My external keyboard does not have a suspend button. Is there a way I can set up Ubuntu to use a different key (or any key for that matter) to wake the PC if it has been suspended?
If you run the following command, you will see a list of USB devices and if they are enabled to wake up the system.
You will see a list of items such as the the one seen below.
USB0 S3 *disabled pci:0000:00:12.0
Once you have established which device is the keyboard, let’s say USB0, run this command.
sudo su echo USB0 > /proc/acpi/wakeup
Now, if you run the command from the start again, you should see enabled next to the device.
USB0 S3 *enabled pci:0000:00:12.0
That worked for me, and I can wake up my desktop with any key.