Checking For Power Supply Problems - Epson Stylus Photo 870 Service Manual

EPSON Stylus Photo 870/1270

3.3 Checking for Power Supply Problems

Check for problems in the order listed in Table 3-8 if the printer does
not come on after you plug it in and press the Power button (the
printer does not initialize and the control panel lights do not come on).
You can also use the steps in the table to diagnose intermittent power
problems that occur during operation.
NOTE: Test for possible problems listed in the table below by
trying the actions described under "Solution." If you
have a different problem, proceed to the next step.
Table 3-7. Isolating Problems on the Power
Supply Board
Step Problem
1 Is the cable The power switch for these printers control the
disconnected from secondary side of the power supply. Therefore, if
the control panel? the control panel cable does not transfer signals, the
printer won't operate even if the power supply
board and the main board are properly connected.
Make sure they are connected securely at all points.
2 Is the control panel The power switch for these printers control the
cable disconnected secondary side of the power supply. Therefore, if
from the main the control panel cable does not transfer signals, the
board? printer won't operate even if the power supply
board and the main board are properly connected.
Make sure they are connected securely at all points
3 Does pin 3 on the Check the pin 3 line on the control panel cable using
control panel cable a circuit tester.
have a broken wire?
4 Is CN1 on the power Check that connector CN1 (used to apply AC power
supply board to the primary side on the power supply board) is
disconnected? properly connected.
5 Is CN10 on the Check that connector CN10 (used to apply DC
main board voltage to the main board) is properly connected.
disconnected?
.
Solution
Table 3-7. Isolating Problems on the Power
Supply Board (continued)
Step Problem
6 Has fuse F1 on the Check fuse F1, located beside connector CN1 on
power supply board the power supply board. If it has blown, replace the
blown? fuse. If it continues to blow, either replace the
power supply board or continue with step 7.
7 Is choke coil L1 Check the reverse side of the power supply board
broken? for the proper continuity at the two points shown
below. (Short is good; open is bad.)
8 Is transformer T1 Check if transformer T1 is disconnected between
broken? the poles. Try every combination in each group
shown below.(Short is good; open is bad.).
Chapter 3 Troubleshooting
Solution
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