Hi,

Try using the Meridian Control Window (the PC application that come with Mconfig), that looks a Meridian remote and controls via RS232).

If that can control your processor and you see feedback messages in the app from the process this would suggest the cabling et al is ok between the PC and the 861. If not the suspect cabling.

Regards,
Carl

861v6+ID40, HD621, 8000.2, 7200HC, 7200.2, SKYQ Silver, PS3, PDP-LX6090, QNAP TS870-Pro (8*6TB), Roon, iPadAir2.
[In Reserve] C15, MD600 (2*3TB), TwinStore RM (2*2TB)