The only way I did it, when recording alone, was to plug a small foot switch in the punch connector, back panel.
So, I've pushed play, waited until the right time, and stepped into the foot switch, enabling recording.
Ive never worked with the blackface but I own both an Lx-20 and a Xt. Does the blackface unit have the auto record button and set locate points? If so, set your punch points ( I believe its 2 and 4 ) and then turn on auto record, arm your track you want to correct. Should record in that section only. Like i said though, ive never messed with a blackface.
I tried just playing the track and punching in at the right time but nothing happens. How would it know what track to punch in on? If I arm the track and play it, I cant hear anything because the track is armed. So I'm confused.
Arm the track in question.
Hit "Play"(IMPORTANT! Not play and record)
When yo get to the punch in point with PLAY depressed, press the RECORD button. You are now punched in.
To get back out you can either tap the PLAY button or just hit STOP.