universal mustang top box power supply

[buckstop]

i have a universal mustang  slot work perfectly until shut down for a while. ive read  posts about code 62 and upper board issues. what i have found is a dead battery on the top box board what is the voltage and battery  for the upper board. i replaced it with a 3.6 volt battery is tis corrrect? i still have code 62 and cant reset. when the machine works the upper board leds are on. they do not come on now, i checked the upper 5v  power supply and the output is 4v .  ive read of bad power supplies on the mustang machine upper board. these questions get asked over and over on code 62. is my battery voltage correct and is the 4v output not enough to power the board?i have  a  lot of machines and like the universals the most only problem ever has been a battery issue . ive got this machine reset before  but always got the leds on the upper board  on. machine worked perfectly when shut down./ any help would be appreciated.if the power supply is the issue can someone steer me in the right direction  to get a power supply. also can i apply 5v to the board leads as a diagnosis   for  the problem ?