Can't change output on DVD from channel 3 to 4
I just got this old Broksonic DVCR 810 DVD/VCR combo and it has no switch on the back to change the output from channel 3 to channel 4. I don't have a manual so I don't know if this can be done electronically or manually. Help.
Televison & Video - Broksonic - DVCR-810 DVD Player/VCR