Toshiba CF3254J Service Data page 10

CIRCUIT ADJUSTMENT
HV REGU BOARD ADJUSTMENT
HIGH VOLTAGE CHECK
CAUTION: There is no HIGH VOLTAGE ADJUSTMENT
on this chassis. Checking should be done following the
steps below.
1. Connect an accurate high voltage meter to the
second anode of the picture tube.
2. Turn on the receiver. Set the BRIGHT and
CONTRAST Controls to minimum (zero beam
current).
3. High voltage must be measured below 30.7 kV.
4. Rotate the BRIGHT Contro! to both extremes to be
sure the high voltage does not exceed the limit
under any conditions.
+115V POWER SUPPLY ADJUSTMENT
CAUTION: This voltage is closely relates to the high
voltage. To prevent hazardous X-RAY RADIATION,
this voltage must be properly adjusted to +115 volts.
. Tune in an air signal and press the RESET button.
. Check that AC power line voltage is normal (120V
ac, 60 Hz).
. Connect a MULTI-METER (DC VOLT range) to Vcc
terminal (emitter of Q480) and chassis ground.
. Adjust +115V ADJ. (R450) for +115 volts reading.
kk oO N=
SIDE DPC ADJUSTMENT
1. Receive crosshatch pattern with a color bar
generator.
2. Adjust the SIDE PIN control (RD51) for straight line
at the right aqnd left sides of the pattern.
WIDTH ADJUSTMENT
Adjust the WIDTH control (RD50) so the picture width
does not lack on right and left sides when BRIGHT-
NESS control is varied from minimum to maximum.
FS CIRCUIT CHECK
The Fail Safe (FS) circuit check is indispensable for the
final check in servicing. Checking should be done
following the steps below.
1. Turn the receiver on and press the RESET button.
2. Temporarily short TP-®@ and TP-@ on the HV REGU
Board with a jumper wire.
Raster and sound will disappear.
3. The receiver must remain in this state even after
removing the jumper wire. This is the evidence that
the FS circuit is functioning properly.
4. To obtain a picture again, temporarily turn the
receiver off and allow the FS circuit more than 5
seconds to reset. Then turn the power switch on to
produce a normal picture.
Troubleshooting Guide for Fail Safe Circuit
Check that the set returns to normal operation when
terminal 11 on the HV REGU Board is grounded with
jumper wire.
Faulty power
circuit or Hori-
zontal circuit.
Check the voltage at pin 8 of
Q842 on the HV REGU Board
is approximately 9.1 volts.
YES
NO
Defective Fail Safe Circuit
40