Help with Performa 575

Those macs have a slide-out processor card. You may find that its parameters do not persist, or it gets cranky about starting up, or it forgets the date&time. If so, you may need to replace the PRAM backup battery on the slide-out motherboard.

If you want the longest life before you have to change that battery, think of the rocker switch as a "service" switch, and leave it on. Shut down from the menu, and start up with the keyboard button.

That "slight noise" is a very important diagnostic tool. It tells you the power supply is working.

The AppleSpec is here:

http://docs.info.apple.com/article.html?artnum=112239

Says it takes a comm slot card (for Ethernet). They are readily available on the used market for under US$10. Buy a genuine Apple one, or be sure to get the drivers with it, as half the makers of these cards are out of business.

Here is an example from a very trustworthy character who calls himself "Old Mac Milt":

Apple Comm Slot I Ethernet Card - 10 Base T

His prices are a little higher, but he stands by his product and can be very helpful if needed. I have done business with him before and found him very helpful and supportive. I have no financial interest in his business, I just know he won't cheat you, and he explains what he is selling and helps you get it to work.

Message was edited by: Grant Bennet-Alder

I have an LC580 that is a little cranky about starting and if I flip the switch a few times it usually boots. And you may want to pull the back cover, remove the two screws holding the backplate on and pull the logic board out and slide it back in to make sure it's getting good contact.

If it still isn't turning on for you, you have to plug in a Mac keyboard and press the button with the little triangle on it. It's the button on the top-right corner. This is the way to turn on many (but not all) old Macs. Not sure how much you know about Macs, that's why I say this.

Your Mac will run fine with a dead PRAM battery. I have 20+ macs and not a single one has a good PRAM battery.

Not all Macs will run fine with a dead PRAM battery. Some problems are merely inconvenient, such as recording the wrong date & time, but others may have no video or refuse to start up at all.

This early article lists a number of models that may have certain problems, but there are many more models and many more problems not listed. Many posters here have complaints that end up being a dead PRAM backup battery. It may be the most common solution.

20328- Macintosh Computers: Low Battery Can Cause No Video

I agree, I have rarely ever had a boot problem with a dead PRAM battery on many many macs over the years. I notice a lot of responses here are to buy a $12 battery and that's rarely the problem. During the installation of the battery other problems may be corrected without knowing it and gets attributed to replaceing the battery in error. (Such as loose connections)

Very few macs will not boot, or have video problems with a dead PRAM battery. The rest will just not keep the settings when unplugged.

Makes me wonder if some people here own Radio Shack stock 😉

I agree that this is kind of an expense that could be avoided. It is indeed a source of problems but usually you can zap the PRAM, PMU reset, or power on-off-on. On more recent Macs, most settings are brought back after booting (except date/time of course.).

Those 3 tricks (zap the PRAM, PMU reset, or power on-off-on) should be (and probably are) suggested before suggesting a new battery.

I know the Mac II had 2 batteries and one could prevent it from turning on, so I agree that there are exceptions.

<<I agree that this is kind of an expense that could be avoided. It is indeed a source of problems but usually you can zap the PRAM, PMU reset, or power on-off-on. On more recent Macs, most settings are brought back after booting (except date/time of course.).

Those 3 tricks (zap the PRAM, PMU reset, or power on-off-on) should be (and probably are) suggested before suggesting a new battery.

I know the Mac II had 2 batteries and one could prevent it from turning on, so I agree that there are exceptions.>>

Exactly.... Why spend $12 on a battery to get the Mac to boot if it's not needed. Better yet, test the battery to see if it's at the full voltage, or at least close before even considering a new battery.