2.4Troubleshooting Procedures [ 1 ] Control panel related
| Trouble |
| Check: |
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(1) | LCD shows nothing. | • | |
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| • Interfaces between the main PCB, NCU PCB and power supply | |
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| PCB |
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| • LCD | |
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| • | Control panel PCB |
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| • Power supply PCB | |
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| • Main PCB | |
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(2) | Control panel inoperative. | • | |
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| • Interfaces between the main PCB, NCU PCB and power supply | |
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| PCB |
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| • | Control panel PCB |
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| • FPC key | |
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| • Main PCB | |
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[ 2 ] | Telephone related |
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| Trouble |
| Check: |
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(1) | No phone call can be made. | • | FPC key |
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| • | Control panel PCB by using the |
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| code 13. If any defective keys are found, replace them. (Refer |
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| to Chapter V, Section 3.7, "Operational Check of Control Panel |
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| PCB.") |
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| • NCU PCB | |
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| • Main PCB | |
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(2) | Speed dialing or | • | Ordinary dialing function (other than the speed and |
| dialing will not work. |
| dialing) |
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| If it works normally, check the main PCB; if not, refer to item (1) |
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| above. |
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(3) | Speaker silent during | • | Ordinary dialing function (Pick up the handset and press the |
| dialing. |
| numerical keys.) |
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| If it works normally, proceed to the following checks; if not, refer |
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| to item (1) above. |
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(4) | Dial does not switch between | • | Main PCB |
| tone and pulse. |
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(5) | Telephone does not ring. | • | Speaker |
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| • NCU PCB | |
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| • Main PCB | |
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VI - 13
