If your Quadra 605, Performa 475, or PowerMac/Performa 6100 series computer is giving you trouble, the problem could be due to a dead 3.6-volt lithium battery.

It has been documented that these batteries can fail well before their anticipated life of 5 years, and unlike previous Macs, the loss of the PRAM battery voltage in all three of these computer models can cause unusual problems with date and time as well as a loss of video signal. If your computer's date has reverted to 1/1/1904 or 8/27/1956, or your chooser and network preferences keep resetting, your battery is probably already dead. Many reputable service establishments often misdiagnose these problems as a bad logic board. For a long time Apple's own service documentation made no mention of these battery/logic board related issues. New logic boards had new batteries pre-installed, so in many cases a tech would swap logic boards, and in essence they were only swapping batteries.

Some Macintosh computers have clocks that lapse back to August 27, 1956 the birth date of Ray Montagne, the Apple engineer and programmer who designed the chip that holds the PRAM (parameter RAM) on those models.

Quadra 605 & Performa 475 Battery replacement instructions:

If you have a voltmeter you could check the battery to verify that it is bad. The battery can be tested while still installed in the computer, so you can see if it needs to be replaced or not.

To replace the battery, first unplug the Quadra 605. Open the case by lifting up on the two plastic snap-locks on the upper rear edge of the top. Carefully lift off the top. Touch the top of the power supply with your finger, to discharge any possible static electricity (and try not to touch any chips, wires, etc, while you are working - anything except the battery holder and the battery). The Lithium battery is in a small black rectangular holder on the motherboard, just behind the hard drive. Before doing anything else, note the POLARITY of the battery. Every battery I have seen is installed so that the positive (+) end is to the left, and there is a small (+) printed on the inside of the plastic holder to indicate this.

The holder has a snap-on plastic cover on it, which must be removed before the battery will come out. Use a small screwdriver to carefully pry out the latching fingers of the plastic cover, one end at a time, just far enough so that the plastic cover will slip up and off of the holder. Then the battery can be easily lifted out.

MacBattery.com has the battery you need to fix this problem. www.macbattery.com. They sell it for $8.79 including First Class shipping via USPS.

While our popular 3.6-volt 1/2AA battery is most commonly sold for use as the PRAM - Clock battery for desktop Macintosh computer systems, they can also be used in the following:

Alarm Systems (remote transmitters) for the following brands:

ADT, ITI, Radionics, and Visonic

Dive Computers:

Note: Please read the battery replacement warnings in your user manual. Most dive computer user manual's recommend that you have an authorized dealer install this battery for you.

Aladin Dive Computers, Aqualung Monitor 1 & 2 Dive Computers, Dacor Dive Computers, and Suunto Favor Dive Computers

Other uses:

DogWatch 3000 Invisible Fence Systems

Reversing Instruments X Series (RTM 4002 X, RPM 2000 X, RPM 6000 X and RPM 10000 X)

Check out our battery part number cross-reference guide below to see if your battery is listed. If your battery's part number is listed below. Our 3.6 volt battery will work for your application, and will likely have a higher rating.

ANSI: 596-589 Electrocheml: 3B26TC, 3B33TC, 3B955TC Jbrol: 2904S Maxell: ER3S, ER4 RadioShack: T04 (23-026) SAFT: LS 14250, LST14250, LS3 Tadiran: TL5101, TL2150, TL2151, TL5101/S, TL5111/S, TL5112, TL5112/S, TL5151 Tekcell: SB-AA02 Varta: 6127, CR 1/2 AA, Others: VL1/2AA, T04/41, T04/51, LS3, ER14250 Apple: 922-1262, 922-4028