iMac shuts down when printing

[iMas70]

My iMac shuts down when I try to print. It doesn't happen all the time but it does it a lot. I have to manually restart the computer. The printer is a Brother MFC-L2740DW. It's set up to print wirelessly. I might try connecting the wire to see if it keeps doing it but it shouldn't happen either way.

 

[BrianBaughn]

Try printing while in a new User Account.

 

[chabig]

My iMac shuts down when I try to print. It doesn't happen all the time but it does it a lot. I have to manually restart the computer. The printer is a Brother MFC-L2740DW. It's set up to print wirelessly. I might try connecting the wire to see if it keeps doing it but it shouldn't happen either way.

What do you mean exactly by "have to manually restart the computer"? I know it sounds like a detailed question, but I am genuinely curious. What steps do you take to restart it?

 

[iMas70]

It doesn't restart on it's own. I have to reach around to push the button.

 

[chabig]

I've never heard of a computer shutting itself down like that. I thought you meant that it crashed and had to be restarted. Very weird.

 

[iMas70]

I figured out the problem. My iMac and Time Capsule are connected to an APC battery backup. The printer is plugged into a different outlet. The battery backup reboots every time the printer wakes up or is powered on. It doesn't make sense but that's what's happening. Any idea why?

The good thing is my iMac is fine!

 

[chabig]

Thanks for sharing that. What a strange problem. Perhaps your battery is worn out and needs to be replaced. Turning the printer on puts enough of a load on it that it can't supply the demanded current.

 

[iMas70]

Strange thing is, the printer is plugged into a difference power strip. I have two strips plugged into an outlet.

Strip one has -

The APC battery backup. My iMac and Apple Time Capsule are plugged into that.

A Samsung Soundbar

Strip two has -

TV, DirecTV box and printer.

I never had a problem with the other computer and printer set up like this. It started happening after I set up the new printer (Brother L2740). I'm wondering if it draws a little more power when it starts up. Just enough to reduce power to the other strip and restart the battery backup. I also think the battery might be worn out. It's supposed to keep things running and not shut off when there isn't any power.

 

[tiijay]

I am having exact same issue. iMac5K Catalina 10.15.6 OS, plugged into a CyberPower 1500PFCLCD UPS power supply which is plugged into one wall outlet.
Brother DCP L2540DW printer connected to Mac via USB and plugged into a surge strip which is plugged into a second wall outlet.
Every time a print is fired, Mac shuts down and requires a manual power button to press, printer completes the print and stays powered on.
This one is a total head scratcher, how USB accessory can kill a Mac like that.