Q: My PowerBook is always clicking about something or other. It drives me crazy. What is all that clicking?
A: Actually, you’re hearing two different sets of clicks.
The clicking that comes out of the PowerBook speaker is the machine’s circuitry trying to do you a favor. After any sound has played, the Mac cuts off battery power to the speaker, thus blessing you with a cumulative few extra minutes of working time. The little click you hear is the juice being turned off to the sound chip and speaker.
The other click you hear, primarily on newer PowerBook models, is the IBM-made internal hard drive. (Yes, that’s right: Apple buys hard drives from IBM, of all companies.) After being accessed, the hard drive pops its heads aside, causing that loudish click.
CASE HISTORY
Beware of exploding batteries
We all know that computing can be dangerous to your health. Your wrists can get carpal-tunnel syndrome. Your body can be bombarded by ELF radiation from the CRT monitor. You can be mugged by a thug with his eye on your laptop.
But in 1992, Apple announced what had to be the weirdest potential hazard yet: spontaneously combusting PowerBook batteries. Apparently the company had two reports of charged-up batteries igniting briefcases when some metallic object accidentally touched both battery terminals.
As of that moment, Apple began including a plastic box with every PowerBook battery. (The Duo battery isn’t prone to this potential firestorm; its circuitry automatically cuts off the juice when it’s not inside a computer. But it, too, comes with a cute plastic box, just for aesthetics.)
In 1995, Apple discovered an even more embarrassing (and potentially life-threatening) PowerBook battery problem — one that couldn’t be solved with a simple battery cover. Shortly after the 5300-series PowerBooks were released, Apple technicians found that the lithium ion (LiIon) batteries included with those models could overheat and explode because of a buildup of pressure inside the battery cells. (They discovered this when two LiIon-equipped PowerBooks actually went up in flames at Apple’s main campus in Cupertino.) The result was Apple’s first-ever recall of a computer; about 1,000 of the PowerBook 5300-series machines were hauled back in from the field.
Apple replaced the LiIon batteries with the old-fashioned NiMH batteries and provided a new system extension that teaches the 5300-series PowerBooks how to use the NiMH technology. The LiIon batteries’ debut was postponed for two more years — with the introduction of the PowerBook 1400.
