Panasonic KX-MB263RU / KX-MB263UA (serv.man7) Service Manual ▷ View online
53
KX-MB263RU-B/KX-MB263UA-B
6.15. Main Board Section
3.3V Power Supply descriptions
• IC800 decreases the output voltage when Pch FET installed chopper amplifier type switching regulator produces 2.3A min or
over at the output voltage.
Oscillation frequency is set at approximately 500kHz.
Oscillation frequency is set at approximately 500kHz.
• Q801,Q800,R806,D802,R807,R809,C814,R808 are UVLO (Under Voltage Lock Out) circuit.
Q801 turns on when the in-out voltage is 17V or less and EN terminal becomes low so that IC800's operation is stopped.
• D801 controls no to be a over voltage at 3.3V output when ICs including IC302 break down.
1.2V Power Supply descriptions
20
102
66
67
30
1E
114
9
09
21
100
64
68
29
1D
115
9
09
22
97
61
69
28
1C
116
9
09
23
95
5F
70
27
1B
117
8
08
24
93
5D
71
27
1B
118
8
08
25
91
5B
72
26
1A
119
8
08
26
88
58
73
25
19
120
8
08
Temperature
[C
°]
AD value
HEX reading
Temperature
[C
°]
AD value
HEX reading
Temperature
[C
°]
AD value
HEX reading
54
KX-MB263RU-B/KX-MB263UA-B
DC-DC Main Board Supply
55
KX-MB263RU-B/KX-MB263UA-B
6.16. POWER SUPPLY BOARD SECTION
The power supply board circuit generates +7V and +24Vdc. It also supplies
AC voltage to the halogen heat lamp in the fuser unit.
The power supply board uses the switching regulator method.
AC voltage to the halogen heat lamp in the fuser unit.
The power supply board uses the switching regulator method.
[Input Circuit]
The input current goes into the input rectifier circuit through the filter circuit.
The filter circuit decreases the noise voltage and the noise electric field strength.
The filter circuit decreases the noise voltage and the noise electric field strength.
[Rectifier Circuit]
The input circuit is rectified by D10 to D13 and charge C5 to make DC voltage.
Then it supplies power to the converter circuit.
Then it supplies power to the converter circuit.
[Kick-on Voltage Circuit]
Bias is applied to the Q1 gate via this circuit when the AC power is turned on and Q1 begins operating.
[Over Current Limiter (O.C.L)]
The highest drain current of Q1 is limited by a limit current circuit. The 24V output is limited by this circuit.
[Over Voltage Circuit]
If the 24V output increases because the error detecting circuit or control circuit is broken, Control circuit will recognize this signal
and output becomes 0V. D104 and D503 also prevent over voltage.
and output becomes 0V. D104 and D503 also prevent over voltage.
Dummy load method (to quickly check the power supply output)
Refer to POWER SUPPLY BOARD SECTION (P.124).
Input
Circuit
Circuit
AC
Input
Input
C5
G
H
24V
Kick-on
Voltage
Circuit
Voltage
Circuit
E
F
7V
HTRCTL
GND
Control
Circuit
Circuit
R4
R3
R2
Converter
Circuit
Circuit
C
D
Rectifier
Circuit
Circuit
A
B
+
Error Detecting
Circuit
Circuit
O.C.L
Q1
A-B Voltage Wave Form
C-D Voltage Wave Form
E-F
G-H Voltage Wave Form
0
0
0
T1
PC1
Triac
SCR51
SCR51
Heat Lamp
Photo Triac
Coupler PC2
Coupler PC2
Block Diagram
+
+
56
KX-MB263RU-B/KX-MB263UA-B
6.17. Mechanical Operation
6.17.1. PRINTING
The main motor gear rotates as shown in figure.
GEAR DRIVE OPC drives each part of fixing and developing.
When paper is fed from the standard cassette, the plunger of solenoid is pulled to drive PICK UP ROLLER (STANDARD), then
the roller starts feeding paper.
When paper is fed manually, first the plunger of solenoid is pulled to stop RESISTANT ROLLER. After a few moments turn off
the solenoid to drive RESISTANT ROLLER, then the roller starts feeding paper.
GEAR DRIVE OPC drives each part of fixing and developing.
When paper is fed from the standard cassette, the plunger of solenoid is pulled to drive PICK UP ROLLER (STANDARD), then
the roller starts feeding paper.
When paper is fed manually, first the plunger of solenoid is pulled to stop RESISTANT ROLLER. After a few moments turn off
the solenoid to drive RESISTANT ROLLER, then the roller starts feeding paper.
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