The 5 volts are a smooth 5 volts DC.
I'm not an electronics expert but do know this; 9.5 volts ac off the coil travels through a bridge rectifier and then Zener diode, capacitors, etc to produce a smooth 5 volts DC.
Pink wires in the machine should have a steady 5 volts DC. The MPU board has voltage sensing, if that 5 volts DC not correct it will shut itself down. Since I saw error codes on the BV board suspect the 5 v DC is ok as the board was working.
9.5 volts AC is also present in the machine and will be "grass" colored wires. (light green)
Problems with the meter displays could be many things. Board is bad, eproms are bad, voltage is bad, display is bad, wiring loose (that big black door connector have seen the pins get pushed out causing lack of contact) Have even seen screws or coins jammed behind MPU edge connectors causing shorts.
Are you getting anything at startup? Sound?
Have to go through process of elimination; check voltages from power supply, check voltage at display connector, check for anything behind the edge connectors ( this is important step, the top box has holes just above back of edge connector, stuff can fall down there)
To clarify my statement in previous post; "Tell us where your at" I meant with the machine LOL, not physical location!!