Originally Posted by Johnt49

Could be the relays on the CCU board. Sounds like the contacts are dirty causing intermittent contact. If you remove the CCU and disassemble it you'll see some relays soldered to the board. You can clean them with a small picce of 400 wet/dry paper folded over to clean both sides of the contacts at once. It happened to mine. Been over a year now and still working well.