Had a technical malfunction on the runway once.
CAPT went back to idle to check and I on the mic to tell tower we needed 30 more seconds to figure out.
Reply: No worries and to the aircraft in approach. Expect late landing clearance, prepare for go-around runway still blocked.
The guys acknowledged. Unable for a quick fix we told TWR that we would taxi forward for the next exit to sort out the problem OFF the runway. Other aircraft landed.
My opinion: Whatever you do, just let the other party (ATC) know in a timely manner. Never had a problem so far.