2019 27" iMac, USB ports failing after opening memory door

[AirBear]

I almost never shut this iMac down, just put it in sleep mode. Probably haven't even rebooted it more than a few times since I bought it a couple months ago.

Yesterday I shut it down after received some new RAM in the mail, I was going to upgrade from 8 to 24GB. Shut the iMac down, pulled the plug, opened the memory door and had a "duh" moment when I realized I had ordered desktop ram, not laptop style like the iMac uses. Never put my hand inside the RAM area, just put the door back on, plugged in and started back up.

Found out my USB keyboard didn't work anymore, but the USB mouse was OK. The keyboard is from my 2012 Mac Mini so I figured it had died. Tried switching USB ports with no luck. Then I plugged it into my 10 port USB hub and it worked. A short time later my Logitech mouse starting acting up. I plugged it into my Thunderbolt 3 external drive enclosure which has 3 USB ports and now it works fine.

Short of taking this computer in for warranty repair any ideas? The 10 port USB hub is plugged into one of the 4 iMac USB ports so not all of them are dead/malfunctioning. Accessing USB via the Thunderbolt enclosure seems to work fine so I could use that as a workaround for now.

The RAM is going back to BestBuy, this time I paid extra and ordered from OWC to be sure I get the right type.

Thanks,

AirBear

 

[MacInWin]

Reset the SMC? How to reset the SMC of your Mac - Apple Support

 

[chscag]

Very strange indeed. The memory door has nothing to do with the operation of the USB ports. And I can't imagine an almost new iMac would suddenly come up with defective USB ports. Something definitely does not sound right especially since one of the ports is working.

Try removing everything from the iMac including the hub, do a PRAM reset and a SMC reset to see if that brings the ports back to life. If that doesn't work, your only other option is to have it repaired by Apple. I'm not sure how Apple will handle the repair but I suspect they will send a pre-paid box so you can pack the iMac and send it to them. That means you will be without the machine for about a week or more.

If there is an Apple Store nearby where you live and if they're open and accepting appointments, you might try that instead.

 

[usagora]

Very strange indeed. The memory door has nothing to do with the operation of the USB ports.

Unless there was static discharge that occurred when he had the RAM door open that flowed through to the logic board... I know he said he didn't put his hand inside the RAM area, but of course physical contact isn't necessary for discharge.

 

[AirBear]

I've got an Apple store in a mall about 25 minutes away, they're open 11am-7pm. I think I can make an appointment to take it in. But I'll try unplugging everything and doing the SMC reset since all it involves is turning off the iMac and pulling the power cord for 15 seconds, plugging back in, wait 5 seconds then power back up. I need to do more troubleshooting, try some USB drives and see if they show up or not. I think the 10 port hub is working, although the printer could be connecting via wireless. But this Mac keyboard is plugged into the hub and I'm typing so it must be connected.

The static electricity thing is iffy, it's warm and humid outside, not good conditions for static to form. The computer room is on a hardwood floor.

 

[chscag]

The static electricity thing is iffy, it's warm and humid outside, not good conditions for static to form. The computer room is on a hardwood floor.

I'm not saying static electricity is impossible but I agree that it's highly unlikely. I have owned 3 iMacs and have always installed memory without ever having a problem doing it. Anyway, if you have an Apple Store that's close by and can make an appointment, that would be the best thing to do if the SMC and PRAM reset do not work to bring back the ports.

My understanding is that they will greet you at the door and take the iMac inside for analysis and let you know by email or phone what the status is. They do not allow you to go inside and wait by the genius bar as before.

 

[krs]

Based on the first post, it's not really clear to me which USB ports on the iMac work and which ones don't.

The 2019 iMac has four USB ports, maybe if you number them 1 to 4 from left to right and check each one individually.

Don't know about this Mac specifically, but other Macs with 4 USB ports sharecontrollers between two of them, usually port 1 & 3 and 2 & 4, so if one of the controllers is not working, one would still have two ports that do work.
Not saying that is the problem, but it's something to be aware of.
If anyone has a schematic of this iMac, it's easy enough to see ifany USB ports are shared and if so, which ones.

You also mentioned that the USB keyboard did not work but the USB mouse did.
Again, which USB port did you plug those devices into? I usually plug the USB mouse into a USB port on the keyboard.

And if you look under System Report > Hardware > USB
You should get some hints on which USB ports work and which ones do not

...or actually run a hardware test.

