Daewoo 712B Service Manual page 28

9-2. Vertical Size
Abnormal
V.Size
Is
changeable the
DC voltage of
IC401 pin 1?
Yes
Trouble V.OSC/
Deflection Circuit
Refer to V.OSC/Deflection circuit
Is
No
the 3.5Vdc of pin
23 of the IC501?
No
Check the IC501 and
its ambient circuit
26
Check the IC401
Yes
and its
ambient circuit