Service manual

3.4.8 MPU Operation Error
Check the voltage at Pin 3 of IC100 on the MAIN PWB.
NG
OK
Expected failure point
The power circuit (See Item 3.4.1)
Confirm that the voltage at Pin 12 of IC102 on the MAIN PWB is
maintained at approx. 5V.
NG
OK
Check the reset voltage.
Expected failure point
IC100 on the MAIN PWB or C100
Confirm that a sinusoidal waveform of approx. 3
to 5V
p
-
p
is
g
enerated at a fre
q
uenc
y
of 20MHz.
NG
OK
Check the waveform at Pins 17 and 18 on the MAIN PWB.
Expected failure point
X100 on the MAIN PWB or IC102
NG
OK
Check the sync. signal.
Expected failure point
Check sync. failure. (See Item 3.2.3)
Confirm that there are horizontal sync (5Vp-p) input to Pin 36 and
vertical sync. (5Vp-p) input to Pin 33 of IC102 on the MAIN PWB.
Expected failure point
IC102 on the MAIN PWB
Check the 5V line.
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