 

[AirBear]

This is a strange one but I haven't done the reset yet. My Logitech G502 mouse has a "G" that lights up when it's plugged into a USB port. The keyboard is an Apple USB with numpad from my 2012 Mac Mini.

Numbering the USB posts from 1 to 4 with 1 being closet to the center of the iMac and 4 being nearest the right side. I had the keyboard plugged into USB#4 a minute ago and it did not work, went back and plugged into the 10 port USB hub and it works. That hub is plugged into USB#2. Plugged a 1TB drive to USB#4 and it showed up on the desktop but the G502 mouse died, it was plugged into USB#3. No "G" light. I went and got my identical G502 from an old computer and also plugged it into USB#3. Light came on and it works fine?? Maybe an issue with the mouse, but doubtful. I moved the keyboard from the hub to USB#1. Works fine.

So what I have now is:

USB#1: keyboard, works
USB#2: 10 port USB hub, works
USB#3: Logitech G502 mouse #2, works fine
USB#4: External USB 3.0 1TB Freeagent GoFlex external drive, I can open it and browse files.

So everything working, more or less right now. I'll attach a screencap of the USB system report. The "Blue Snowball" is a mic plugged into the 10 port hub. The "Firecuda Gaming Dock" is a Thunderbolt3 enclosure with USB and video ports, none of those are in use right now.

 

[krs]

So what I have now is:

USB#1: keyboard, works
USB#2: 10 port USB hub, works
USB#3: Logitech G502 mouse #2, works fine
USB#4: External USB 3.0 1TB Freeagent GoFlex external drive, I can open it and browse files.

To find out what is wrong, if anything, you need to go step-by-step.
Best is a to use the same USB device on each of the four ports with nothing connected to the other ports.
Start with your keyboard since that will be a USB 1 or USB 2 device. Can you check the code of the keyboard at the back and post it.
Plug the keyboard into each USB port in turn, if you need the mouse, plug the mouse into a USB port on the keyboard, then launch some text application and check each USB port in turn to see if it works or not.
That would check the USB 3.0 ports on the iMac with a USB 1.0/2.0 device

Then repeat the test of each USB port on the iMac with the USB 3.0 external drive to see if it works properly (move the keyboard to another USB port as required.

Put the 10-port USB hub aside for now.

Assuming that all USB ports on the iMac work with both USB 1/2 devices, ie keyboard and mouse, and USB 3.0 devices, ie the external drive, then you can take a look at the 10-port USB hub.
What is the model of the USB hub, is it powered or non-powered, is it USB 2.0 or USB 3.0?

I have a 4-port USB 3.0 non-powered hub that worked fine with El Capitan but not with Mojave; there are a lot of technical differences in USB hubs, the more expensive ones tend to work better than the cheap ones.
In general I would say do all the testing and evaluation directly with each iMac USB port and once that is all tested and working, then take a closer look at the hub.

PS: Hope there are not too many typos since this is a rather long post.
Bottom line so far - I don't see anything obviously wrong with any USB port on the iMac - you may also want to make sure that the USB connector are nice and snug when plugged in.

 

[AirBear]

Keyboard code is: CC23252007VDPQVAK

Good troubleshooting steps. I'm starting to wonder if it was the G502 #1 mouse since #2 worked fine in the same port #1 had just been plugged into. I'll play with it some more tomorrow night.

 

[krs]

Doesn't your keyboard have an Axxxx number?
Mine is an A1243

I just wanted to check if it's a USB 1 or USB 2 keyboard/keyboard hub, but that is not that important unless it turns out that some of the iMac USB ports don't work with the keyboard.

BTW - If it is the mouse, it could well just be the cable.
I use a Logitech MX510 and havereplaced the cable on it three times.

 

[usagora]

Doesn't your keyboard have an Axxxx number?
Mine is an A1243

He mentioned in the OP that it was a "USB keyboard," so I doubt it's an Apple (Axxxx) one unless it's quite old .
EDIT: Nevermind....I just noticed he called it a "Mac keyboard" in post 5. Now that I think of it, I think Apple did still sell wired keyboards for a long while even after introducing the wireless ones (apparently up through June 2017).

 

[AirBear]

I think the culprit is the Logitech G502 mouse #1. G502#2 is working fine. I just unplugged it and moved to the keyboard's USB port (which quite frankly I had forgotten was there!) and it still works fine. I plugged G502#1 into my Win10 gaming rig and initially it lit up but a few seconds later the light went out and no mouse control on that computer.

