Hard Drive Apple iMac G5 Repair Story

When an Apple iMac G5 locks up on you, it might mean the hard drive is bad.

Many folks have contacted me over the years about their Apple iMac G5 problems they have been having because of bad motherboards or power supplies. Well, I thought I would share a story of my own, in regards to trouble shooting a bad iMac G5, in the hopes that it might help some of the folks out there in Apple iMac Computer land.

I recently picked up a used iMac that was giving the previous owner fits, in that it would eventually, after some time of being turned on, would lock up on them and only show the Apple logo at startup with the little circle going round and round. The fans would start turning at full speed. Once this occurred, the only way to get it back up and running was a fresh load of the software from the DVD disk back on to the hard drive.

Prior to loading the software back on the hard drive, I had gone through the procedure of checking out the capacitors on both the motherboard and the power supply unit, but did not see any signs of capacitor trauma, as in; bulging, leaking, or blown capacitor bodies. When having an iMac G5, it is always wise to begin with a visual inspection of both the motherboard and the PSU. Refer to my write-ups on repairing the Apple iMac G5 motherboard and how to repair an iMac G5 power supply unit for complete details.

I tried resetting the PRAM (Parameter RAM) and also tried resetting the SMC/PMU [System Management Controller (Intel Macs) or Power Management Unit (PowerPC Macs)]. I also tried replacing the PRAM backup battery (Energizer 2032) that retains the small amount of nonvolatile RAM (NVRAM) for the PRAM. This is where the date and computer settings are stored when the computer is turned off. None of this made any difference on my iMac lockup problem. Here is a very good article overview of the PRAM and SMC/PMU failure symptoms and when to reset the PRAM and SMC/PMU.

Well, after repeated hardware tests, with no indications that any hardware was bad (so much for hardware tests), I pulled out the old Maxtor 250 GB hard drive and tried reformatting it externally and backing up one of my other iMacs to this hard drive using a USB connection and an external hard drive adapter. The backup was completed successfully, and I returned the hard drive into the original iMac G5 cassis, and it booted up. Well, this was only a short term success. The iMac locked up when trying to do a software update. I was thinking that the software might be locking up because it was installed on the other iMac and registered on the other iMac. So, once again I took a brand new Leopard software disk family pack, and tried loading it on the hard drive again. No luck on this software load either. It bombed out part way through the loading process and returned to the Apple logo going round and round on startup.

Well, I am not one to let a little Apple logo roadblock stop me from getting to my iMac computer land destination. So out I go to my local Frys store (Frys is a large electronics store on the West Coast and another 8 states) to find out the best deal on a serial ATA hard drive. I didn’t want to spend a fortune, and I wanted to get the best value for the money. I ended up purchasing a Hitachi 640 GB HD for around 70 dollars. I figured I could always use this drive on something else if it didn’t work to fix the problem on this iMac.

So, I brought it home, opened it up, placed the mounting brackets on the new hard drive, mounted it in the iMac, and buttoned the whole computer back up. I then placed the Mac OS X Leopard DVD install disk in the slot, turned it on, held down the “C” key on startup. I then used the disk utility to format and mount the hard drive. Then loaded a fresh installation of OS X Leopard, did the updates, and have been running terrific for three weeks or so with no problems. I even added a “matched set” of PC 3200 1GB memory sticks for a total of 2GB of RAM. Now, I am a bit jealous for my own original iMac G5 computer with Mac OS X Panther installed. I think I will upgrade my other 20 inch iMac G5 to Leopard too. But that is a project for another day, and I am told that you have to do a fresh install too. Which means backing up and transferring the files over to the new installation.

Well, for the time being I am on happy trails to you, until we meet again.

Update to article: 12/25/2010

Just last week, I had another iMac G5 computer with a Seagate Barracuda 7200.7 160 GB hard drive (Apple identification:  160GB C6SER 655-11109D “KA45304C7RT9A)   go out. I went to FRYs again and selected a 1TB Seagate drive (drive only, not boxed) and installed it. I had a problem that it would not show up with the Apple Disk Utility. However, when I used my adapter plug to plug it into a PC, the drive would display. I tried using the jumper to force it to a slower access speed, but it still would not show up in the iMac. I then took this one back and got another brand (Hitachi 500 GB hard drive only, not boxed) from Frys again, but this one was completely dead. It would not spin. It was an old drive that was the last one in stock. I took that one back also, and Frys confirmed that the drive was indeed dead.

However, I did find another Hitachi 660 GB SATA hard drive online at Frys that I did order. When that one came in, it plugged in just fine and showed up with Disk Utility, formatted, and loaded software with no problems.

I believe other manufactured brands internal drives will indeed work with the iMac G5s, I just have not been able to confirm which ones.

Jim Warholic

Apple iMac G5 Take Apart Procedure 1st and 2nd Generation

Here is the procedure that I used to replace the capacitors on the Apple iMac G5 MOB.

