Fault Finding; All Telephones Dead; One Telephone Dead; All Telephones Live, But No Dial Tone - Marine microSwitch Technical Manual

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4.3

Fault Finding

The following information is intended to assist with fault finding to module level only. All
MicroSwitch exchanges and modules are fully tested before despatch from the factory.
Should problems be experienced when the exchange is first powered up, you are advised to
carefully check all wiring and the presence of power supplies before proceeding. No module
should be removed from, or inserted into the MicroSwitch exchange whilst the exchange is
powered up. The MicroSwitch exchange contains static sensitive devices and special anti-
static precautions should be exercised when handling the MicroSwitch modules.
4.3.1

All Telephones Dead

If no sound can be heard at the telephone ear piece when you blow into the mouth piece, then
the telephone is considered to be dead. If all telephones exhibit this fault :
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Check that the MicroSwitch exchange is powered up and that the power
indicators on the front of the PSU. If they are not lit, check the fuses. If the fuses
are correct replace the Power card.
4.3.2

One Telephone Dead

If the symptoms are as described above for one telephone only :
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Check the wiring to the telephone. Check the operation of the telephone on
another extension. Replace as necessary.
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Check that the appropriate LED on the front of the switch card lights when the
telephone is 'off-hook'. If it does not, replace the Switch module.
4.3.3

All Telephones Live, But No Dial Tone

Sound can be heard at the ear piece when you blow into the mouth piece, but no dial tones
can be heard when calling another telephone. If all telephones exhibit this fault :

Check that the MicroSwitch exchange is powered up and that the power
indicators are lit on the front of the PSU. If they are not lit, check the fuses. If the
fuses are correct replace the Power card.
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Check the in/out of service telephones. Refer to the factory set configurations list.
If you have re-programmed the MicroSwitch exchange, print out the current
configuration.
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Reset the MicroSwitch by connecting pins 7 and 8 together on the two part orange
RS232 connector.
÷
If the programming appears correct, replace the Processor card, but note that any
special programming for your exchange will need to be repeated.
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