possible power problem

my MVS CAb is acting up.
Sometimes when i start it the coin lights go real dim and the monitor doesn't come on. then when i shut it off the speakers make a strange farting (heheh) sound. do i need to get a new power supply or is something busted in the the cab (lights, monitor drawing too much power, speakers drawing too much power)?

please help

sounds like the psu, get a test meter and check the 5 & 12 volts.
Probably a 12 volt issue

forgive my newbie ignorance but what is a is PSU?

and if it is a 12v issue what should I do?

thanx

power supply unit, if the voltages are low it would be as well to replace the power supply.