In case anyone else finds this interesting or helpful, here's an overview of how I installed a new PSU (from Centurion) into my Mega ST4. I tried to keep the soldering and other connections as pretty and clean as possible, but I'm a novice at that stuff so go easy, LOL.
One thing I want to call out is that although Centurion boasts about their STPSU r2022 being completely plug and play with no extra work, that isn't always the case. The white and black wires on the Mega ST connections were too short to reach the new PSU connectors, so I had to cut old ones off, clean it up, and install new 18 AWG 600V wires. I had the exact same experience with my STe when I replaced the PSU a couple years ago (using a Centurion PSU). I'd still buy the Centurion PSU again if I ever needed one, but just wish they would either relocate the connectors to be closer to the original wires, or mention that you'll probably need to solder on new wires when installing.
FULL VIEW WITH OLD PSU:
CLOSE-UP OF OLD PSU:
WIRES TOO SHORT TO REACH NEW PSU:
NEW PSU CONNECTED WITH NEW WIRES; FAN ALSO CONNECTED TO NEW PSU BOARD:
JUST A DIFFERENT VIEW OF THE NEW PSU CONNECTED:
FULL VIEW WITH NEW PSU INSTALLED:
Good to know... thank you. I actually have two of these PSU's on back order that should be shipping this week so this was helpful.