Sanyo DS24424 Service Manual

Also see for DS24425: Owner's manual Owner's manual Owner's manual

Contents

— 9 —GRAYSCALE ADJUSTMENT1. Set the picture controls to the Auto levels or Reset (useMENU key and or key or RESET key).2. Turn off the receiver and disconnect the AC power cord(120V AC line).3. While pressing the MENU key, reconnect the AC powercord. The Service Menu display will now appear.4. Select NO. 49 RB (Red Bias), NO. 4A GB (Green Bias),and NO. 4B BB (Blue Bias) with or key and set eachdata to 0 with + or – key.5. Select NO. 4C RD (Red Drive) and NO. 4E BD (Blue Drive)with or key and set each data to 40 with + or – key.6. Set NO. 4D GD (Green Drive Reduction) data to 08, NO. 3ESB (Sub-Brightness) data to 18, NO. 3C SCO (Sub Color)data to 15, NO. 3D STI (Sub Tint) to 05, and NO. 3F SSH(Sub Sharpness) data to 00 with or , and + or – keys.7. Turn Screen Control (T402) to minimum (fully counter-clockwise).8. Select the Service Menu NO. A9 (No Vertical Sweep)with or key.9. Advance Screen Control (T402) clockwise to obtain justvisible one color line. If line does not appear, place thiscontrol to maximum (fully clockwise).10. Raise each Bias Level with 3, 6, and 9 keys to obtain justvisible white line. See Figure 5.11. Select the Service Menu NO. A8 DRV (Drive Adjustments)with or key.12. Adjust Red and Blue Drive Levels alternately with 1, 3,7, or 9 key to produce normal black and white picture inhighlight areas. See Figure 6.13. Check for proper grayscale at all brightness levels.To turn off the Service Menu display, press the MENU key.Note: If Grayscale Adjustment is made after picture tubereplacement, check Brightness Level Adjustment.FOCUS ADJUSTMENTAdjust focus control (T402) for well defined scanning lines.HIGH VOLTAGE CHECKNote: +B (+130V) 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 contrastand brightness controls to minimum.4. Confirm high voltage is within 28.0 KV and 31.1 KV. Ifreading is not within range, check horizontal circuit.No high voltage adjustment is provided on this chassis.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.6. While pressing the MENU key, reconnect the AC powercord. The Service Menu display will now appear.7. Select NO. 3E SB (Sub Brightness) with or key.8. Adjust the data with + or – key for 680mVDC.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.1 2 34 5 67 98RB(–) RB(+)BB(–) BB(+)(N/A)GB(–) (N/A) GB(+)(N/A)FOR RED BIAS ADJUSTMENTFOR BLUE BIAS ADJUSTMENTFOR GREEN BIAS ADJUSTMENTFigure 5. Remote Control Number keys’ functions inService Menu NO. A9 (No Vertical Sweep)1 2 34 5 67 98RD(–) RD(+)BD(–) BD(+)(N/A)(N/A) (N/A) (N/A)(N/A)Figure 6. Remote Control Number keys’ functions inService Menu NO. A8 DRVFOR RED DRIVE ADJUSTMENTFOR BLUE DRIVE ADJUSTMENT