Why is my digital monitor not remembering it's settings ?

I know it's important to say what brand monitor I have but I don't know ,
the game is far away. Went to this customers house to fix a silent scope 2
that had a washed out picture. Went into the back, took out the aux.
adjustment pcb that's attached with a cable, went to the front of the
cabinet, made some color adjustments and the picture looked perfect. Played
a quick game ,shut it off and on , looked ok and I left. Problem came back.
Now the game remembers all it's other settings,free play etc but not the
monitor adjustments. There are 4 buttons on this, up/down/select/menu ( not
sure of the last 2) .It adjusts like a computer monitor, you go in and it
has a menu like brightness,color,pincushion etc. I can say for sure there is
NOT a save and exit setting. This has me stumped, any ideas ?
Could it be because the game has been unplugged ?
The game is 2 hours away so I can't just go and check the brand monitor
otherwise I could be more helpful.
thanx
Ron