About a month ago my iMac G3 running OSX Panther started booting up with a message to change Date and Time. Despite changing settings each time I boot up and clicking the lock to prevent further changes it reverts to 1970 every time it's switched on. What is the cause and more importantly the solution.

Sounds like you have a dodgy battery inside the iMac. It usually happens when the computer has been left for an extended period of time (ie. left in storage for a few months) or when the internal battery goes.

You might be able to try and reset the PRAM, but I'm not sure if that will help!

If the imac has been unplugged for a while, the battery could have run flat or ... your mac could have been spiked(electrical), causing it to loose it's parameter ram settings. date, time, monitor setting. start up holding down Apple+alt+o+f. you will enter a dos-like mode with a command prompt. type in the command: reset-NVRAM, then enter/return. next type in the command: reset-all, then enter/return. the mac will restart. now set the date/time etc. my test to see if it works is to shut the mac down for longer than 5 minutes, then start up. also test the battery by shutting down, then unplug from mains.. 5 minutes as well. if you till losing time, you will need to purchase a new battery. if you open the ram replacement hatch at the base of the imac, you will see the battery. it is 1/2 AA in size.

If it is the PRAM battery, and it kinda sounds like it - one can purchase them real cheap from Dick Smith, by asking for a: Tekcell 3.6 Volt Memory Back Up Battery - and yes - 1/2 AA size as Mctastic mentioned. Around $16 if memory serves.

Follow Mctastic's guides first though - (and if I may make a quick insertion - after the iMac G3 restarts out of the Open Firmware Commands: restart iMac with + option + O + F keys on keyboard as explained by Mctastic - after Restarting and restting the right Date & Time, and shutting down for 5 minutes - DO pull out the iMac's Power Cord at the same time. This utterly drains it of electricity, thus allowing you to see on restart, whether or not the Date & Time have gone back to 1970 - in which case - yes - new PRAM Battery.

Depending on whether you have an iMac G3 with a CD-ROM that has an ejecting Tray, or simply a CD Slot that draws CDs in automatically, I'm sure we can dig up a PDF manual with clear pictures on the replacement procedure - much easier on Slot Loading iMac G3s, than on the older Tray Loading iMac G3s.

Tell us how you fair with Mctastic's instructions.

ClockWork

PRAM batteries have a life of 5 years under ideal cirumstances on the average. They're 1/2 AA 3.6 volt lithium batteries and cost about 5 bucks (here in the states) at any decent electronics store.

Personally, assuming that's the original PRAM battery in such an old Mac, I'd just replace it as a matter of course.



Dave

resetting nvram here is stupid and unnecessary when resetting PRAM will suffice. (if it would help at all.)

There is a how to change batteries on the web on one of the battery resellers in the USA
Has lots of photos and all that good stuff, I will have look for it later tommorrow.

Magnetic screwdriver is a good idea . Time and patience is another .

jaycar has one of the lowest battery prices last time I checked

It is an easy job just a bit fiddly .

<div class='quotetop'>QUOTE(Jazarus @ Jun 26 2006, 02:11 PM) [snapback]188532[/snapback]</div>they are the one and the same. that is pram and nvram

<div class='quotetop'>QUOTE(ClockWork @ Jun 26 2006, 02:03 PM) [snapback]188523[/snapback]</div>thanks CW. i assumed it was later model imac, based on the installation of Panther. yes, these batteries, in my experience generally last 5 years, so based on this it's about time to replace. i won't assume anything more to be damaged just yet. :huh:
interesting the cuda battery costs $16. in South Africa about R20(about 4.8 to dollar). interestingly, so many replaceables here seem a bit expensive to me. i also visted the the new shop that opened at Bondi and found stuff to be expensive. this is off the topic, but i'm just curious.

Mctastic,

Well - one could always go down to a good ol' Apple Service Centre an' get charged $45 for the P-RAM Battery + it's installation cost ... ;)

(still.. gotta make a profit)

cw

True. one thing is here and in South Africa, Apple Centre's are well loved i thought i was getting away from that.
basically i believe in a little give and take. i give to the home user and take from the companies/formal businesses. this way all are happy individuals needn't be given any reason to give up their macs because of high maintenance costs. i happily bill an hour to do most work on a home users mac, but would bill every minute if it were as business/ad agency. this is all fair in the whole cycle...

m