I moved the External USB Drive from USB#4 to #3 and it still mounts just fine. I don't think I need to do anymore troubleshooting (I hope). New memory arrives in 2 days so I'll have to shut down again to install.

 

[krs]

I plugged G502#1 into my Win10 gaming rig and initially it lit up but a few seconds later the light went out and no mouse control on that computer.

Wiggle the cable (at the point where it enters the mouse body) of the problem mouse and see if the light comes on momentarily. That would give you an indication if only the cable is the problem.

 

[macnicol]

Curious

FYI, I have the same 2019 iMac 27" and bought and installed Best Buy 16gb RAM with no issue. I too am using my Apple USB extended keyboard from my old 2009 iMac working fine. But I use the Bluetooth Magic Mouse2 that came with the 2019 iMac. Just curious why you do not use the Magic Mouse2?

 

[AirBear]

FYI, I have the same 2019 iMac 27" and bought and installed Best Buy 16gb RAM with no issue. I too am using my Apple USB extended keyboard from my old 2009 iMac working fine. But I use the Bluetooth Magic Mouse2 that came with the 2019 iMac. Just curious why you do not use the Magic Mouse2?

Just because I'm used to the Logitech. Used them on my Gaming rig and my gaming laptop. They have Mac software for controlling and assigning buttons and I use that. I keep meaning to try out the MM but haven't got around to it yet.

The new memory has arrived but I'm in the middle of converting totally to the dark side with a refurb iPhone8+ (256GB) and new Apple Series 5 Smartwatch. I don't want to risk Computer issues until I'm done with the switchover. They have an app to xfer files/data from Android to iPhone but is slow, after an hour I'm just at 32%.

 

[AirBear]

I installed the additional 16GB of RAM tonight, total 24GB now. But the same thing happened with the USB ports. Since the G502 mouse was plugged into the keyboard I lost both. Plugged the mouse directly into USB#4 and it worked, plugged the keyboard into the 10 port USB hub and it worked. Waited a minute and plugged the keyboard back into USB#1 and it now works. So it seems like the USB ports take a minute to wake up at least for this keyboard. Of course it's an old keyboard so that could be it.

I shut down or restart this iMac so rarely I hadn't noticed this issue before.

My conversion to the dark side is now complete. I successfully setup an iPhone 8+ and the Series 5 Smartwatch. Very easy, just time consuming to re-enter all my info in the apps. I was impressed how the app they have you put on the Android phone ports over all free apps that have Apple versions. I only had to install 3 or 4 apps plus putting in username/password in a number of apps. And the watch was super simple, 10 times easier than setting up my Samsung Galaxy Smartwatch with my Android Sony Phone.

 

[Lifeisabeach]

FYI, I have the same 2019 iMac 27" and bought and installed Best Buy 16gb RAM with no issue. I too am using my Apple USB extended keyboard from my old 2009 iMac working fine. But I use the Bluetooth Magic Mouse2 that came with the 2019 iMac. Just curious why you do not use the Magic Mouse2?

I can’t speak for AirBear, but I don’t use it either and I also have that same iMac. That Magic Mouse is too small for my hands, just for starters. I need larger mice to fit my palm comfortably and otherwise prefer 5+ button ones that I can program.

 

[jasongoldworthy]

now see I agree with what lifeisabeach has said about if you need a bigger mouse then ofcouse go with that,

but I like the apple MM2 I love the swiping on the mouse but it is each to there own not everyone uses the mouse and keyboard that came with the Mac,

I have a Magic Trackpad 2 and never use it but I have it lol

so its one of them things we all have different preferences on what we like,

but its odd that the keyboard is dropping out is maybe the mouse pulling too much power from the USB port ? while its connected to the keyboard in some way ?

 

[pm-r]

I need larger mice to fit my palm comfortably and otherwise prefer 5+ button ones that I can program.

I still like and prefer the Logitech M705 USB Wireless Mouse I have used for many years now.
Nice and smooth, nice larger size than many, batteries last for about three years and I hardly ever turn the mouse off, and eight Buttons you can customize with their software.

And they have even made some small refinements over the years, but still the same model and can often be found on sale for under $40.00cdn.

It works beautifully with a top quality glossy 3-M Mouse Pad.

Similar mouse pad:
3M Precise Mouse Pad
https://www.amazon.ca/dp/B0017D5Z40/




- Patrick
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