On 26/02/2021 09:03, Robin wrote:
On 26/02/2021 08:40, Ian Jackson wrote:

snip

One way of finding out if an RC is actually transmitting a signal is
to hold it close to a radio with a ferrite rod aerial, and tuned to a
quiet spot on the long wave. If the RC is transmitting, you will hear
a 'burpity-burp' noise when you press the a button.

How does that detect a failure of an infrared transmitter?

you don't get any noise...try it