Here is the link location of the Apple service manuals, with step-by-step instructions in PDF document form for removal and replacing everything on iMac G5 computers and other Apple products including: Cinema Displays, MacMinis, Laptops, eMacs, iPods, iMacs, and Towers. (link opens in new window)

When you take it apart, start with this order:

  1. Lay the iMac face down on a soft, protected surface.
  2. Back cover removal. (Loosen the three screws on the bottom lower edge, then lift up carefully from the bottom up).
  3. Take close up pictures of your G5 mother board and inside the iMac for your reference in case you need to refer to something for proper installation.
  4. Power supply removal ( http://manuals.info.apple.com/en/imacg5_17inch_Power_Supply.pdf ).
  5. Verify Power Supply capacitors are not bulging or blown out.
  6. Hard drive removal.
  7. CD removal.
  8. Memory cards removal.
  9. Right fan cover removal.
  10. Lower left two small plug connectors undo by carefully taking needle-nose pliers and tug the plugs upwards to disconnect them.
  11. Fan plugs – disconnect.
  12. Airport option removal, being careful not to break the very delicate antenna wire clip. You might want to leave the wire attached and just move the Airport out of the way.
  13. Then remove the Torx mounting screws. See the special 12-in-1 screwdriver with Torx and Phillips bits.
  14. Carefully lift out the MOB, making sure all the mounting screws were removed. Do not force it.
  15. Heat up the soldering iron, with a wide tip attached, and working from the bottom and the top of the MOB, with the MOB tilted up on edge, heat up one leg of a capacitor on the backside and rock the capacitor slightly from the top. Then do the other leg, and the cap will come out of the hole.
  16. Remove all capacitors in the groups.
  17. Once the holes are clear, (pins work well), then place the high quality low ESR capacitors in the holes, making sure the positive and negative legs of the capacitors are properly situated in the holes. Do not install caps backwards. Major damage will most likely result.
  18. Apply Arctic Silver thermal paste heat sink compound to the small area (make sure it is cleaned with isopropyl alcohol), on the bottom of CPU. Cover it and the matching heat sink area with a thin layer (not to excess). Use a small razor blade as a scraper to remove the excess. Keep it thin, thin, and thin.
  19. Reassemble the motherboard, (don’t forget the white light tube that displays the “power on” light on the front cover of the iMac), hard drive, DVD/CD Super drive, cables, plugs, fan covers, memory modules, and make sure you don’t have any extra screws left over.
  20. Double check and triple check your work.
  21. Place the back cover on.
  22. Plug everything back in and turn it on.

Important Notes:

  • Don’t forget to put new heatsink compound back on the bottom of the processor chip, which is located on the bottom of the MOB, and the solid plate heatsink assembly located on the chassis: Arctic Silver. Several heating up and cooling down cycles is required for maximum thermal heatsinking effectiveness.
  • At least a 60 watt soldering iron is recommended and a good solder sucker and some plastic headed sewing pins for heating up and push removing solder from holes. Read the article: Soldering Tips for Lead-Free Solder for more detailed information.
  • Use rosin core solder only. Do not use acid core or acid flux. Use lead free, or, in my opinion even standard 60/40 leaded solder will work (although there are few lead-free caveats) for soldering the new caps. Just make sure there are no cold solder joints.
  • How to Tip: Use a few small pins to clear the holes when the soldering iron is used to heat up the holes to remove the old solder.
  • Don’t try to bypass this advice. Highly recommend replacing all the caps in both groups. Even though one or two caps might be visibly bad, the others are more than likely weak or on their way out too.
  • It’s up to you if you want to attempt the repair. It depends on how comfortable you feel about doing it yourself. The degree of difficulty on MOB caps replacement on a scale of 1 to 10, with 1 being the easiest and 10 being the hardest; a 7.
  • Double check your power supply unit. Open the PSU to check those capacitors too.
  • Degree of difficulty on PSU caps replacement on a scale of 1 to 10; a 3.

The procedure above is going off of memory.


  • Layout your screws as you go.
  • Have lots of room to lay it out.

Refer to my articles, read carefully, and suggest printing them out for reference.

iMac G5 Motherboard repairs procedure
iMac G5 power supply repairs

Feel free to contact me if you have any further questions.


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When it comes to fixing your Apple iMac G5, I’ve got the repair solutions for you.

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Find Apple iMac G5 capacitor kits for mother boards and power supplies available to purchase online. Arctic Silver Thermal Heatsink Compound and computer tools are available too. Apple iMac G5 extra long life (10,000 hours) low ESR Caps.

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I’m adding new items for sale on a regular basis at J West Sales eCommerce Store, so check back with me later. In the mean time, if you are looking for something special, or would like to see me carry some other products for sale, let me know, and I’ll see if I can track them down for you. Contact Jim Warholic today.

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