EPSON | Chapter 3 Troubleshooting |
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4. Abnormal Printing
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3.4 Repairing the Power Supply Board
Is the self test | YES |
| Check the data from the |
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| host PC using the hex |
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printed correctly? |
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| dump mode. |
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| YES | Reset the settings | |
| NO | Are any print head | Are the printer | ||
Are all the |
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wires broken? |
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dots printed |
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correctly? |
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The table below provides instructions on how to repair the power supply board assembly. It lists various power supply board problems and provides likely causes, checkpoints, and solutions. To determine whether a component is defective, compare its readings with the correct waveforms, resistances, and other values listed in the table below. Then replace the component if necessary.
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| dots aligned |
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| Perform the |
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| bidirectional alignment. |
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| Check the FFC |
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| the main board |
| Does the printer |
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Check the platen |
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gap/parallelism. (See |
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Chapter 5.) |
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| solved? |
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WARNING
Note:
The OPERATE button on the control panel only turns the secondary power circuit on or off, so the primary circuit is live as long as the printer is connected to an AC power outlet. Before you touch the power supply board or repair it, disconnect the printer from the AC power outlet.
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| YES | Is the FFC |
| Replace the main | |
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| board. |
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| OK? |
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Is the | YES |
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problem |
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solved? |
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NO | END |
| Replace |
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| Are the print |
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| the FFC. | NO | Is the problem | |
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| Are the bottoms of the | head drivers on | |||
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| solved? | ||
| NO | characters missing? |
| the main board |
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| OK? |
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| END |
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| YES |
| Replace the |
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| Is the |
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Replace the |
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| YES | print head |
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print head. |
| Reinstall | problem | and the main |
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| the ribbon | solved? |
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| END | mask. | YES | Replace the |
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| END | print head. | END |
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NO | Is the |
| The computer is the |
| problem |
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| END | source of the | |
| solved? | ||
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| problem. |
| YES |
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| END |
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Use an oscilloscope to check the waveforms in Table
Table
Problem |
| Cause |
| Checkpoint |
| Solution |
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The +35 V and +5 |
| Diode bridge DB1 |
| Measure the DC |
| Replace |
V lines are not |
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output when the |
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| 3 and 4 of DB1. |
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printer is turned |
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on. |
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| Transformer coil |
| Measure the |
| Replace |
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| resistances of the T1 |
| T1. |
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| transformer coils at |
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| pins 12 and 15, 9 and |
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| 11, 7 and 8, and 3 |
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| and 4. |
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