iMac keyboard & Mouse.

[hoody]

Hi again all,
I really didn't think I'd be back so soon with another problem. The iMac is a late 2012, 21.5" and has a 1Tb SSD and upgraded ram, fitted by me. It's been performing perfectly well up until now with an apple wired keyboard and a Logitech wired mouse.
I hadn't shut it down and when I went to it this morning I pressed the space bar and nothing happened. I gave the power button a quick press and it woke up but neither the mouse or the keyboard would work. I dug out the apple magic mouse and it connected OK and worked, but I still can't get the keyboard to work, so I can't log in to my account. I opened the guest account but going through that, I can't find anything wrong. I gave the apple bluetooth keyboard to my son, so I can't try that. Any ideas what I can do other than buy another apple bluetooth keyboard?

 

[Raz0rEdge]

Did you get any messages when you started up again? If the Mac was asleep but needed the power button to come back up, it's possible the machine crashed.

Are you saying that you an login to the guest account and not your actual account?

There's just too many things here that you haven't explained for us to help you.

 

[hoody]

No messages at all. I didn't need to log in to the guest account as there's no password with it, but the keyboard still wouldn't work. I've re started it several times , but, only the magic mouse works.

 

[chscag]

If an Apple wired keyboard didn't work there may be a problem with USB. Whenever you open up one of those sealed iMacs there's always a chance of damaging cables. Especially the 21.5" model because it has to be disassembled to get at the memory slots.

You might want to open it up again and see if anything came loose or any cables may have been damaged. Or, you can try a BT keyboard if you can find one to use.

 

[hoody]

It must be about 9 months or more since I worked on it and being a desktop, it doesn't get moved around. I'll plug something in to the usb ports and see if it works OK. Later on since I started this reply: In the guest account I went to Disc utility and clicked on first aid for the SSD. It's working now and will be for some time by the look of it. I'll get back when it's finished, hopefully with some good news.

 

[Raz0rEdge]

OK, it helps to provide all the information. And I agree with Charlie, the wired keyboard has almost no reason not to work unless the USB port is busted. Since the wired mouse is working, you've got a working USB port, so just swap the keyboard and mouse and see if the keyboard now works and the mouse fails.

If two devices don't work with a given USB port, then that's the culprit.

Your iMac should have 4 USB ports, so try another one and if the keyboard works, make note of the failed USB port and avoid using it.

If in the future you need to plug in another USB device with 3 of the 4 ports are occupied, you will need to get an external USB hub and use that.

 

[hoody]

Ashwin, I'm using a magic mouse so not connected to a usb port. I took out the TM usb and put in the wired keyboard and it still didn't work. What comes to mind is that the keyboard and the mouse both failed at the same time, but this seems highly unlikely to me, although stranger things have happened. Neighbours across the road have an iMac with an apple wired keyboard, I'll ask to borrow that to try it out and let you know how I get on.

 

[Raz0rEdge]

OK, if changing the USB port doesn't make the USB keyboard work, but that port was working for TM then you might be right that the keyboard might have given up the ghost.

The only thing I can think of is a electrical surge, but that should've broken the USB port too. Very curious.

 

[hoody]

It gets curiouser, I know it's not a word... Anyway, I plugged the keyboard in to the hub and then into the usb port where the CCC backup was and then plugged the CCC usb in to the hub. Now it's working again. Later when I have time to play around, I'll shut it down and plug the hub in to one of the ports that didn't seem to be working. I'll let you know what happens. Thanks for your help.

 

[hoody]

I'm getting even more confused now. Yesterday I tried plugging the keyboard in to my macbook air and it worked perfectly, so I plugged it back in to one of the ports that we thought might have stopped working and it worked! I left it to sleep (the computer) overnight and this morning... you've guessed by now, no keyboard. Tried it again in the macbook and it worked. Plugged it in to the usb hub which is in one of the ports that wouldn't work yesterday and it worked. If anyone has any clue about this would they let me know. I'd buy an apple bluetooth keyboard but They're A$179.00 here.

 

[Raz0rEdge]

Oh, have you tried doing a SMC/PRAM reset of your iMac to see if that kicks anything loose and makes the keyboard work reliably again?

 

[hoody]

Now the keyboard's working again I'll have a try with those reset's. Fingers crossed.

 

[hoody]

I reset the nvram, pram & smc. The keyboard is working OK, but the usb port nearest the headphone socket isn't working. The other three are so the keyboard is in the hub. Last question is, could I have overloaded that usb port by having the keyboard and mouse in there and sometimes using it with an card with photo's on it?

 

[chscag]

If a USB port is overloaded, the system will warn you first and then shut the port down. Usually that happens most often if you attempt to charge a device that draws too much current from the port. Some hubs especially the ones that are not powered by the mains, can overload a USB port if you attach too many devices to it.

Usually though, a SMC reset will bring the port back to life if it hasn't been permanently damaged.

 

[hoody]

Looks like it's permanently damaged then, but I didn't think a keyboard and mouse would do that unless of course one of them went faulty. If that was the case, I hope it was the mouse because I'm now using the magic mouse.

 

[chscag]

I've never seen a keyboard or mouse cause a USB port to shut down. Generally neither one draws enough current to cause that to happen.

An iPad, especially the larger variety or non powered hubs are usually the devices which will shut down a USB port. Also some external optical drives can cause an overload. Once the ports are overloaded and shut down, there's always a chance that some damage may have occurred. And from that time on, the port becomes fragile until it finally gives out.

 

[hoody]

The hub I use is a non powered one, so maybe that's the cause. I'll have a look for powered hubs.

 

[Slydude]

The hub I use is a non powered one, so maybe that's the cause. I'll have a look for powered hubs.

I use powered hubs exclusively now and haven't used a non-powered one in quite some time. If you tend to connect high-drain devices like hard drives I consider powered hubs a must.

 

[hoody]

I have two external drives connected for TM & CCC. One's a spinner the other an SSD. I wonder if this was the cause.

 

[Slydude]

I have two external drives connected for TM & CCC. One's a spinner, the other an SSD. I wonder if this was the cause.

That could well be the source of the problem. That's part of what prompted me to shift to powered hubs. I had one or two drives that seemed to drop out of sight more often than I liked when using non-powered hubs.

If I had to guess, I'd suggest the spinner as the most likely culprit.