Problem with DME

Does anyone have any insight as to my problem.

I just some work done on my Arrow which included removing the engine mount for
repairs.

On my second flight the transponder went out and would not reset. After appox.
2 minutes it came back on and has been working flawlessly for the past 4 hours
of flight. The DME however is not working. The display will come on, you can
enter freq. but nothing shows but dashes other than the freq. I looked under
the dash and no wires seem to be pulled away and the antenna connections look
good.

I believe the transponder and the DME operate on the same antenna. Could the
splitter be bad or the antenna if both leads connect to it? Any ideas before I
take it to the avionics shop.

Thank you,
Larry