Read Sharp XG-MB70X (serv.man13) Service Manual online
36
XG-MB70X
Checking the peripheral circuits of the
microprocessor
microprocessor
Are the voltages of approx. 3.3V and 2.5V
applied to both ends of C2030 and C2029
respectively?
applied to both ends of C2030 and C2029
respectively?
Go to "Checking the power supply
system".
system".
Are the oscillations of 133MHz and
64MHz output from pin (3) of X2001 and
pin (3) of X2002 respectively?
64MHz output from pin (3) of X2001 and
pin (3) of X2002 respectively?
Check the peripheral circuits of X2001
and X2002.
and X2002.
Does each terminal of R2039, R2040,
R2042, R2048 and R2050 change?
R2042, R2048 and R2050 change?
Check IC2201 and IC2202. IC2003 is
defective.
defective.
Do pins (95) and (96) of IC2201 change?
Check IC2203. IC2201 is defective. The
I2C bus does not function normally.
I2C bus does not function normally.
Do pins (74) to (77) and (89) to (94) of
IC2201 change when any key is
operated?
IC2201 change when any key is
operated?
IC2201 is defective. The keys do not
function normally.
function normally.
When the power button is pressed, does
the voltage of pin (7) of IC2005 become
3.3V?
the voltage of pin (7) of IC2005 become
3.3V?
IC2003 is defective.
Do pulse-shaped waveforms appear at
pins (1), (2), (5) and (6) of IC2005?
pins (1), (2), (5) and (6) of IC2005?
IC2005 is defective.
Does the voltage of pins (2) and (6) of
IC2006 and pins (3) and (6) of IC2007
change?
IC2006 and pins (3) and (6) of IC2007
change?
IC2006 or IC2007 is defective.
Is the voltage of pin (9) of IC3560 5V?
IC3560 is defective.
Does the fan rotate?
Check the power supply circuit or fan
circuit on the main circuit.
circuit on the main circuit.
Go to "Checking the lamp light-up".
NO
YES
NO
YES
NO
YES
NO
YES
NO
YES
NO
YES
NO
YES
NO
YES
NO
YES
NO
YES
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