I do not have enough information to say. This is just a guess.
MAYBE:
It looks like a error amplifier at pins 43/44.
The supply is looking at 12V and 5V for DC and also looking at 3.3V for ripple.
These supplies were never designed to run with 5V unloaded!
There is a voltage divider: R60 & R62 pulls up. R40 & R39 pulls down.
If you want to increase the output voltage by 10% try decreasing R40 by 10%. (put a 730k across R40)
The idea is to pull down on pin 44 a very small amount more so the supply will increase the output voltages slightly.
You probability can not get more than 15% more voltage before you hit a limit.
Good Luck