Samsung CW-28D83 free download

File name SAMSUNG CW-28D83_serv_mode.pdf

Alignment and Adjustments 4. Alignment and Adjustments 4-1 General Alignment Instructions 1. Usually, a color TV-VCR needs only slight touch-up adjustment upon installation. Check the basic characteristics such as height, horizontal and vertical sync and focus. 2. Observe the picture for good black and white details. There should be objectionable color shading; if color shading is present, demagnetize, perform purity and convergence adjustments described below. 3. Use the specified test equipment or its equivalent. 4. Correct impedance matching is essential. 8. To protect against shock hazard, use an isolation transformer. 5. Avoid overload. Excessive signal from a sweep generator might overload the front-end of the TV. When inserting signal markers, do not allow the marker generator to distort test results. 6. Connect the TV only to an AC power source with voltage and frequency as specified on the backcover nameplate. 7. Do not attempt to connect or disconnect any wires while the TV is turned on. Make sure that the power cord is disconnected before replacing any parts. 4-2 Automatic Degaussing A degaussing coil is mounted around the picture tube, so that external degaussing after moving the TV should be unnecessary. But the receiver must be properly degaussed upon installation. The degaussing coil operates for about 1 second after the power is switched ON. If the set is moved or turned in a different direction, the power should be OFF for at least 10 minutes. If the chassis or parts of the cabinet become magnetized, poor color purity will result. If this happens, use an external degaussing coil. Slowly move the degaussing coil around the faceplate of the picture tube and the sides and front of the receiver. Slowly withdraw the coil to a distance of about 6 feet before turning power OFF. If color shading persists, perform the following Color purity and Convergence adjustments. 4-3 High voltage Check CAUTION : There is no high voltage adjustment on this chassis. The B+ power supply should be +135 volts (with full color- bar input and normal picture level). 1. Connect a digital voltmeter to the second anode of the picture tube. 2. Turn on the TV. Set the Brightness and Contrast controls to minimum (zero beam current). 3. Adjust the Brightness and contrast controls to both extremes. Ensure that the high voltage does not exceed 32 KV under any conditions. Samsung Electronics 4-1 Alignment and Adjustments 4-4 Dynamic Focus Adjustment 1. A dynamic focus adjustment should be done after replacing the CRT PCB, FBT or CRT. 2. Input a crosshatch pattern. 3. Enter " STANDARD " in video mode. 4. Turn the Dynamic focus VR fully clockwise (maximum).( ) 5. Turn the Static focus VR fully counterclockwise (maximum).( ) 6. Slowly turn the static focus VR counterclockwise. Adjust until the vertical line in the middle of the screen has maximum clarity.( ) 7. Slowly turn the dynamic focus VR (clockwise) and adjust the 3rd horizontal line for maximum clarity.