, or even the UPS power supply for your edit bay. Any hardware going into or coming away from the case of your Macintosh is an interface with the outside world, and will probably receive some physical abuse during its normal operating lifetime. Damaged cables and connectors are a leading cause of unexpected crashes, erroneous Timecode break messages, and Log and Capture failure.
Make sure your cables are easily accessible and in good shape. If you need to plug and unplug them on a regular basis, you might want to invest in cables that are better quality than those that come packaged with many third-party devices. Consider adding a FireWire hub or extender to your Macintosh to avoid repeatedly plugging cables directly into the Mac. In addition, extenders will boost the signal carried by the FireWire cable and may make performance more consistent.
When troubleshooting a system, make sure your power supply is conditioned and there is enough overhead in the circuit to safely run everything you have plugged in to the wall.
The public power distribution system is notorious for inconsistent delivery. In most homes and facilities, the rated 110 volts of AC can fluctuate anywhere from 90 to 120 volts. Computers are sensitive to changes in voltage and can crash or hang when power supply voltage fluctuates.
The only way to achieve a consistent current is through a power conditioner. Most moderately priced uninterruptible power supplies (UPS) contain a power conditioner, meaning that your Mac receives constant voltage from the UPS's internal battery rather than fluctuating voltage directly from the wall outlet. The battery itself is constantly charged from the wall outlet. Professional post-production facilities may have much more resilient power conditioners built into their circuit breakers.
Most UPS units also have a limit to the number of amps they can provide from the battery. In general, the more amps a UPS battery can provide, the more devices you can plug into its battery backup and conditioner, and the more it costs. Not sure? Add up the number of amps on the devices you have plugged in, and then measure it against the specifications on your UPS (and the amps that your circuit breaker provides). Most devices will have the number of amps they draw listed somewhere on the device.