Ok. That's much clearer. The Track 1 REC button doesn't light up when pressed.
General Maxim:
If engaging multiple tracks at once a maximum of 8 Tracks can be recorded simultaneously, and a Stereo Track counts as two tracks.
But that isn't the situation in your case. You're only trying to record on one Track.
As the MUTE/SOLO functions also fail to light the Track 1 REC button:
(a) The most likely culprit is dust, moisture residue, or lint on the contact under the REC button. You may want to try applying Deoxit according to the product instructions.
(b) The next possibility is the light burned out. Turn your unit on, load your reset template song, press the REC button, then the RECORD button to see if the RECORD button lights up anyway.
(c) The least likely possibility is the contact or circuit has failed.
Is there any other way to engage record on channel 1 a that can be done without pressing the button?
There's no other way to engage recording on a Track if the REC button won't activate the recording circuit.
I've had my DP-24 for 7 years with no issues that Deoxit didn't fix, and off hand I don't recall any posts about a REC button/circuit failure.
To see if any one else has reported this issue you can do an Advanced Search of the forum using "rec button" [include the quotes]. If there are any hits they will be displayed in the Site Results tab.
Note that the search engine isn't very smart. Despite putting the search term is quotes, it may also return posts that contain only the letters "rec" or only the word "button".