ViewSonic P90F Service Manual page 36

SECTION 5
Display is Vertical. Line
(No Horizontal output)
Drain of Q402 Proper ?
Is output of Q400,Q421
Is output at Pin 28 of
ViewSonic Corporation
DC at Source of
Q402 =
190Vapprox.
YES
Is waveform at
NO
proper ?
NO
I301 proper ?
NO
NO
Check SMPS DC output
(SECTION 1)
YES
REPLACE I301
32
Confidential – Do Not Copy
Check Q433
short?, and is Q433
output proper ?
NO
Is Q404 output
proper ?
NO
Is output at Pin 26of
I301 proper ?
NO
P90f-1