Have you confirmed signals from the antenna are good by moving the cable from the ANT connector to the RX2 connector?
If so, and if you've reset the database with no improvement, the next step after that would be to reload the firmware. That's a bit of a Hail Mary, but stranger things have happened than corrupt firmware.
If that does not work then it's probably not the T/R relay because it's not stuck in TX either. That would imply that ALL of your antenna selection relays have failed, a very unlikely state of affairs.
It could possibly be a loose cable between the Orion board and the PA/RF board. If that cable was loose then relays and stuff would not switch on the PA/RF board. That's easy to check.
It may be worth becoming familiar with the schematics. They are posted in the schematics section of this forum.
To drop the front and rear panels so you can look inside...
Step 1: Front Panel Disassembly
This is necessary so that the bottom plate can be slid forwards and backwards for access.
a. Remove all of the fasteners from the front panel.
b. Carefully pull and wiggle on the rear body of the power switch until it detaches from the power switch button. I apologize for not having a better description of this process, but even a video would not provide information on how it feels to do this. WARNING: be careful not to snap the mounts off of the switch body. It should not be necessary to use any tools.
c. Lay the front panel aside.
Step 2: Rear Panel Disassembly
a. Remove all of the nuts and lock washers from the BNC connectors on the rear panel.
b. Remove all of the rear panel fasteners.
c. Pull the rear panel away from the radio.
There's a ribbon cable that connects the two boards.
A nice description of the full disassembly process is
here. It's for the 100D but it's the same for the 200D.