Old Cinema HD Display power adapters (for 30” monitor) keep going bad

This is a question for old timers who’ve been troubleshooting Macs 10+ years. I have to explain the details of the problem before I can get to my question. Hang in there…

I’ve got an old MacPro running an old OS, to continue using some obsolete legacy apps, and the monitor is the only problem I’ve had keeping the system going. When I bought it new, the 30" Cinema Display was supposedly one of Apples best, and cost over $2000, so I’ve hung on to it and tried to keep it going, despite the awkward adapter system Apple foists upon its users. I also have a newer iMac and a MacBookPro for regular tasks.

For no apparent reason, the Cinema Display monitor begins to intermittently go completely black while I’m working, while I’m doing nothing more than typing or moving the mouse. If I wait a few long minutes, it will flicker back on again, but eventually go black again. At first I’d restart the MacPro, which often helped. Then it didn’t help.

I found its the oval/racetrack-shaped plug connection in the adapter brick (Apple HD Display 150W Power Adapter A1098, connects to the MacPro) that’s apparently causing problems. Unplugging it and replugging it fixes the issue temporarily. Weirdly, the monitor comes back on dimmed, and the keyboard brightness buttons don’t work. It can only be brought back to normal brightness but holding in the button on the right side of the monitor.

But invariably, after some time, it goes black again. As time goes by, I have to do this 3, 4, 5 times a day. Eventually month after month of unplugging & replugging this connection apparently causes even more problems and eventually won’t get the monitor going again. And pressing the brightness button on the side of the monitor is becoming more and more difficult - it doesn’t work unless I really jam my finger into it. 

Apple stopped making these adapters long ago. I found the only solution is to search the net and buy a used adapter brick - another $75 each time. Heres one of these adapters for sale on eBay

After I’ve given up on an adapter, I found I can really jam the cord into the plug and the monitor will come back on, but there’s no way to hold it in that position. This leads me to believe the monitor itself is still perfectly good, and just this annoying adapter plug is the only problem.

Has anyone dealt with this kind of intermittent monitor adapter problem and had success overcoming it?

At this stage - 4 different add’l adapters bought and gone bad - I’m close to calling it quits for this monitor and simply throwing it out, which is a shame because its apparently not the monitor itself. 

Any solutions come to mind? I tried cleaning/shining the male and female connectors. nada

Whats the chance one of these bricks could be hardwired to the cable? i.e. strip the plug off the wire from the MacPro, open up the adapter brick and pull out the plug, then strip and twist the correct wires together?

I might be able to provide more info if needed. As of now, I can connect to the MacPro remotely but only get folder view. I don’t know how to share its screen, Get Info from any file, or open its System Profiler to get model or system numbers…

[Edited by Moderator]