Electronic Partners UK » Celestron nexstar evolution 9.25 Celestron CEV0100 REV F 9.9 volts enter circuit board from battery pack 12.1 volts enter board from the mains charger but when you multimeter the switch terminal in the board the meter reads 0.5volts. Also if you leave the new battery pack connected to the circuit board and leave it for a few days the battery goes flat and then the battery management system cuts in and puts the battery to sleep then you have to charge the batteries bypass the battery pcb and then power up the battery pcb to wake up the battery pack.I do hope you come up with a solution as a replacement board is not an option,many thanks Adrianaders repair in Edenbridge