With no schematic and having never worked on this model before, I decided to ask over on the Tapeheads.net forums. I told them the issue and Sam Palermo, Chief Engineer, at Skywave Tape Deck Repair out of Chicago jumped right in. He said the two micro switches on the tensioning arms are notorious for going bad and how to trouble shoot without a schematic.
In short order, I did verify 24VDC coming off the power supply board pin 43 (green wire) that goes to the left micro switch. The voltage looked good going to the right micro switch (white wire), but as soon as the right switch closes, it dropped the voltage to 2 volts, that goes back to the power supply board pin 29 (yellow wire).
Yes, the micro switches are bad. They couldn't pass the voltage once any current was needed. I verified this by just jumping from pin 43 to 29 with a clip lead.
In short order, I did verify 24VDC coming off the power supply board pin 43 (green wire) that goes to the left micro switch. The voltage looked good going to the right micro switch (white wire), but as soon as the right switch closes, it dropped the voltage to 2 volts, that goes back to the power supply board pin 29 (yellow wire).
Yes, the micro switches are bad. They couldn't pass the voltage once any current was needed. I verified this by just jumping from pin 43 to 29 with a clip lead.
