Epson 680Pro Service Manual - Page 41

EPSON Stylus COLOR 680/777/77i

Revision B

Operating Principles

Electrical Circuit Operating Principles

41

Figure 2-16. C383PSB/PSE Board Block Diagram

The C383 PSB/PSE board has the various control circuits to stop voltage output if a

malfunction occurs on the power supply board or the main board while the printer

mechanism is on duty. Following explains each control and protection circuit.

1.

Regardless of the state of the power switch (On or OFF), the voltage is always

applied to the primary side of the power supply board from the moment or at the

state that AC-plug is plugged in. At this time, F1 plays a role of preventing

AC100V from coming into the F1.

L1 also prevents high harmonic wave noise generated in the RC circuit filter

which consists of C1 from going out, and eliminates the noise from outside here.

2.

The AC is full-wave rectified by the diode bridge DB1, and converted to

x

AC in voltage by the smoothing electrolytic capacitor C11.

3.

The pressured up direct current turns Q1 on through the starting resistor R31 and

starts the primary side of the circuit.

4.

When the primary side is On, the energy (current) led by the electromagnetic

induction through the trans (T1) does not flow to the secondary side since the

diode (D51) on the secondary side is installed in the opposite direction.

5.

When the energy which is charged in the trans is reaching the saturated state, the

voltage which makes Q1 on becomes weak gradually. At the point that this voltage

drops at the certain voltage, C13 absorbs the current in the opposite direction and

Q1 is quickly shut off by the resulting sharp drop.

6.

When the primary side is turned off, the energy charged in the T1 is opened

according to the diode(D51) direction which is installed on the secondary side.

Basically, 42 V DC is output by these circuit operations and the number of T1

spiral coil.

7.

+5VDC is generated by pressured down this +42VDC as power supply. IC51

pressures down the +42VDC and generates precise +5VDC by chopping off the

output, forming the standard santooth wave form by the outer RC integration

circuit.

The C383PSB/PSE board has the various control circuits to stop voltage output if a

malfunction occurs on the power supply board or the main board or while the printer

mechanism is on duty. Following explains each control and protection circuit.

+42V Line Constant Voltage Control Circuit:

The output level of the +42V line is monitored by a detection circuit composed of

the seven Zener diodes. This circuit prevents the voltage from dropping for a

constant level of the output voltage.

2

Section	Page
PRODUCT DESCRIPTION	9
1.1 FEATURES	10
1.2 SPECIFICATIONS	11
1.2.1 Physical Specification	11
1.2.2 Printing Specification	11
1.2.3 Paper Feeding	12
1.2.4 Input Data Buffer	12
1.2.5 Electric Specification	12
1.2.6 Environmental Condition	13
1.2.7 Reliability	13
1.2.8 Safety Approvals	13
1.2.9 Acoustic Noise	13
1.2.10 CE Marking	13
1.3 INTERFACE	14
1.3.1 Parallel Interface (Forward Channel)	14
1.3.2 Parallel Interface (Reserve Channel)	17
1.3.3 USB Interface	18
1.3.4 Prevention of Data Transfer Time-out	19
1.3.5 Interface Selection	19
1.3.6 IEEE1284.4 Protocol	19
1.4 OPERATOR CONTROLS	20
1.4.1 Operating Switch	20
1.4.2 Control Panel	20
1.4.2.1 Switches	20
1.4.2.2 Indicators	20
1.4.3 Panel Functions	21
1.4.4 Printer Condition and Panel Status	22
1.4.5 Printer Initialization	22
1.4.6 Errors	23
1.5 PAPER	24
1.5.1 Paper Handling	24
1.5.2 Paper Specification	24
1.5.2.1 Cut Sheet	24
1.5.2.2 Transparency, Glossy Paper	24
1.5.2.3 Envelope	24
1.5.2.4 Index Card	25
1.5.3 Printing Area	26
1.5.3.1 Cut Sheet	26
1.5.3.2 Envelopes	27
1.6 INK CARTRIDGE	28
1.6.1 Black Ink Cartridge	28
1.6.2 Color Ink Cartridge	28
Operating Principles	29
2.1 Overview	30
2.1.1 Printer Mechanism	30
2.1.2 Printhead	31
2.1.2.1 Printing Process	32
2.1.2.2 Printing Method	32
2.1.3 Carriage Mechanism	33
2.1.4 Paper Feeding Mechanism	34
2.1.5 Paper Loading Mechanism (ASF Unit)	35
2.1.6 Ink System Mechanism	38
2.1.6.1 Pump Unit & Wiper mechanism	38
2.1.6.2 Capping Mechanism	39
2.2 Electrical Circuit Operating Principles	40
2.2.1 C383 PSB/PSE board	40
2.2.2 C383 MAIN Board	43
2.2.2.1 Main elements	44
2.2.2.2 Printhead Driver Circuit	45
2.2.2.3 PF Motor (PF/ PUMP/ ASF Motor) Driver Circuit	46
2.2.2.4 CR Motor Driver Circuit	46
2.2.2.5 Reset Circuit	47
2.2.2.6 EEPROM Control Circuit	47
2.2.2.7 Sensor Circuit	48
Troubleshooting	49
3.1 Overview	50
3.2 Troubleshooting with LED Error Indications	51
Disassembly and Assembly	61
4.1 Overview	62
4.1.1 Precautions	62
4.1.2 Tools	63
4.1.3 Work Completion Check	64
4.2 Disassembly	65
4.2.1 Housing removal	66
4.2.2 Operation Panel removal	67
4.2.3 Printhead removal	68
4.2.4 CR motor removal	71
4.2.5 Waste drain ink pad unit removal	73
4.2.6 Circuit board removal	75
4.2.7 LD Roller removal	79
4.2.8 HP/PE Sensor removal	83
4.2.9 Ink system unit removal (Cap & Pump unit )	85
4.2.10 Paper Eject Roller removal	87
4.2.11 PF motor removal	89
4.2.12 CR unit removal	91
4.2.13 Paper feed roller removal	94
4.2.14 Disassembling ASF frame unit	97
Adjustment	100
5.1 Overview	101
5.1.1 Required Adjustment	101
5.1.2 Adjustment Program feature	102
5.1.3 Adjustment Program Installation Procedure	103
5.1.4 Adjustment Program Initial Setting menu	103
5.1.5 Head ID Input	103
5.1.6 Bi-D Adjustment	105
5.1.7 USB ID input	107
5.1.8 Head Cleaning Operation	109
5.1.9 Initial Ink Charge Operation	110
5.1.10 Refurbishment for DOA	111
5.1.11 Protection Counter Check/Reset	112
5.1.12 Check pattern printing	114
5.1.13 EEPROM check function	115
5.1.14 CSIC Information	116
Maintenance	117
6.1 Overview	118
6.1.1 Cleaning	118
6.1.2 Service Maintenance	119
6.1.3 Lubrication	119
Appendix	123
7.1 Connector Summary	124
7.1.1 Major Component Unit	124
7.1.2 EEPROM Address Map	127
7.2 Component Layout	131
7.3 Exploded Diagram	133
7.4 Parts List	138

Epson 680Pro Service Manual - Page 41

EPSON Stylus COLOR 680/777/77i, Revision B, Operating Principles

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