Imac Troubles

Have you checked the voltage of the motherboard battery?

No... and where exactly on the motherboard is that?
thanks!

should be in direct view of the hatch door. It is a purple battery. Like a miniature 'C' Sized battery. I think it is a camera battery iirc (i know that mine that were purchased were in a Camera Battery section). you might want to scoure online to find it. It would be cheaper that way. they are Litium by the way. don't go to radio shaft for it. They rip you off for like $45 for one of those.

Before you start, try resetting the PMU by pressing the button on the logic board marked "PMU reset". The location is shown on this page http://www.macgurus.com/products/motherboards/mbppcimacdv.php (board is rotated 180 degrees in that diagram from what it would be if the imac was face down)

If that doesn't work, the location of the battery is also shown on that page.
But you might be able to get a multimeter in to measure the voltage without the case off. Open the ram cover, look up inside it and you can see it. They're almost always purple. It should read 3.3V to 3.7V.

headgap sells them for $6.88 including shipping

It was completly stone dead,
i guess i found the problem!
only problem now is that i dropped a screw into the case and cant get it out! :S ha ha so is the batter under any other names? aka energiser? or does it have to be just like this one called a TADIRAN?
Thanks a lot

it's a regular battery that you can get for some Camera's. Apple did not make it name brand specific. There are others out there, including Energizer, Duracell, and many others. you just have to find one with that form factor. Currently, I have a Duracell in my iMac DV, as the last one went out. I also had an Energizer in a the PowerBase that I sold themike, and it used the same type.

I have no idea y apple stuck with that type of battery. Maybe, it just offered more standbye time, as it can be unplugged longer without losing data for the Firmware.

The specs you want are a 1/2 AA Lithium 3.6v battery. Otherwise, it doesn't matter on brand. There are 2/3 AA and full AA Lithum available, so check the size for sure before you buy it. If you mention it's for a Mac clock battery or PRAM, most places know what you want.

or just go here and buy this for $6.88 including shipping this is where i got my battery

PRAM battery

i would buy one anyway's if its old that is good you found what was wrong.

Should i be worried about the loose screw hangin out in my case somewhere?
is it going to fry my computer?!!?! :S ?
Thanks

There is a chance that it could. Did you drop one of the mobo cover screws into the monitor area, I guess? If so you can turn it upside down so the screw falls on to the plastic. Then use a magnetic tipped pickup tool to get it out. It's dang near impossible to shake/turn/tip it out of an iMac. If you don't have/can't find a magnetic tool, a peice of tape on a pencil ro something might work, too.

Mac PRAM, NVRAM, CUDA/PMU & Battery Tutorial
http://www.geocities.com/texas_macman/pram.html

Cheers, Tom

Yea i droped a screw from the x-ray sheilding into the monitor plastic, i've been shakin it upside down and i hear it rattling but i cant seem to see it! some times it pops out onto the green plastic but other times it dissapears behind the white plastic!
it hasent shorted out yet, i'm using it as we speak so it dosent seem to be on aything important aka, motherboard! LOL well i'll keep on trying to scope it out.
-Thanks

Hey i got the switch pressed and it worked! but just for measure i picked up a new battery anyway to keep my clock workin right! Thanks