Troubleshooting Circuit Board Errors; Power Supply Board (Pws-Power Board); Control Circuit Board (Pba-Main Board) - Epson GT-30000 Service Manual

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3.1.3 Troubleshooting Circuit Board Errors

This section describes the check points for the electrical circuit boards.

3.1.3.1 Power Supply Board (PWS-POWER Board)

Table 3-8. PWS-POWER Board Troubleshooting
Phenomenon
<Abnormal voltage> Check the input voltage for Z7 (SI-3033).
+5VDC is not output. • 5 pin
<Abnormal voltage>
Check the voltage waveform between D-S of 013.
+24 VDC is not output.
<Abnormal voltage> Check the input voltage for Z4 (
+12 VDC is not output. • Input pin
<Abnormal voltage>
Check the voltage waveform between D-S of 012.
+3.3 VDC is not output.

3.1.3.2 Control Circuit Board (PBA-MAIN Board)

Table 3-9. PBA-MAIN Board Troubleshooting
Phenomenon
<No operation at all>
Reset IC is defective.
<No operation at all>
EEPROM access error
<No operation at all>
CPU is defective.
TROUBLESHOOTING
Check Points
µ PC78M12).
Check Points
Check the input/output signal waveforms
for the following pins of the reset IC
connector (IC4):
• Pin 8 (for RESET signal)
• Pin 5 (for +5V input)
• Pin 3 (for WD output)
Check the CPU (IC1) for the ROM access
signal waveforms output from the following
pins:
• Pin 2 (for ROM_CS signal)
• Pin 91 (for RD signal)
Check the CPU (IC1) for the signal
waveform input to the following pin:
• Pin 86 (for EXTAL input)
Table 3-9. PBA-MAIN Board Troubleshooting (continued)
Phenomenon
<”.atal Error”>
Carriage does not stop at the home
position.
<”.atal Error”>
Lamp does not light.
<”.atal Error”>
White standard level is not read
properly.
<”Communication Error”>
Bi-directional I/. or SCSI I/. are
defective.
<Image is read abnormally>
Table 3-10. PBA-CONNECT Board Troubleshooting
Phenomenon
<”.atal Error”>
Motor drive circuit is defective.
Overview
Revision A
Check Points
Check the CPU (IC1) for the signal
waveform input to the following pin:
• Pin 32 (for HPS signal)
Check the output signal waveform and the
+24 V output voltage level at the CPU
connector (IC1):
• Pin 115 (for LAMP signal)
• Pin 5 (for +24V output)
Main cause: ASIC (IC2) is defective.
(Replace PBA-MAIN board.)
Main cause: ASIC (IC3) and ASIC (IC2) are
defective. (Replace PBA-MAIN board.)
Main cause: ASIC (IC2) is defective.
(Replace PBA-MAIN board.)
Check Points
Check the Drive IC (IC1) Phase drive signal
waveform output to the following pin:
• Pin 11 (for CLK signal)
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