This power supply output voltages is higher than it should be, what could be the cause
Standard voltage actual voltage
23V = 32V
12V = 18.5V
3V = 7 V
Next 3V = unstable 0.5 to 1.6 V
5 V = unstable 6.8V to 7V
Meter on dc range..?
Meter tests ok..?
unusual for any reading to go higher than normal (within tolerances)
Input voltage/frequency match input requirements..?
Board looks to have been pretty warm around the switcher ic and associated bits.
Look for details on the switcher (5L0365R) which should bring up a data sheet and a load of schematics.
Perhaps not exactly the same as your board but enough to get an idea of the layout.
I found a couple of videos but mostly Russian/Vietnamese so not much help but it does show it is a fairly common type of board.
Can you read the markings off the flat side of the component?
You will need to trace the resistors that form a potential divider for that IC. Watch the video above, you are looking for the equivalent to R204 and R205 connected in the same way to IC1 on your board.