Hi Halliday (Bullard)"),
Thank you for confirming. I'll move the thread under Surface Pro 7 since it seems that the device is a Surface Pro 7 based on the released date. For the issue on the power supply, please try to follow these steps below first to troubleshoot:
1: Disconnect PSU and check its connection
Unplug the power connector from side of device
Unplug the PSU from the wall outlet
Check that the power cord is securely attached to the PSU
Unplug any USB devices from the charge port on the PSU
Wipe the pins on the power connector with a soft, dry, lint-free cloth (microfiber cloths work great).
Plug the PSU back into the wall outlet. If possible, try a different wall outlet
Plug the power connector back into side of device
Verify that all connections are secured
2: Check for any physical damage
Check the PSU for any physical damage on its connectors, brick and cables
3: Change the orientation of the power connector
Try turning the connector that attaches to the side of the Surface and plug it on a different position
If the issue persist, I suggest contacting support for assistance as what StevenK_M suggested.