Thank you for the response.
The smoke detectors are all wired as well as powered by 9V batteries - note installed all new 9v batteries. I have 12 smoke detectors. Yes, I did download the manual and have been using it.
Your suggestions are great and I will start turning off the individual zones to isolate the bad smoke detector.
Yes, I have a multimeter but have not used it, also not quite familar on how to use it on the alarm panel.
GAAAAHHHH!!!!
Kevin, STOP!! If it's not already too late,
stop taking things apart and/or buying things you don't need.
The
first thing you do with an alarm system trouble is read the
User Manual/Owner's Manual. If that does't tell you what you need to know, then get the
Installation Manual.
Go to Google or your favorite search engine with the phrase "Caddx NX-8E Installation Manual." You can download it for free, ignore any pay-for-download sites.
First of all: Your zones are numbered, 1 through 8 for on-board zones, higher for expansion zones. You can have hardwired expansion zones, but the fire zone is
usually one of the first 8, and most often zone 8, which supports 2-wire smoke detectors. You need to know whether you have 2-or-4 wire detectors. Each detector except for the last in the series will have either 4 or 8 wires attached: Two in and two out, or 4 in and 4 out. The last one, usually the fartherest from the control panel, will have only 2 or 4 wires connected, and will have an EOLR (End Of Line Resistor) for circuit supervision and possibly a power supervision module if it's a 4-wire detector.
You should have a zone list somewhere but if you don't, read your user's manual and use the keypad to check the zone status of all zones. Undoing wires in the control is kind of overkill and a marvelous opportunity to get wires mixed up.
After you've located the zone number of whatever zone your smoke detector is on, you can take off the wires for that zone loop in the control panel and check it with your multimeter. The most common cause of a fire zone trouble is a loose or severed wire. Your control panel is looking for either 3.3K-ohms or 680 ohms resistance on that zone, depending on whether it has two-wire or 4-wire smoke detectors on it. If it sees a resistance significantly higher than what it's looking for, it will initiate a trouble condition which will not clear until the trouble is corrected. You cannot bypass a fire zone to arm your system.
Couple of other things: Your alarm system smoke detectors
do not have 9V batteries in them. It's a common error to suppose that every detector in the house is part of the alarm system. Your system smokes are powered from the control panel alone, at 12VDC.. Any dectectors with 9V batteries are either stand-alone detectors or 120VAC detectors on your home's line power, not connected to the alarm system. The 120V detectors will have thick electrical wires connected to them whereas your system's detectors will be connected by thin 22 AWG wiring, or 18 AWG at most.
Your system is powered by a 16.5 VAC transformer (wall wart) plugged into an electrical outlet somewhere and this might be a good time to learn where it is if you don't already know. The system's backup battery is to keep the system working when AC power is out, not for memory backup. Memory is in EEPROM. The system could lose all power, AC and battery, and would retain its memory until the next ice age. Unless your battery is five years old, you probably don't need a new one.
Once you find your fine zone, first check to see it's connected tight at the control panel and then check resistance on the loop, the two zone wires. Let me know what you find.
EDIT: I sent you a PM.
