Service manual

Pin6 (BDRV) is floating
Pin8 (HDRV) is floating
Pin12, 13 ( VOUT 12, 13) are floating
Vertical Oscillator
The vertical free –running frequency is determined by the resistor C613 at pin24. Usually the free-running
frequency should be lower than the minimum trigger frequency.
4-3 TRANSISTOR & DIODE CIRCUIT
LOCATION CIRCUIT FUNCTION DESCRIPTION
D901 ~ D904 Bridge Rectifier for AC Source
D910 Clamp Diode for Snubber CKT
D918, D919 Rectifier for Output Voltage
D922 Rectifier for Output Voltage
D923 Rectifier for Output Voltage
D925 Rectifier for B+ Supply
Q901 MOS FET for Switching Power Control.
Q907, Q908 Use for Off-Mode to Cut-off 6.3V Supply Voltage
Q909, Q918 Use for Standy-By or Suspend Mode to Cut-off 12V Supply Voltage
Q912, Q920 Push-Pull Topology to Drive Q911
Q913 Degaussing Switcher Transistor
Q921 5V Regulator Transistor
Q701 Turn-on at Power ON/OFF and Change Mode to Protect Hor.Block
Q402 HOR. Driver Transistor
Q426 Horizontal s correction control MOSFET
Q404, Q405 As Differential Amp. to Drive Q406
Q406 Transistor for H-Size Control
Q705 Brightness Control CKT
X-ray Protection
The X-ray protection input pin2 provides a voltage detector with a precise threshold. If the voltage exceeds this
threshold for a certain time, an internal latch switches the whole IC into protection mode. In this mode several
pins are forced into defined states:
11
ViewSonic Corporation Confidential
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Do Not Copy E70-11