Not even to a telnet? Can you keep the telnet window open and use atop to see if it's transmission that's consuming all the resources? Also, try to leave another telnet window open, where you can run a transmission-daemon -f command and see the output of transmission log.
Synology System 1:
1 DS212 / 1 Samsung F4 HD204UI 2TB, powered 24h/day, 365 days/year on
Synology System 2:
1 DS2411+ (in building process ...)