Some Zebra Printers have a sleep mode which might need to be disabled.  You can do a google search for this.

For your code, technically you could just put this (as the rest is default):
DoCmd.OpenReport "Maintenance_Label"

-Raymond

Thanks Raymond I'll try that

Yeah, I usually disable any power saving modes while my laptops are plugged in. You're only saving a fraction of the power they normally use by keeping those ports awake. While they might save you some battery life if you're traveling and you're on battery, if the laptop's going to be plugged in, go into performance mode, turn all that stuff off.

Had it like that it's just the odd time I can't be bothered to connect the power supply, it goes to sleep while I'm doing something else and wondered if there was something I could reset without having to shut access down and restart. If not I'll just keep the power supply connected and have the timer turn the screen off.

Yeah, that's pretty much what I do. I have multiple laptops in my office. I got rid of desktop PCs years ago. Everything I have is a laptop. And I just leave them running all the time. Sometimes I'll close the lid, but I have the lid action set to not do anything except turn the screen off. They don't use that much power, so you're fine. And modern computers are designed to be left running 24/7. As long as they have proper ventilation, you're fine. And if you set them to high performance mode and make sure the USB ports are set not to go to sleep, you'll be in good shape.