Waking up a dead old iMac?

I’m trying to help a friend with an old iMac. I’m not exactly sure how old it is, but from looking at old emails my best guess is that it might be from 2009.

He rarely used it (he mostly uses his iPhone and iPad) but had been turning it on regularly until 6 months ago. I’m not sure what for and I’m not sure he knows what for. He’s not exactly a techie.

Anyway, 6 months ago, after the last time he used it, he unplugged it for some reason. Now it won’t start up. Pressing the rear button does nothing at all. No sound of it trying to start. Nothing.

I was reading here and there about leaving an old iMac unplugged for too long might hurt some internal battery. Is that a thing?

Is there anything he can do? I think at this point he wants to just make sure he connects to iCloud and that everything is backed up there.

It might be the battery, on the Mac Pro from 2009, I know that a low voltage from the battery can cause a lot of bewildering negative symptoms. I am not sure but I believe you should have heard power supply or fans engaging if battery was the reason. Have you tried keeping your ear against the mac?

He can log into iCloud icloud.com via a browser on any computer to have a look at what’s there.

“They” used to (don’t know if they still do) have small batteries on the motherboard to maintain PRAM (time, settings, etc). When those got too old, usually in a closet, they could burst and do serious damage to the motherboard (learned the hardway). Don’t know it that could be the case here.

Good luck.

I think figuring out which model it is would be helpful.

The serial number of the machine is probably (if I remember right for this age of machine?) on a label on the bottom of the foot. Given a serial number, you can look up the model: eg type it into the box at https://www.thebookyard.com.

One simple thing to try if possible, although unfortunately I think not very likely to solve the problem. Try a different power cable. In the UK at least, the mains plug on the end of this cable has a fuse inside, which might have blown. I can’t check without knowing the model, but I think the connector at the Mac end is probably an IEC C13 socket, and a common “kettle lead” should do the trick - no need for the exact Apple part.

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Apple has traditionally used a size 1/2-AA battery for maintaining PRAM settings. These batteries should be 3.6v lithium batteries. They shouldn’t leak over time, but they will eventually die and need replacement. Some Macs won’t power-on with a dead battery. Most Macs will have this battery in a socket (although some of the oldest Apple computers have it soldered to the board).

Alkaline batteries do leak when they get too old, and that leakage can cause damage. But I don’t think Apple has ever used alkaline batteries on their motherboards. This is very different from PC motherboards which often used alkaline or rechargeable NiCD/NiMH batteries - which do leak can cause damage when they get too old.

But batteries aren’t the only thing that can leak. Electrolytic capacitors can also leak, causing board damage. And capacitor replacement is much more difficult than battery replacement. Many Macs (especially from the era of the Quadra/Centris/Performa models) suffer from leaky capacitors and will need repair work in order to become fully functional again.

But capacitor replacement is definitely doable. And modern capacitors are much better quality than the ones made in the 90’s. So you can often replace those old electrolytics with ceramic capacitors, which won’t leak.

Needless to say, the specific procedure for capacitor replacement will depend on the specific computer. But if you’re curious, here’s a (long, mostly unedited) video showing one such procedure on a Centris 610 (1993):

The one that leaked wasn’t a Mac or Intel. Can’t remember the battery chemistry but same 1/2 AA.

Since I don’t think it’s been mentioned yet, definitely try Apple’s checklist for a Mac that won’t turn on.

Definitely. Assuming the 2009 date is approximately correct, this would be in the Intel Core 2 Duo era. Here’s iFixit’s page for the 20" 2009 model, which may be representative of what you can expect to find inside.

It would appear that by this time, Apple stopped using the 1/2-AA batteries and switched to using a BR-2032 lithium coin-cell PRAM battery. Here’s the guide to battery replacement. It doesn’t require a complete teardown, but you do have to remove the front bezel in order to expose that part of the motherboard. It doesn’t look too hard, but a time-consuming pain in the neck.

If you can make it power-on after resetting the SMC or some other similar procedures, you might try replacing that coin cell. If you’re willing to open the case enough to access that battery, then you may want to replace it anyway.

If we look through that model’s teardown. Like most motherboards, there are electrolytic capacitors on it and on the power supply board. They can leak, and if they do, that can prevent the system from working. But this board is might higher density than that old Centris 610 motherboard, so it may be more difficult.

Thanks for all the replies!

Just a few notes:

  • I did see that Apple doc on what to do in an iMac won’t start, but all it suggested was unplugging it (which it was) plugging it back in and holding the power button in for 10 seconds. That didn’t help.

  • There were no sounds at all - not the startup sound or fan sound or anything.

  • The power cable seems a very unlikely candidate. The outlet itself is ok - we tested it by connecting his printer to it.

  • While he does backup everything now in iCloud, I think he did not when he was using his computer. So his stuff isn’t all there. In particular, I think he’s interested in music he ripped from CDs. Would those go into iCloud anyway?

