APM 2.5 No longer responding to 3DR radios

Upgraded one of my APM 2.5 to the latest Arduplane through USB, was able to calibrate, set-up RC, etc., but when I attempt to connect via 3DR radio’s it won’t download the parmerters. The MP screen shows movement on the artificial horizon but can’t get past connection screen. Get stuck at “Getting Params., (Sysid compid 1)” then times out. I’m on the right com port and 57600 baud.


Disregard, my Y harness for OSD and Radios was on the wrong plug.

Glad to see your problem solved! :wink:
Can you explain how can I check my “y harness for OSD and Radios”?