Sanyo DS19310 Service Manual

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Contents

Sanyo DS19310 Service Manual Manual pdf 9 page image

— 7 —VCO ADJUSTMENTNote: VCO must be adjusted after IC101 (SignalProcessor), IC802 (EEPROM) or T151 (VCO Coil) isreplaced.1. Tune receiver to an active channel.2. Set the picture controls to the Auto level.3. Connect digital voltmeter + lead to pin 58 of IC101 and– lead to ground (TE 7).4. Confirm a reading of 3.6 ± 0.2 VDC.5. If voltage is out of specifications adjust T151 for3.6 ± 0.2 VDC.RF AGC ADJUSTMENT1. Tune receiver to strongest VHF station in your area.2. Set contrast and brightness controls for maximum.3. Turn off the receiver and disconnect the AC power cord(120V AC line).4. While pressing the MENU key, reconnect the AC powercord. The Service Menu display will now appear.5. Select NO. 42 RAD (RF AGC Delay) with or key.6. Adjust the data with + or – key in the direction whichcauses snow to appear; then in the opposite directionuntil the snow just disappears.7. To turn off the Service Menu display, press the MENU key.BRIGHTNESS LEVEL ADJUSTMENTNote: Grayscale, RF-AGC, Video Level, and High Voltage Checkmust be adjusted before attempting Brightness LevelAdjustment.1. Connect a color-bar generator to the antenna terminals.2. Switch the generator to the crosshatch pattern.3. Reset the picture controls to the Auto levels.4. Connect voltmeter (high impedance) + lead to terminalTP51 and – lead to terminal TP50 on main board. Setvoltmeter for 1.5V ~ 3V range.5. Turn off the receiver and disconnect the AC power cord(120V AC line).6. While pressing the MENU key, reconnect the AC powercord. The Service Menu display will now appear.7. Select NO. 47 SB (Sub Brightness) with or key.8. Adjust the data with + or – key for 820 mVDC.9. Press the MENU key to turn off the Service Menu display.10. Check brightness level on every active channel, readjust(repeat steps 5 ~ 9), if necessary.Note: Do not set to excessive brightness level, otherwisethe contrast level will be suppressed.HIGH VOLTAGE HOLD-DOWN TESTEvery time the receiver is serviced, the HIGH VOLTAGEHOLD-DOWN circuit must be tested for proper operation byfollowing these steps:1. Connect receiver to 120V AC line. Tune receiver to activechannel. Reset the picture controls to the Auto levels.2. Check that the voltage measured between TP7 and TE7(ground side) is within 16.5 VDC to 21 VDC. If the voltageis out of this range, the Hold-Down Circuit must be checked.3. Connect a DC Voltage supply to TP7 and TE7 through a100 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. Thisreaction indicates that the Hold-Down circuit is function-ing properly. If the receiver does not shutdown, amalfunction is indicated and its cause must be found andcorrected.4. To obtain picture again, remove the DC Supply and waita few minutes. Now turn on the receiver.HIGH VOLTAGE CHECKNote: +B (+135V) Voltage Check and Grayscale Adjustmentmust be completed before attempting High VoltageCheck.1. Connect high voltage voltmeter – lead to ground, andconnect + lead to anode of picture tube.2. Tune receiver to an active channel and confirm TV isoperating properly.3. Eliminate the beam current by adjusting the contrast andbrightness controls to minimum.4. Confirm high voltage is within 25.0 KV and 27.0 KV. Ifreading is not within range, check horizontal circuit.No high voltage adjustment is provided on this chassis.