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Security & Fire Protection Systems/Fire alarm on DSC PC3000 system wont shut off


Hi, we have a security system with a DSC PC3000 control board and LCD600 panel. After a power outage we were unable to stop the verbal fire alarm by entering our master code. We had to unplug the system and disconnect the battery. After replugging the system the fire alarm immediately goes on, we enter the reset codes, the panel indicates there is no trouble but the alarm stays on. Our 4 wire hard wired smoke detectors,(Ge449CST) were almost 20 years old so I changed all 8 smoke detectors with GE541NCSXTs. After plugging system in the fire alarm still goes on and panel indicates no trouble, reseting smoke detectors with *4 does not stop alarm. All new 8 smoke detectors seem to be fine as red light blinks once every 8-9 seconds. We are at loss to figure out how to turn off fire alarm. Thanks

Wow.  It's amazing that you still have a PC-3000 that's functioning.  The technology is almost 30 years old.  :-)

The only thing I can suggest is that you have a look at the common control board.  You'll find it in a largish beige coloured can (usually mounted in an out-of-the-way place, like a closet).  Open the door.  The common control board has a terminal strip that goes right across the bottom of the board.  One of the terminals is identified as "fire".  If this is actually connected, remove the wire from it and secure the end of the wire with a piece of electrical tape.

Depending on the age of your battery, you may have an issue with there being insufficient power to run the keypads properly when you have an alarm condition.  The next thing to do is to remove one side of the siren or bell output (either "+" or "-").  Secure the end of the wire with another piece of electrical tape.

Now plug in your power and battery and try to disarm the system.  If that works, you can turn off the power, unplug the battery, and reconnect your siren leads.  Turn on the system again to make sure the alarm is clear.  Turn off the system and reconnect the "fire" zone.  Turn on the system to see if it's clear.  If it goes back into alarm, something's been wired incorrectly.  You'll have to do some more troubleshooting.  In the mean time, you can go through all of the steps above with the exception of reconnecting the "fire" terminal and still use your system.

If you're still having problems, please don't hesitate to call me at 1-888-340-3473.  

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Frank Kurz


Questions relating to Burglar Alarm and Security Equipment, Fire Alarm and Extinguishment Systems, Access Control, CCTV Systems, Installation, Service, Testing, Verification


30 years installing, servicing, and testing security, access control, extinguishment, and fire alarm systems

Chair of ULC Working Groups for Fire Alarm Testing (CAN/ULC-S536) and Fire Alarm Verification (CAN/ULC-S537), Executive Director of the Fire Protection Technicians Network (

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Associate in Science; Emergency Systems (University of British Columbia); Aircraft Maintenance Technology (BCIT)

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