EPSON Stylus COLOR 900/900N
Chapter 3 Troubleshooting
77
Table 3-18.
Isolating the Problem on the Power Supply Board (continued)
Table 3-19.
Isolating the Problem on the Power Supply Board (continued)
Step
Problem
Solution
7
Is the main switching
FET (Q1) defective?
Check the electrical continuity of the switching
FET by trying the four patterns below. Be sure to
pay attention to the polarity. If the main switching
FET is good, the results should be as shown under
the figure.
Step 1: Off, Step 2: On, Step 3: Off, Step 4: Off
8
Is an NPN transistor
defective?
Check the electrical continuity of Q2 and Q54 on
the C265 PSB/PSE board using the four patterns
below. Be sure to pay attention to the polarity. If
the transistor is good, the results should be as
shown under the figure.
Step 1: On, Step 2: Off, Step 3: Off, Step 4: On
S t e p . 1
G
D
S
+
-
S t e p . 2
G
D
S
+
-
S t e p . 3
G
D
+
-
S t e p . 4
G
D
+
-
S t e p . 1
+
+
S t e p . 2
+
+
-
B
E
C
N P N T r
S t e p . 3
S t e p . 4
B
C
E
B
C
E
B
C
E
B
C
E
-
-
-
Step
Problem
Solution
9
Is a PNP transistor
defective?
Check the electrical continuity of Q3 and Q53 on
the C265 PSB/PSE board using the four patterns
below. Be sure to pay attention to the polarity. If
the transistor is good, the results should be as
shown under the figure.
Step 1: Off, Step 2: On, Step 3: Off, Step 4: On
10
Is the +5 V regulator
(IC51) defective?
Using an oscilloscope, check the output waveform
at Pin 5 of IC51. The output waveform should be
as shown below.
S t e p . 1
+
-
+
-
S t e p . 2
+
-
+
-
B
E
C
P N P T r
S t e p . 3
S t e p . 4
E
B
C
E
B
C
E
B
C
E
B
C
P i n 5 ( O S C )
G N D
I C 5 1
O s c i l l a t i o n w a v e f o r m
Summary of Contents for 900N
Page 1: ...EPSONStylusCOLOR900 900N Color ink jet printer TM SC900 N 6 59 0 18 ...
Page 8: ... 37 5 PRODUCTDESCRIPTION ...
Page 37: ... 37 5 OPERATINGPRINCIPLES ...
Page 67: ... 37 5 TROUBLESHOOTING ...
Page 89: ... 37 5 DISASSEMBLYANDASSEMBLY ...
Page 121: ... 37 5 ADJUSTMENTS ...
Page 156: ... 37 5 MAINTENANCE ...
Page 169: ... 37 5 APPENDIX ...
Page 179: ...EPSON Stylus COLOR 900 900N Chapter 7 Appendix 176 Figure 7 3 C265 Main Board Soldering side ...
Page 181: ...EPSON Stylus COLOR 900 900N Chapter 7 Appendix 178 Figure 7 6 C265 PNL Board ...
Page 195: ...06 03 01 02 for S E ASIA 03 03 05 03 04 EPSON STYLUS COLOR 900 No 7 10056 Rev 01 ...
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