JCM GOLD GP-965 User manual

GP965 SLIP PRINTER
SERVICE MANUAL
JCM GOLD (H.K.) LTD.
JULY, 98

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INDEX
1. OVERVIEW
2. GENERAL PRECAUTIONS
3. REPAIR BY UNIT REPLACEMENT
Table 3-1Main Units of GP-965
Table 3-2 Required Measuring Instruments
Table 3-3 Surface Phenomena for Troubleshooting
3.1 The POWER switch is turned ON but the printer doesn’t operate
3.2 The printer operates but printing is abnormal
3.3 Paper feeding is abnormal
3.4 The control panel doesn’t work properly
4. REPAIR ON THE UNIT LEVEL
4.1 Main Circuit Board Unit
4.2 Panel SW Circuit Board Unit
4.3 Power Supply Circuit Board Unit
5. Diagram of the Power Supply Circuit
6. Diagram of Main Circuit Board

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1. OVERVIEW
Because of the variety of symptoms that may occur according to the site of the problem, troubleshooting can be quite
difficult. To simplify entry into the actual repair procedures, however, this chapter groups them into the two categories
below:
(1) Repair by unit replacement
(2) Repair of the units
First, follow the procedures for repair by unit replacement to isolate the defective element within that unit. For all
information on the troubleshooting procedures for the printer mechanism, refer to the separate “GP-965 Technical
Manual.”
2. GENERAL PRECAUTIONS
Please pay attention to the following notes for the operation of GP-965 slip printer.
Power on:
Turn on the power of ECR first, then power on GP-965 slip printer.
Power off:
Turn off the power of GP-965 slip printer first, then power off the ECR.
Operation message:
While operating the GP-965 slip printer, if GP-965 slip printer has paper, but ECR display the message that GP-965 slip
printer has no paper, please turn off the power of GP-965 slip printer, then turn on it again.
3. REPAIR BY UNIT REPLACEMENT
This section is organized on the basis of the surface phenomena that accompany the occurrence of a problem, allowing you
to distinguish between troubles on a unit basis. Table 3-1 lists the main units of this printer, and Table 3-2 lists the
instruments you will require. Table 3-3 lists each surface phenomena and the page of this chapter the corresponding
flowchart can be found.

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Table 3-1 Main Units of GP-965
Name Unit No.
Main Circuit Board Refer to the GP-965
Power Supply Board Refer to the GP-965 PS
Panel SW Circuit Board
M-290 Printer Mechanism Part Pricing List
Table 3-2 Required Measuring Instruments
Designation Standard
Tester DC voltage and resistance
Oscilloscope Equipped with 50-MHz storage
Table 3-3 Surface Phenomena for Troubleshooting
Surface Phenomena Description Page
The POWER switch is
turned ON, but the printer
doesn’t operate.
lThe POWER LED on the control
panel doesn’t light.
lThe POWER LED lights, but the
printer isn’t initialized.
5
The printer prints, but
printed results are poor.
lNo printing is performed.
lPrinting is faint.
lDots are missing.
7
Paper feeding is abnormal. lThe paper is not fed at all.
lPaper feeding is irregular and
printing is uneven.
8
The control panel doesn’t
work properly.
lThe REVERSE or RELEASE
switch doesn’t work. 9

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3.1 The POWER switch is turned ON, but the printer doesn’t operate
lCHECK POWER SUPPLY
Y
N
N
Y
N
Y
N
Y
Y
N
NY
START
Is the +24VDC
output voltage
normal?
END
Is the AC
input voltage
normal?
Check the contact of
connector and AC switch
Is the FUSE
normal?
Check the TOP224 regulator
Trouble
remedied?
END
Replace the power
supply board
Trouble remedied?
END
Replace the FUSE
Trouble
remedied?

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lCHECK MAIN CIRCUIT BOARD
Y
N
N
Y
Y
N
Y
N
N Y
START
Input +24VDC to CN1.Then
POWER LED lights?
Is the +5V voltage normal?
Check the contact of all connectors
Trouble remedied?
Replace the main circuit board
Trouble remedied?
Replace the printer mechanism
Trouble remedied?
END

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3.2 The printer operates but printing is abnormal
Y
N
N
Y
Y
N
Y
N
Y
N
START
Start the self test
Is the printing
faint or missing
dots?
Any printing is
performed?
Check the contact of connector CN5
Trouble remedied?
Replace the main circuit board
Trouble remedied?
Replace the printer mechanism
END
Wipe the print head with
alcohol
Trouble
remedied?
END

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3.3 Paper feeding is abnormal
N
Y
N
Y
Y
N
N
Y
START
Are CN5 and the M-
290 connector in
proper contact?
Replace the main circuit board
Trouble
remedied?
Replace the printer mechanism
Trouble
remedied?
END
END
Correct the contact
Trouble
remedied?

