Service Adjustments - Sanyo DS13310 Service Manual

HIGH VOLTAGE CHECK
Note: +B (+135V) Voltage Check and Grayscale Adjustment
must be completed before attempting High Voltage Check.
1. Connect high voltage voltmeter negative lead to ground, and
connect + lead to anode of picture tube.
2. Tune receiver to an active channel and confirm TV is
operating properly.
3. Eliminate the beam current by adjusting the contrast and
brightness controls to minimum.
4. Confirm high voltage is within 20.0 KV and 22.0 KV. If reading
is not within range, check horizontal circuit.
No high-voltage adjustment is provided on this chassis.
HIGH VOLTAGE HOLD-DOWN TEST
Every time the receiver is serviced, the HIGH VOLTAGE
HOLD-DOWN circuit must be tested for proper operation by
following these steps:
1. Connect receiver to 120V AC line. Tune receiver to active
channel. Set the picture controls to the Auto levels.
2. Check that the voltage measured between TP7 and TE7
(ground side) is within 15.6 VDC to 19.2 VDC. If the voltage
is out of this range, the Hold-Down Circuit must be checked.
3. Connect a DC Voltage supply to TP7 and TE7 through a 100
ohm 1/4W resistor. Adjust the DC voltage to 23 VDC. The
receiver should shutdown, losing raster and sound. Then the
receiver should turn off automatically. This reaction indicates
that the Hold-Down circuit is functioning properly. If the
receiver does not shutdown, a malfunction is indicated and
its cause must be found and corrected.
4. To obtain picture again, remove the DC Supply and wait a
few minutes. Now turn on the receiver.
SERVICE ADJUSTMENTS (Continued)
VIDEO INPUT LEVEL ADJUSTMENT
Note: Video Input Level adjustment affects brightness level.
When Video Input Level adjustment is made, brightness
level must be checked.
1. Connect video signal generator output (1 Vp-p terminated at
75 ohms) to VIDEO INPUT JACK.
2. Set TV to Game Mode.
3. Connect scope to TP16A and ground.
4. Adjust Video Input Level (VR1023) for 2.0 ± 0.2 VDC.
5. Set TV to TV Mode, Picture Controls to Auto levels.
Check brightness and contrast on several active channels. If
brightness or contrast is incorrect, reset bright level.
SOUND ADJUSTMENT
1. Connect Voltmeter – lead to ground and + lead TP 20 (FM
DET OUT) on main board.
2. Tune receiver to an active channel and fine tune to obtain the
best picture.
3. Confirm D.V.M. reading of 3.85 ± 0.2 VDC.
4. If the voltage is out of this range, adjust Sound I.F. Transformer
(T131) for 3.85 ± 0.2 VDC.
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