Y108540-8
Service Manual
4-19
4.14 BUZZER CIRCUIT
The buzzer is activated by signal P141 provided by the CPU. This normally Low signal goes High on 2 conditions:
• On an error tone, P141 goes High until the error condition is cleared.
• On a key pip tone, P141 goes high and then returns to its Low State.
This pulse is of an extremely short duration.
4.14.1 BUZZER TROUBLESHOOTING
PROBLEM
CORRECTIVE ACTION
The buzzer does not
Check the voltage at point (1) in the figure above:
sound when [Feed]
•
If DC +30.0V is not correctly output, check the power supply circuit.
is pressed.
•
If DC +30.0V is correctly output, replace the mainboard.
Fig. 4-18
Buzzer_ON
R4
4.7K
R51
1K
BZ1
BUZZER
VDRW
B
E
C
Q4
DTC143EKA
(1)
