Sanyo DS31520 Service Manual

Also see for DS31520: Owner's manual Owner's manual

Contents

Sanyo DS31520 Service Manual Manual pdf 7 page image

— 7 —ANTENNA CONNECTIONSThis receiver is designed for UHF/VHF reception. A 75 ohmterminal is provided for UHF and VHF receptions. Whenconnecting a CATV antenna system, connect the 75 ohmcoaxial cable directly to the 75 ohm terminal. For 300 ohmVHF antenna, use an adapter (not included with the TV set).CIRCUIT PROTECTIONFuse F601 (4A) is included in the AC line. This fuse must bereplaced with the proper fuse (see Parts List).+B VOLTAGE CHECKConnect Voltmeter + lead to TJ1 130V and – lead to ground(TE7). Connect receiver to AC 120V line. Tune receiver to anactive channel. Reset the picture controls to the FACTORYPRESET levels (press remote control RESET key twice).Voltage must measure between +128.0V and +132.0V. If thevoltage is out of this range, the power circuit must bechecked. No +B adjustment is provided on this chassis.HORIZONTAL WIDTH ADJUSTMENT1. Tune receiver to an active channel.2. Check the picture for proper width. If width is not correct,perform steps 3 ~ 6.3. 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. 47 EWD (EW DC) with or key.6. Adjust the data with + or – key for proper width.To turnoff the Service Menu display, press the MENU key.HORIZONTAL CENTERING ADJUSTMENT1. Tune receiver to an active channel.2. Check that picture is in the horizontal center of TV screen.If picture is not centered horizontally, perform steps 3 ~ 6.3. Turn off the receiver and disconnect the AC power cord.4. While pressing the MENU key, reconnect the AC powercord. The Service Menu display will now appear.5. Select NO. 03 HP (Horizontal Phase) with or key.6. Adjust the data with + or – key for horizontal center. Toturn off the Service Menu display, press the MENU key.VERTICAL SIZE ADJUSTMENT1. Tune receiver to an active channel.2. Check the vertical size of the picture. If the vertical size istoo large or small, perform steps 3 ~ 6.3. Turn off the receiver and disconnect the AC power cord.4. While pressing the MENU key, reconnect the AC powercord. The Service Menu display will now appear.5. Select NO. 04 VS (Vertical Size) with or key.6. Adjust the data with + or – key for full scan. To turn offthe Service Menu display, press the MENU key.VERTICAL CENTERING ADJUSTMENT1. Tune receiver to an active channel.2. Check that picture is in the center of TV screen. If picturecenter is too low, change resistor R513 from 1K ohm 1/2W to470 ohm 1W. If picture center is too high, remove resistorR513 (1K ohm, 1/2W).VCO ADJUSTMENTNote: VCO must be adjusted after IC101 (Signal Processor),IC802 (EEPROM) or T151 (VCO Coil) is replaced.1. Tune receiver to an active channel.2. Set the picture controls to the Sports 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.VIDEO LEVEL1. Connect color-bar generator to antenna terminals.2. Turn off the receiver and disconnect the AC power cord(AC 120V line).3. Connect oscilloscope to TP16 (Q202 emitter) and ground.4. While pressing the Menu key, reconnect the AC powercord. The Service Menu will now appear.5. Select NO. 46 VL (Video Level) with the or key.6. Adjust the + or – key for an oscilloscope reading of 1.0 ±0.1 VP-P at TP16. Press the MENU key to turn off theService Menu display.CAUTION FOR CONTINUED PROTECTION AGAINSTA RISK OF FIRE, REPLACE ONLY WITHTHE SAME TYPE 4A, 125V FUSE.ATTENTION : POUR MAINTENIR LA PRO-TECTION CONTRE LES RISQUESD’ INCENDIE UTILISER UN FUSIBLE DERECHANGE DE MEME TYPE 4A, 125V.4A 125V1.0 ± 0.1 VP-PFigure 4.