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6
AGC Adjustment
Receive 60dBµ (1mV) VH colour bar pattern signal.
Select RF AGC item.
Adjust value, to noise reduce gradually and just disappeared point.
CRT cut off and white balance adjustment
a) CRT cut off adjustment
1. Select item VG2B, then adjust value to 32.
2. PRESS “MENU” key to page 2, when the screen shows”VK” adjust the SCREEN control on Fly back
transformer to make the screen show alternating flashing characters to darkle.
b) White balance adjustment
1. Receive a Black and White pattern.
2. Adjust
RC
, GC, BC,RD,BD items to get colour temperature 9300K
±
3 JND.
A3. Error Detection Process
1.
Check to see if
Fuse is normal
No light and sound
Abnormal
Check D901~D904,
C914, IC9601, Q901
Check to see if the
collector voltage of
D909 is 13.5V
The failure ofhorizontal unit
orN204
Check to see
if , ZD201 8v,
is normal
Check the control
voltage of Q207 or
CPU power pin
Check IC602 ,ect
Normal
Normal
Normal
Abnormal
Check to see 110V
、
180V
etc. voltage is normal
Test to see all terminal
Resistance of load
Check switch
power unit
Check to see if
rectifying tube
is normal
Check the
Loader
Change
rectifying diode
Abnormal
Normal
Abnormal
Normal
Abnormal
Normal
Abnormal
The failure of horizontal
unit or IC201
Maintenance Service and Trouble shooting