  • He had a Time Machine drive from which I recently successfully got old photos he wanted. But after that the Time Machine drive broke and no matter what I connect it to it causes that device to go into endless restart modes. That’s a shame because I have a spare MBP 2013 and created an account for him on it in anticipation of setting it up with all his iMac data. But now that’s gone.

  • I will try to get him to locate the model number or serial number. He’s really hard to explain things to.

Thanks all!

He was able to find the serial number on the bottom and I looked it up.

Pasted Graphic 3

It’s a 2008 iMac “Core 2 Duo” with 1 GB of RAM and a 320 GB #DerangedDonald.

Anything simple he can do to wake it up? I’m guess if he didn’t leave it unplugged for 6 months that PRAM battery or whatever it is wouldn’t have died.

Be very very careful if you do this. IFixit makes it look easier than it is unless you do it on a regular basis (which is my main beef with iFixit - you can get into trouble easily even when following their instructions to the letter).

Having owned this generation of iMac and disassembled it, there are cables attached to the LCD screen that are short and fragile. You don’t have a lot of clearance to lift up the screen to get access to the motherboard - unless you take the next steps of detaching those very fragile cables.

I absolutely don’t intend to do it. :slight_smile: If my friend wants it fixed and it needs to be opened to be repaired I’m going to ask him to find a repair place to do it for him.

But I think at this point if it can’t be easily started up he’s just going to junk it.

Too bad about the internal battery though.

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If he wants the files from it, you can still open it up and recover the drive, then put that it an enclosure or use a cable to mount it on another mac to copy them, then ether destroy the drive or wipe it (New drives are cheap, and that one is old enough to not keep). Opening a box is a -lot- easier than opening it in such a way that you can put it back together again, and cheaper for a repair shop. And a repair shop might have a use for any still good parts, or be willing to take enough care to get the whole mac working again for resale, which might lower the price a bit more.

It’s worth recovering the drive unless it has filevault 2 with a good password. If you just toss/recycle the machine, some random person might recover the drive and gather anything of interest.


That’s an excellent point. I assume opening it with the intention of not putting it back together and just grabbing the drive and putting it in an enclosure is not so difficult?

Thanks. The “EMC 2134” was enough to locate the specific iFixit page for this model.

Although they don’t have a PRAM battery replacement guide for this model, I see from this picture:

That the PRAM battery is still in the lower-right corner. So removing the front bezel is enough to access it. No need to remove the display for this specific procedure.

I completely agree, but I’d also point out that this specific procedure (replacing the PRAM battery) involves only removing the front bezel, not the display itself. There is a wire (the microphone cable) you need to disconnect, but it’s not as hard as other procedures (e.g. replacing the HDD) that require removing the LCD panel and all of its cables.

Thanks for that info. I would still prefer to find a place which can do it. For one thing, sometimes batteries for something that old are themselves old and won’t work. So having a shop do it would be more reassuring. Having trouble finding a shop though.

Mactracker shows this model (A1225 etc) is “iMac (24-inch Early 2008)”.

I searched the web for [imac service manual 2008] and found the official Apple service manual (PDF).

The battery on this model is a CR2032 coin battery (page 54). But the only problem the manual describes related to this battery is nine beeps on startup (page 246).

The manual gives some steps to follow (page 211) for No Power (“The computer will not turn on. The display remains black and there are no sounds from the fans or drives.”). Worth a look.

The earlier steps there are things that your friend could try, perhaps: verify the power outlet, try a different power cord, reset the SMC (disconnect all cables from the machine for at least 15 seconds).

The next step is remove and reinsert (“reseat”) the RAM. This machine was designed for customers to be able to do this - use a screwdriver to open the access door on the bottom. See page 24. I appreciate this might not be a possibility for your friend, though.

The steps after that involve removing the front bezel and examining four diagnostic LEDs, which show (p203) the presence of power at various places within the machine and other indications. This might show that a new power supply board is required. (I’ve had to replace this board on my mid 2011 iMac, which had the same no power symptoms.)

I used to repair Apple machines of around this age. I thought the service manuals were fairly good. If you can convince your friend to do some of the above, or find a repair shop that can, perhaps you will be in luck.

Thank you. That’s very useful information! He would definitely not be able to do it himself, but maybe I’ll make another visit over to his place and try it. We did try the removing cables stuff. We didn’t try a different power cord, but there is another iMac (a few years newer) there which belonged to his late partner who passed away in 2020, and I think it’s the same. However, when we tried to turn on that iMac it also didn’t work.

Interesting, since iFixit found (on the model one year later) a BR2032. The two are the same size and have the same nominal voltage so are mostly interchangeable for low-power applications (like maintaining PRAM memory).

CR2032 provide more power and last longer for higher-power applications, but the voltage varies more between its new and “dead” states. BR2032 provide more stable voltage (less variation) and may last longer for low-power applications.

I wonder if Apple changed its mind about this at some point, or if they think it doesn’t matter too much.

See https://electronicshacks.com/br2032-vs-cr2032-batteries/

If you do manage to remove the hard drive this adaptor might be useful for attempting to read it with another computer. This is instead of a hard drive enclosure.

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Thanks. Looks useful.