My display fails to come back on after waking my Mac

when I wake my computer from sleep, I have to unplug my 27” Apple cinema display ''and plug it back in several times to get to come on. Today, my little workaround failed to work and I’m wondering if it the power supply or perhaps something else. I haven’t had any other issues with the display other than this minor inconvenience. It’s an old display, but I’d really like to revive it if possible. Any ideas on what’s going on.