Service manual

iii
Contents
1. Circuit description......................................................................................................................... 1-1
1.1 Power block......................................................................................................................... 1-1
1.1.1 Outline ...................................................................................................................... 1-1
1.1.2 Rectifying circuit and higher harmonics suppression (active filter) circuit ...... 1-1
1.1.3 Sub power circuit ...................................................................................................... 1-2
1.1.4 Main power circuit..................................................................................................... 1-2
1.1.5 Demagnetizing circuit............................................................................................... 1-2
1.1.6 Power management circuit ...................................................................................... 1-2
1.2 Deflection processor block ................................................................................................ 1-3
1.2.1 Deflection processor (IC601) .................................................................................. 1-3
1.2.2 Pressure-reduction type horizontal deflection power circuit (IC5C0)............... 1-3
1.2.3 Horizontal width control circuit ............................................................................... 1-3
1.2.4 Vertical deflection circuit ......................................................................................... 1-3
1.2.4.1 Sawtooth waveform generation, vertical size/position control, and
linearity control circuit ............................................................................... 1-3
1.2.4.2 Vertical output amplification circuit ......................................................... 1-4
1.2.5 High voltage block .................................................................................................... 1-4
1.2.6 DBF (Dynamic Beam Focus) circuit ....................................................................... 1-5
1.3 Video block .......................................................................................................................... 1-6
1.3.1 Video signal amplifier circuit................................................................................... 1-6
1.3.1.1 Video clamp................................................................................................. 1-6
1.3.1.2 Video blanking ............................................................................................ 1-6
1.3.1.3 Video mixing/amplifying............................................................................. 1-6
1.3.1.4 Control of contrast and white balance .................................................... 1-6
1.3.2 Cut-off control circuit................................................................................................ 1-7
1.3.2.1 Control of brightness.................................................................................. 1-7
1.3.2.2 Control of BIAS ........................................................................................... 1-7
1.3.3 OSM (On Screen Manager)..................................................................................... 1-7
1.3.4 Asset circuit ............................................................................................................... 1-8
1.3.5 AUTO-SIZE function................................................................................................. 1-8
1.3.6 SB MODE (Super Bright Mode) function............................................................... 1-8
1.3.6.1 Adjustment item/operating function in selecting SB Mode .................. 1-8
1.3.6.2 Circuit (cathode) operation in selecting SB Mode [Window pattern].. 1-9
1.3.6.3 SB Mode setting data and control method ............................................. 1-9
1.3.7 CONSTANT BRIGHTNESS function ...................................................................... 1-9
1.4 CRT compensation block ................................................................................................... 1-10
1.4.1 Rotation circuit .......................................................................................................... 1-10
1.4.2 Corner purity circuit .................................................................................................. 1-10
1.4.2.1 Corner purity circuit operation.................................................................. 1-11