Electrical Adjustment - Haier HT-3768 Service Manual

VII. ELECTRICAL ADJUSTMENT

A. Safety precautions

1. It is safe to adjust after using insulating transformer between the power supply

and chassis input to prevent the risk of electric shock and protect the instrument.

2. Never disconnect leads while the TV receiver is on.

3. Don't short any portion of circuits while power is on.

4. The adjustment must be done by the correct appliances. But this is changeable in

view of productivity.

B. Adjustment procedure

The chassis of this TV set uses Toshiba IC with the latest digital bus processing

technology. The adjustment points are fewer and the adjustment is simpler. The

adjustment method is as follows:

1. +B: 115±0.3V adjustment.

1) Switch on the power and connect PAL circular signals to the tuner.

2) Adjust variable resistor RP501 until the voltage of the main power is 115±0.3V.

2. Screen voltage adjustment.

1) Switch on the power and receive PAL system circular signal. Warm up the TV set

for 15 min.

2) Enter the adjustment D state. Press the "-/--" button, then a bright horizontal line

appears. Adjust screen potentiometer to let the horizontal line just appears.

3. Focus adjustment.

1) Receive electronic circular signal.

2) Set picture mode on standard mode.

3) Adjust focus potentiometer until the optimum picture is achieved.

4. White balance adjustment.

1) Set the picture mode on standard mode.

2) Enter the D state and adjust RCUT, GCUT, BCUT, GDRV and BDRV.

3) Coordinate of reference white color: (X=0.281, Y=0.311).

6. Adjustment of horizontal and vertical position and size.

1) Switch on the power and connect the signals to the tuner to receive PAL/NTSC

system circular signal.

2) Enter the D state. Adjust HPOS to change the horizontal position and VP50 to

change the vertical position. Adjust HIT to change the vertical size until the

vertical size is 90-92%. Horizontal size is related to the capacitor C416. Hold the

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