My monitor died at 9pm on a Sunday and a $6 part from the hardware store saved me
Last Sunday my second monitor just went black while I was in the middle of a project, no warning, no flicker, nothing. I checked the power brick and it was warm but the little green light was off, so I figured the brick was toast. A replacement from the brand would have been $40 plus shipping and a week of waiting, and I was not about to do that. I grabbed my multimeter (the $12 one from Harbor Freight, nothing fancy) and tested the barrel plug, and sure enough I was getting 19 volts right at the tip, so the brick was fine. Turns out the issue was the DC jack inside the monitor had a cracked solder joint from years of the cord getting yanked sideways. I took the back cover off, found the two broken pins, and reflowed them with a $6 soldering iron I already owned plus a little rosin core solder. Total repair time was about 25 minutes and the monitor has been running fine for four days straight now. If you have a monitor that cuts out when you wiggle the power cord, crack it open before you buy a new one, and let me know if you have a better trick for reinforcing those jacks so this does not happen again.
a cracked solder joint from years of the cord getting yanked sideways" is exactly the problem, so the real fix is a strain relief loop or a zip tie inside the shell so the cord can't pull on the jack anymore. Even better, swap in a right angle barrel adapter so the cable hangs down instead of sticking straight out and getting bumped.