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Mac Pro CMOS battery

The CMOS battery in my Mac Pro was cracked. My friend was fooling around to replace it before I could finish trying to find how to in the instruction manual. He pryed it up and broke the metal contact. My computer seems to function OK without it minus an error with one App causing a restart. Is it ok to run my Mac Pro without this CMOS battery? Since the metal contact is broke i don't see a good way to fix it.

I can't help you there. I suppose if you can find enough of the broken contact to which you might solder a lead, then you could fabricate a separate holder for the battery. Otherwise, you're looking at replacing the board.

No. The battery is not a CMOS battery rather it protects an area of RAM called the PRAM that stores important information such as selected boot drive, monitor configuration, etc. The battery is a 3.5 volt, 1/2 AA sized lithium cell you can purchase at Radio Shack or battery vendors.

Understandable but the metal contact is broken so lol guess I am out of luck, and have to deal with a malfunctioning computer. I have tried to buy a battery and electric tape it in but the heat from my graphics card i believe keeps that from happening and the only way is to lay down and hope it makes contact. I know of no other way to fix the CMOS battery holder.

On newer Mac Pro models, they have used a coin cell CR2032 3 Volt Long Life Lithium battery, half-hidden behind the graphics card slot.

EDIT: On really old Macs, (5500 and 6500 series) they used yet another battery, and it cost about US$25 for a replacement. It was very tempting to just substitute a battery holder and a few AA or AAA batteries -- you just had to make sure they do not get run all the way down, because they leak when they run down to zero.

I can't help you there. I suppose if you can find enough of the broken contact to which you might solder a lead, then you could fabricate a separate holder for the battery. Otherwise, you're looking at replacing the board.

Ahh, not aware of that. Mine is original 2006 model.

FYI, Kappy, the old PowerMacs used that kind of battery. The Mac Pro uses a BR 2032 coin size battery (at least that is what my manual says).

Edit: Getting slow in my old age.

Message was edited by: Martin Pace

Ya I am afraid to solder it for this current moment due to the potential of damaging the board. And a replacement might cost up towards $700 which is halfway to a new computer so that probably won't happen

Hi Matthew,

did you find some solution. I have same problem as you and dead PSU as well...

Thanks so much man!!!! Somehow my battery went AWOL and after digging all over Google I couldn't find this except on your reply.

It will function pretty well without a CMOS just make sure you "slide" it out. As far as a dead PSU that is your main problem here. Mac Pro Repair - Superdrive and Power Supply Removal - YouTube watch this video I would say take it out and try to match the model number and wattage up with a replacement PSU. I am pretty sure it is a modular power supply. A bit slow on this response I hadn't been reading my secondary email over the holidays. Also a PSU repair is anywhere between 60-200 usually depending on the model and type. Also this may be one of the easier repairs to get done. / do yourself. CMOS battery might function if you electrical tape the contact on and lay your computer on its side. I have taken apart my Mac Pro once down to the processors, and it was a pain in the butt to put back together and piece all the things in there correctly. The only other way I can think of is trying to manually put a new CMOS casing on your MOBO which requires taking your logic board out complicated process not worth it to me at the moment for an old computer. Just pop a new PSU in if possible and deal with no CMOS battery in it until you can afford a new comp. I play high end video games without a CMOS battery like Skyrim on bootcamp, and WoW works fine for me. Occasionally misfunctioning CD-ROM and sometimes a computer that doesn't want to shut down properly are my symptoms, but it is surviving like a champ.

remember the CMOS battery you can buy at a local store even walmart etc. just match up the number you find on  the front of your battery.

Here is YouTube link to my replacing the broken battery holder on a Mac Pro 1.1. I relocated the holder to the outside and left the broken one in place. Use of silver expoxy solder enabled me not to have to hot solder the wires to the logic board.

https://www.youtube.com/watch?v=hx_4zq8U6U4

Hi Matthew, did your fix work?  My mom just did this same thing with her Mac Pro 2006 model. I included some pictures.   The metal spring clip on top broke off AND the battery holder broke off flush on one side and up above on another.  I can't do what Gregory Speck did in his video with wires because there isn't a holder left in place to attach wires on the flush side.  From what I'm reading, using epoxy solder underneath the holder isn't a safe option to reattach it.  Is that correct?  Is this board ruined now?

Here is the top of the holder, including the broken clip that broke off at the square:

And here is the holder underneath. 

Any and all suggestions or advice will be appreciated. 

I'm not sure what to tell you except that the computer will function without it, and that it isn't worth the risk of fixing. You could try putting a new one on it by taking the entire logic board out of the case, but i'm pretty sure its built into motherboard and made not to be replaced. A new logic board costs almost as much as a new comp so.

最後更新：2017-09-26 02:30:20

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