Mechanical. It's likely you have a broken mode motor gear or the motion of the head sled mechanism is compromised. Jeff At 10:03 AM 11/14/2017, you wrote: >This is a new one on me -- > >Tascam Mk3: I put a tape into Play. Very loud clicking happens, all >3 LEDs start flashing (Play, Pause, Record), sometimes it will >either stop playing or play really fast. FF and REW are fine. > >Would this be a logic or mechanical issue? Or both? > >TIA > >--- >This email has been checked for viruses by AVG. >http://www.avg.com