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Shawn
Shawn, Computer Engineer
Category: Mac
Satisfied Customers: 275
Experience:  15 years of Mac software and hardware troubleshooting experience, 10 years of programming experience
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I have an older I-Mac, the one with base that looks like a

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I have an older I-Mac, the one with base that looks like a Hershey's kiss. This week, the USB bus started cycling. About 20 secs on and then 20 to 30 secs off. When it does this, of course, I lose mouse control and have to wait for it to come back up. I've never heard of this problem before. Have you?
Thanks,
XXXXX XXXXX
Hi Jack,

My guess is it's probably a hardware problem. I've worked with a handful of computers like yours before and they're all starting to go bad.

Something easy you can try: if you have (or can borrow) another USB keyboard and mouse, try using those on the computer and see if the connection still cycles. It may just be a bad keyboard or mouse cable.

Also, try unplugging any other USB devices that you have connected to the bus, leaving just the keyboard and mouse connected. If another device (e.g., printer, scanner, external hard drive) is malfunctioning then it could be shorting out the USB and causing the problem you're seeing.


Let me know how these ideas work for you. If they don't, we can try some software fixes before labeling it a hardware issue.


Kind regards,

Shawn

Customer: replied 8 years ago.
I had already tried two other mice, another wireless and a wire variety with no change. Unplugging all USB, a hard drive and a printer seemed to change the cycle time so there is more on than off, but it still shuts off.
Hi Jack,

Have you tried a different keyboard? That could be the issue as well.


If another keyboard doesn't solve the problem, you can try some basic troubleshooting:

1) Boot in Safe Mode and reboot
http://support.apple.com/kb/HT1455

2) Repair permissions
https://kb.iu.edu/data/aoxn.html

3) Reset the PRAM
http://support.apple.com/kb/HT1379

4) (last resort) Reinstall a fresh copy of the OS using the ARCHIVE AND INSTALL option. This will not erase your files, it will just reinstall the operating system.
http://support.apple.com/kb/HT1710


If those don't work, then it's a hardware problem and you should consider whether it's time to get a new computer. Repairs for machines of that age are pretty costly.


I hope this helps! Let me know if you have any more questions. Kind regards,

Shawn
Customer: replied 8 years ago.
I booted in safe mode and reset the PRAM. The mouse now seems to be working. What does safe mode do? Will this be a permanent fix, or do I have to do it repeatedly?
Jack,

Great! Safe mode runs some software-level repairs on the computer, and may need to be run again from time to time to keep things running smoothly. This is normal, and is nothing to worry about. If it fixed it, then you should be good to go! (It's kind of like preventative maintenance on your car).

I would also recommend doing the Repair Permissions step that I mentioned, as that will clean up other things that may be lurking waiting to cause problems in the software.


Let me know if you have any more questions! Kind regards,

Shawn

Customer: replied 8 years ago.
You missed my add-on reply. It quit working again. That's why it takes so long to reply. I have to wait on it. I just ran the disk permissions fix. It still hangs up about every 15 to 20 secs. I'm going to try the safe boot again. It seemed to fix things for a short while. Maybe the combination of permissions fix and then safe boot will make a difference. I can tell you that this IMac that I replaced my Power PC with is a piece of junk. I wish I had the old one back.
Hi Jack,

Aaahhh - that message never came through for some reason. Yeah... it doesn't sound good then. You might try the archive and install fix, or you can take it to an Apple store where they can try to fix it. My gut tells me hardware. You're right - those particular iMacs were not built well (I have a junk one sitting in my attic now that has hardware issues).


Let me know if there's anything else I can do to help. Kind regards,

Shawn
Shawn and other Mac Specialists are ready to help you
Customer: replied 8 years ago.
Shawn,
I have to agree that it is hardware. With everything unplugged and doing the software fixes, it's getting worse with more off time than on. Thanks for trying.
Jack
Jack,

I'm sorry to hear that it's not working out for you. The Apple Store might be able to fix the hardware if you choose to go down that path, but I'd consider whether or not it's time to get a new computer.


Thanks for using JustAnswer!

Shawn
Customer: replied 8 years ago.
Shawn,
I have a 20" laptop coming. It's big enough that I'll use it on the desk and still be able to haul it around.
Jack
Jack,

Awesome, congratulations! I hope you enjoy your new laptop. :-)


Best,

Shawn

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