Service manual

6
The AC power line voltage should be accurately kept during alignment.
During the process of alignment, the AC voltage should be kept in the range from 215V to 225V (50Hz).
Do not attempt to connect or disconnect any wire while the receiver is in operation. Make sure the power cord is
unplugged before replacing any parts in the receiver.
Unless specified, start adjustments after the receiver is turned on for at least 30 seconds.
CHASSIS'S TOP VIEW
VR 501
MAIN CHASSIS PC BOARD
T901
NOTICE:
1. Resistor
All resistors are of 1/8W Carbon Film type except those listed below. The unit of measure for resistor is OHM
(K = 1,000 ohm, M = 1,000,000 ohm).
CARBON FILM RESISTOR
CARBON COMPOSITION RESISTOR
METAL OXIDE RESISTOR +5%
METAL OXIDE RESISTOR +2%
FUSIBLE RESISTOR
NON-INFLAMMABLE RESISTOR
PTC THERMISTOR
VARIABLE RESISTOR
2. Capacitor
All capacitors are of 50V Ceramic type except those listed below. The unit of measure for capacitor is
FARAD (F) (UF = 0.000001 F, PF = UUF = 0.000001 UF)
CERAMIC CAPACITOR
TANTALUM CAPACITOR
POLYESTER FILM CAPACITOR
POLYPROPYLENE FILM CAPACITOR
ELECTROLYTIC CAPACITOR
TRIMMER CAPACITOR
METAL POLYESTER FILM CAPACITOR
3. Unit of Measure: UH
4. Test Point
5. Marking of Ground Wire
: Ground wire of chassis (COLD)
: Ground wire of external wire (HOT)
6. Voltage Measurement
The voltages at all points should be measured with a digital multi-meter, and the measuring conditions are as
follows:
Power Source: AC220V 50Hz
Receiving Signal: Color Bar Signal
All Control Buttons: in Normal Position
7. Waveform
The numeral in the small circle represents the number of waveform, refer to the waveform table.
8. It is easy to locate a connection point in the direction as indicated by arrow (↗).
9. The schematic diagram in this manual is drawn according to the original design. It may be slightly different from the
actual circuit of the receiver because of any change in the circuit subject to no prior notice.
Notice: This circuit has a transformer to isolate the power supply circuit from the majority of the other circuit, and
they can be identified in the schematic diagram by marking with "HOT" and "COLD”. Please note the
followings .All circuits are "COLD" except power supply circuit
.
(1) To avoid electric shock hazard, never touch the "HOT" and "COLD" circuit simultaneously.