[MoonRiver]

I have an old iMac. Recently it started crashing several times a day. I also started having trouble with the USB mouse. It goes inactive and I have to unplug it and plug it back in to get it to work. There is not a one-to-one correlation between the mouse failing and the computer crashing., but both are new events.

Yesterday, I moved the mouse to a USB port on a multiport usb and the mouse has worked fine since then and the computer hasn't crashed.

I ran diagnostics on the hard drive and it is OK, same with memory. Could it be as simple as a bad usb?

 

[Nevada]

While I don't pretend to know much about Mac's, if it's working fine I would leave it alone.

That said, it sounds like a bad mouse.

 

[backwoodsman7]

Could it be as simple as a bad usb?

It's possible. If Macs do it the same way as PCs, the different groups of USB ports are run by different USB controllers. So when one of those dies, it affects all the USB ports it runs. You could test to see what ports work fine, and what ports have the problem. If it's consistent, you probably have a failing USB controller.

 

[MoonRiver]

It's possible. If Macs do it the same way as PCs, the different groups of USB ports are run by different USB controllers. So when one of those dies, it affects all the USB ports it runs. You could test to see what ports work fine, and what ports have the problem. If it's consistent, you probably have a failing USB controller.

There are 4 USB ports on the computer. One is used by a printer and I haven't had any problems with it. One connects to my USB hub and no problems. The other I use for recharging my watch so it isn't used that often but no problem with it.

I moved the mouse from the USB that may be bad to a port on the hub and so far, so good.

This is a 2009 IMac, but for what I use it for it works fine. Maxed out on memory and I can't upgrade to the latest OS version.

 

[SWTXRancher_1975]

You’re just taking shots in the dark until you take a look at the crash dumps. https://apple.stackexchange.com/questions/26480/where-can-i-find-my-crash-logs

 

[MoonRiver]

At least 30 hours since the last crash, so I think the usb port is the problem.

 

[MoonRiver]

You’re just taking shots in the dark until you take a look at the crash dumps. https://apple.stackexchange.com/questions/26480/where-can-i-find-my-crash-logs

Dumps are what I go to as a very last resort. At least 90% of the time, the problem can be identified by what the user, me in this case, was doing at the time of or near the time of the crash. Or by identifying something that was changed.

 

[SWTXRancher_1975]

Dumps are what I go to as a very last resort. At least 90% of the time, the problem can be identified by what the user, me in this case, was doing at the time of or near the time of the crash. Or by identifying something that was changed.

it’s certainly not outside the realm of possibility that it’s the port or the mouse.

there’s a lot of ways a USB port can fail. Some of the most common come from physical degradation of the port over time. They’re only built to withstand so many plug/unplugs and if it’s a wired mouse stress from the wire on the port could be a factor. I’ve seen “jiggly” USB ports cause a system to short and hard power off with no warning more than once. Of course the chipset could also have an issue on that port, or there could be a driver issue. It’s just an unverified assumption not that there’s anything wrong with that on something like a Home computer. If the issue stops when you stop using that port then you’ve got a workaround.

 

[MoonRiver]

It's been over 2 weeks since I moved the mouse to a different port and not a single problem since then. No crashes or lockups.