Preparation For Servicing - Philips VR340/55 Service Manual

PREPARATION FOR SERVICING

How to Enter the Service Mode
About Optical Sensors
Caution:
An optical sensor system is used for the Tape Start
and End Sensors on this equipment. Carefully read
and follow the instructions below. Otherwise the unit
may operate erratically.
What to do for preparation
Insert a tape into the Deck Mechanism Assembly and
press the PLAY button. The tape will be loaded into
the Deck Mechanism Assembly. Make sure the power
is on, connect TP507 (SENSOR INHIBITION) to GND.
This will stop the function of Tape Start Sensor, Tape
End Sensor and Reel Sensors. (If these TPs are con-
nected before plugging in the unit, the function of the
sensors will stay valid.) See Fig. 1.
Note: Because the Tape End Sensors are inactive, do
not run a tape all the way to the start or the end of the
tape to avoid tape damage.
Q504 Q505
TP507
S-INH
Fig. 1
1-5-1 HE274PFS