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3.4 The control panel doesn’t work properly
N
Y
N
Y
Y
N
START
Connector CN3
contact is
normal?
Replace the panel SW circuit
board
Trouble
remedied?
Replace the main board
END
Correct the contact
Trouble
remedied?
END

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4 REPAIR ON THE UNIT LEVEL
4.1 Main Circuit Board Unit
PHENO-
MENON DETAIL CAUSE CHECK REPAIR- METHOD
Abnormal +5V power
supply Faulty zener diode ZD6,diodes D1,D3,
and regulator
U2(LM2575T-5.0)
Check the +5V supply
voltage in pin4 of U2 Replace ZD6, D1, D3 and/or U2
Abnormal oscillator
circuit in CPU Faulty oscillator X1 Check if the oscillator is oscillating properly Replace X1
Abnormal section of
program ROM Faulty U15(CPU) and U5 Check the pin39 output of the CPU and pin10 output
of the U5
Replace the U15
and/or U5
Abnormal RAM
selection Faulty U8, U12 and/or the U15(CPU) Check the pin1 output of the CPU, pin3 and pin11
of U8, and pin3 of U12
Replace U8, U12
and/or the CPU
Abnormal drive of DC
motor Faulty TR3, U10 and CPU Check the pin25 output of the CPU and pin9 output of
U10. Check if TR3 is
normal.
Replace the CPU,
U10 and/or TR3
Abnormal BOF sensor
operation Faulty U15(CPU) Check the pin37 output of the CPU Replace the CPU
Abnormal TOF sensor
operation Faulty U15(CPU) Check the pin36 output of the CPU Replace the CPU
Abnormal ROM Abnormal U7 Replace U7
Abnormal RAM Abnormal U11 Replace U11
The printer
doesn’t
operate at all
Abnormal CPU Faulty U15(CPU) Check pin42(ALE signal)
of the CPU Replace the CPU
Faulty
carriage
operation
The carriage doesn’t
work at all Abnormal +24V supply voltage Check +24V voltage in pin1, 2, 3, 4 of CN5 Check power supply
No printing is
performed Faulty charge pulse circuit Check the collector TR3 output, pin25 output of U15
and pin9 output of U10
Replace U10, U15
and/or TR3
Abnormal
printing (by
the self test) Certain dots are never
printed Faulty transistor TR5, U8 and/or U14 Check the output of TR5, pin8 output of U8, pin13
output of U14
Replace the TR5,
U8 and/or U14
Abnormal
release
operation
No paper release is
performed Faulty CPU, TR8 and/or D27 Check pin23 output of CPU and TR8. Check if D27 is
normal
Replace the CPU,
TR8 and/or D27
Paper feeding
is abnormal No paper feeding is performed Faulty CPU, TR6, TR7, U13 and D25 Check pin24, 44, 45, 46, 47 output of the CPU, and
TR6 and TR7. Check if the
D25 is normal
Replace the CPU,
TR6, TR7, D25
and/or U13
The panel
switches
don’t operate
properly
Faulty U16 Check pin7 and pin9 of
U16 Replace U16

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Abnormal
driver/receiver in serial
port
Faulty U4 Check the signals at
pin7~14 of U4 Replace U4The wrong characters
are printed Abnormal
driver/receiver in
parallel port
Faulty U5 Check the signals at pin1~9
of U5 Replace U5
4.2 Panel SW Circuit Board Unit
PHENOMENON DETAIL CAUSE CHECK REPAIR METHOD
Faulty switches Check the switch Replace the switchesThe panel switches don’t
operate properly Broken cable Check the cable Replace the cable
Faulty switches Check the switch Replace the switchesAbnormal release
operation No paper release is performed Broken cable Check the cable Replace the cable
Faulty switches Check the switch Replace the switchesPaper reverse is
abnormal No paper reverse isn’t performed Broken cable Check the cable Replace the cable
Power LED doesn’t
light Printing is normal
Faulty LED Check the LED Replace the LED
4.3 Power Supply Circuit Board Unit
PHENOMENON DETAIL CAUSE CHECK REPAIR METHOD
CN101 (AC input)
and CN102 (DC
output) aren’t
connect good
Check CN101 and
CN102 Connect CN101 and CN102 well
F101 (FUSE) is
broken, and/or
faulty RT101
Check the FUSE and
RT101 Replace the FUSE and/or RT101
Faulty diodes
D101, D102 and
D103
Check diodes D101,
D102 and D103 Replace diodes D101, D102 and/or D103
Faulty U101 Check U101 Replace U101
Faulty U102 Check U102 Replace U102
Power LED doesn’t
light Printer doesn’t operate
Faulty Q101
(TOP224) Check Q101 Replace Q101