USB Ports on back of Imac desktop stopped working.

Reset the NVRAM, as per > Reset NVRAM or PRAM on your Mac - Apple Support

1. Restart while holding the Option, Command, P, and R keys for at least 20 seconds.
2. Then release the keys and let the iMac startup normally.

Reset the SMC, as per > How to reset the System Management Controller (SMC) on your Mac - Apple Support

1. Choose Apple menu > Shut Down and wait for your Mac to shut down.
2. Unplug the power cord.
3. Wait 15 seconds.
4. Plug the power cord back in.
5. Wait 5 seconds, then press the power button again to turn on your Mac.

note: Wait 60+ seconds instead of 15 seconds in step #3.

Then if the USB ports are still not working, you will need to make a Service appointment at your local Apple Store or Apple Authorized Service Provider. see > https://locate.apple.com/

joyousnoel7 wrote:

Thanks for the quick reply. I tried all the steps you had laid out. So far no luck. Looks like I will need to take it in for repair.

Sorry to hear that.

With that said, it is asking for the serial number. When I submit it, it comes up as invalid. I copied and pasted the serial

number exactly as shown under "About Mac". This is keeping me from going forward with the help process.

Did you buy it new or used, from whom and how long ago?

Your other option is to call your local Apple Store or Apple Authorized Service Provider and schedule an appointment. If you or the previous owner never registered it, then you also should bring a proof of purchase receipt.

joyousnoel7 wrote:

also when I do the apple boot up, everything comes up exactly the same as if I never shut the computer.

There is a "Reopen" check box on the shutdown, restart and log out window. If it is checked, then the Mac will resume where it left off when you startup, restart or log in.