HDMI No Input Signal from Macbook pro to external monitor - PLEASE HELP

I've been using my Acer external monitor with my Macbook pro for 2 years when my screen flickered and suddenly stopped working. Message on the screen is no input signal. My laptop thinks it is connected and I can move my mouse to the external monitor but there is no image.

I've tried my roommates mac with my monitor set up and it works perfectly. So clearly an issue with my computer.

• I've reset, rebooted, rebooted in safe mode, updated, turned everything on and off, changed resolutions, tried different cables - nothing works so far

Please help.