And just when it's all going swimmingly...tapping the CPU causes system re-sets, garbled display and system shutdown. I rebooted and repeated, same thing.
Pulled CPU found quite a lot of oxidisation on the CPU pins, the socket was fine. This is an OEM CPU. So, I cleaned the pins as best as I could, re-seat, all now good. Tapping, no issue now.
The system had passed multiple boot and slew tests before this showed up.
Glad to have found this before sending back but I am a little surprised. Gremlins at every corner. Final testing, RS232; ST4; system slews RA/DEC now all good, DEC motor behaving as it should. Oh and it also passes the tapping test!
