Read Panasonic CF-28 Service Manual online
4.4. Diagnosis Map
4.4.1 MAIN UNIT DIAGNOSIS (1/2)
Make sure that connecting cables, connectors and AC adapter are not loose or disconnected prior to
testing.
testing.
4.4.2 MAIN UNIT DIAGNOSIS (2/2)
Make sure that connecting cables, connectors and AC adapter are not loose or disconnected prior to
testing.
testing.
No. Symptom
Troubleshooting
procedures
Source of
problem
Component
No.
Result
1
No power is sent to the
unit.
unit.
YES Go to No. 1-5
NO
Go to No. 1-2
Is voltage pin 4 of Q53 lower
than 1V?
than 1V?
YES
NO
If lower than 15V
D19, D20
D21, D22
D21, D22
1-2
1-1
Is 15V
applied to pins 5-8 of
Q53? (Whichever one)?
No power is sent to the
unit, (When using the
Battery Pack)
Power cuts off during
operation.
unit, (When using the
Battery Pack)
Power cuts off during
operation.
YES
If voltage is 0V
during the power
switch is set to
ON, go to No. 1-7
during the power
switch is set to
ON, go to No. 1-7
Final Means
Is 8~11.4V applied to pins
1~3 of Q50? (Whichever one)
1~3 of Q50? (Whichever one)
Main PCB
IC74
YES
If they show
soldered
completely
soldered
completely
R355, R356
R365, R367
R365, R367
1-4
1-5
Check soldered parts of
R355, 356, 365 and R367.
R355, 356, 365 and R367.
NO
2-1
IC74
YES
1-3
Before setting the power
switch to ON, check voltage
on either side of R372. Is
Voltage 3.3V?
switch to ON, check voltage
on either side of R372. Is
Voltage 3.3V?
If not 0V
NO
If voltage of
C404 is 3.3V
If lower than 3V
C404 is 3.3V
If lower than 3V
Go to No. 1-3
IC74
NO
Go to No. 1-2
R372
POWER SW
2
Component
Source of
problem
No.
Symptom
Troubleshooting
procedures
No.
Result
1
YES
Go to No. 1-2
1-1
Are there system files in the
device selected?
device selected?
When a device is selected
for “Boot Up Drive”, the
system boots from a
different device.
for “Boot Up Drive”, the
system boots from a
different device.
NO
Improper setting
YES
Device for which
the problem
occurred
the problem
occurred
1-2
Does the unit operate
normally after replacing the
problem device.
normally after replacing the
problem device.
(HDD)
IC43
(FDD/SDD)
IC43
IC47
IC47
NO
Main PCB
IC20
Main PCB
IC43
X2
RTC battery
2
2-1
Replace the Main PCB.
Date or Time cannot be
input.
Date and Time does not
change properly.
Date and Time are not
displayed.
input.
Date and Time does not
change properly.
Date and Time are not
displayed.
Main PCB
IC35~IC41
IC80~IC83
IC80~IC83
IC33
3
3-1
Replace the Main PCB.
Memory count is too large
or too small.
or too small.
AC Adapter
4 - 5
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