Compaq MV7540, Service Manual

Page: 16 / 49

HP MV7540
16
6-2. No Raster, No High Voltage, Indicator Is Orange
(1)Indicator is orange when there is
no signal
Check if the voltage at
pin5 of IC101 is normal.
Cut pin5 of IC101, then
check if it is normal.
Check the voltage at pin4
of IC101 is 4.7V
Replace IC101
Check the circuit of 5v power
supply circuit as Q904,
D103,ZD902.
Check the reset circuit
Replace X101
Check the bus
Replace IC102.
(2)No signal is normal but it is orange when there is
signal input.
Check if H,V sync inputs at pin41,pin42 of
IC101 are normal with oscillograph.
Replace IC101
Check signal cord, R172, ZD103,
R132, ZD104 and host.
Abnormal
YES
YES
NO
YES
NO
YES
NO
(3)No signal is normal but it is orange
when there is signal input.
Check if it is high level at pin16 of
IC101when there’s no signal input.
Check the relative circuit