Sony TVP-08, Training Manual

Page: 27 / 139

19
T602 Secondary (Audio B+)
Overview
The secondary winding of T602 PIT is used to develop two voltages - +/-
19 volts. These voltages are used to power the K board, which contains
all of the audio circuits.
Operation
The voltage induced into the secondary winding of T602 is used to de-
velop +/- 19 volts. This voltage is used to supply the Audio section (K
board) and is fused with PS6103 and PS6104.
This voltage is rectified by D6116 and filtered by C6121 and C6129 to
create the +19 volt supply. It is also rectified by D6114 and filtered by
C6120 and C6128 to create the –19 volts. The +19 volt supply is output
at CN6102/7 and 8. It also goes to D6122/A, which is part of the protec-
tion circuitry. The –19 volt supply is output at CN6102/2 and 3.
Troubleshooting
If the rest of the power supply is working, but there is a problem with these
supplies, you should suspect a problem on the K board. The set can be
run with CN6102 unplugged. If the correct voltages are measured at
CN6102, then the problem is on the K board. If PS6104 and PS6103 are
open, it would be a good idea to power the unit without CN6102 discon-
nected. If everything appears to be OK, check the K board for shorts on
the +/- 19 volt lines. If none are found, then plug CN6102 in and power up
the unit.