Security & Fire Protection Systems/Napco 850 system


QUESTION: I did everything that you suggested about the system not dialing.  The technician from the security company says that the panel is not dialing, and must be replaced. I have not replaced the panel yet, but noticed another problem. I can't get a solid green light on the keypad even though everthing is closed. The panel shows that zone 3 is the problem. Zone 3 is the motion detector in my living room. What could have gone wrong with the motion detector, and is it something I could troubleshoot and fix?  Would appreciate your comments,  Thanks,     Jerry 11-9-12

ANSWER: I have a few thoughts to add to my previous answer to help you.

First, zone 3 will be termianls 15 and 16 on the bottom terminal strip.

Second, the AUX power will be at terminals 30 and 31 on the right-side  terminal strip.

Finally, the AUX power is protected by a fuse (F2, located above the right-side terminal strip). If that's blown, and the motion detector is powered from AUX power, then that would stop it from working, too.


Hi Jerry, and thanks for the additional information.

In my experience, anytime a technician is working in a panel, there's a chance that something gets broken there. The first place I'd look is to see if a wire has broken off or come loose from a terminal for zone 3.

I don't know whether your motion detector is power by the control or separately... does the motion detector act as usual -- with the LED lighting when it detects motion? If it used to but is not now, the second place I'd look is the AUX power terminals in the control, again to see if a wire broke off or came loose.

I highly doubt that that it's a coincidence that the tech was in the panel and the motion detector decided to fail at the same time.

If you're having your provider replace the panel, they'll find and fix this problem at the same time.

Best Regards,


---------- FOLLOW-UP ----------

QUESTION: Dave:  Thanks for the answer about the motion detector. The detector acts as usual and does detect motion, and I found out that if I shunt the zone that the detector is on, I then get a solid green, which allows me to properly arm my system, etc. But, back to my original problem with the panel, do you know if the problem with the non-communication could be caused by particular components on the panel or by the information that comes from the prom? Perhaps, someone that knows the actual circuitry could replace a bad component or check the contents of the prom, and correct the dialing problem? We are elderly retired aerospace engineers and cannot afford the have the panel and keypads replaced. Estimates are  $750-$1000. Do you know anyone that lives out here in or near Chatsworth, California that has the actual schematic for the panel and would come to my home to repair it?   Thanks for you input,          Jerry  11-10-12

Hi Jerry, I understand the situation that you're in. But I think the odds of finding anyone coming out to your home for a repair at the board level is remote. I'm in Florida, by the way, and although I worked with engineering on some alarm controls and systems in Redondo Beach back in the 80's and 90's,that company no longer exists.

Your equipment dates back to late 1980s, and I doubt that even the manufacturer would be willing to take on a repair of the motherboard.

So your options, as I see them, are these:

First, since you're apparently under contract to a monitoring center or security provider, find out whether there are any penalties involved with canceling that contract.

If you're not bound by contract, you can contact one of the national companies (ADT, ProtectAmerica, etc.) and see about getting a new installation. These companies often run specials that provide a basic system for free or for $99 as a teaser to get a commitment on a monitoring contract, which typically would go for $30-35 a month for three years.

The other option is to use your system as a "local," meaning the only annunciation is from the bell or siren. And since it'd not be monitored any longer, that contract again should be cancelled.

I know these aren't ideal solutions, but that's my thinking based upon what you've told me.

Please feel free to write again if you have additional questions.

Best Regards,


Security & Fire Protection Systems

All Answers

Answers by Expert:

Ask Experts


Dave Neuweiler


The design and application of burglary and fire systems for homes and businesses. Helping alarm owners understand how their system works. Helping to troubleshoot false alarm problems. Questions about monitoring issues.


Over a quarter century in the industry. Experience in installation, service, and monitoring centers. Training manager for a national protective services company; director of education and training for a national trade organization for for alarm dealers.


©2017 All rights reserved.