Mac Plus – Clock and Settings Don't Keep After Shutdown

#1 Wed, 4 Mar 2015 - 07:58

Hello – I have a Mac Plus that won't save any settings, such as the time, date or mouse tracking. I replaced the PRAM battery on the back of it with a new one, but it still won't maintain it's internal clock after I shut it down for the night. What could be wrong? Is there something on the logic board that could have gone bad? It's not the end of the world, but it's annoying and I'd like to find out what it is.

Thanks.

#2 Wed, 4 Mar 2015 - 09:26

So you did replace the battery with a similar 523 type 4,5v and cleaned the contacts of the holder?
Because it seems the battery doesn't do anything in your case.

#3 Wed, 4 Mar 2015 - 12:42

If there is corrosion on the contacts maybe the leads on the battery box are corroded through. Might need to open it up and see. Or your new battery is not new and it's dead. It's not a AA it's bigger and longer.

#4 Wed, 4 Mar 2015 - 23:49

Yes, the battery is a type 523 4.5v. It's the one in the attached photo. I got it from Amazon: http://www.amazon.com/gp/product/B005AW9YGE/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1. I know the battery is good because I checked it with a voltmeter.

I'll have to take a close look at those contacts. If that seems fine, is there anywhere else that I should Iook?

Thanks for the suggestions.

#5 Thu, 5 Mar 2015 - 00:30

You may need to crack the case, and use a multimeter.

Have the battery installed, Then meter the voltage from the analog board, and trace it through. if it stops at the solder joint where the battery holder is, Then you know its the holder. But if its good, follow it through to the logic board. its being lost somewhere.

#6 Fri, 6 Mar 2015 - 19:42

So it looks like the upper contact has a fair amount of corrosion. You were all correct! I tried cleaning it but it still doesn't seem enough – the date still isn't saving. What's the best way to clean them up? Tips? I'd like to make sure this isn't the issue before taking the next step. My multimeter skills don't extend too much beyond checking batteries. :I

#7 Sat, 7 Mar 2015 - 17:33

It was the corrosion. White vinegar didn't work so I had to resort to the Dremel with a wire wheel. It works as it should now. The clock, time and all the settings save after shutdown.

Thanks all!

#8 Sun, 8 Mar 2015 - 00:14

Awesome!