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Security & Fire Protection Systems/PC 1500 Alarm System Zone 2 Error Light--AC Fail


QUESTION: Attempted recommended reboot several times by removing plus (red)lead from circuit board followed with reconnect and connect of (new) backup battery--all this after tiring of turning off main circuit breaker as well a couple of times with same result.  Next used my multi-meter to check for (any) voltage between red and black leads of pin 1 and 2 of circuit board--NO voltage level at all....  Tried tracing red voltage wire up from box thru attic to source and it goes back into wall down from attic.  Where should I expect the source to emanate from and is it directly coming out of main breaker box in our garage wall--wire gauge does not appear to be heavy enough to carry full 115 v AC?  What is the AC voltage supposed to be going to the circuit card/system?  Is there a likely culprit, voltage step down/transformer/breaker in between I am missing that could be causing the issue? Our DSC Security Products manual is very limited, has no schematic included showing installation wiring configuration. First time over many years we have ever had this or any other error code.  Thanks

ANSWER: Hello Mark, and thanks for your question.

First, here's a link to the installation manual for your system:

The hookup diagram is near the end.

From your description, you've lost AC power to the control. This is provided by a plug-in transformer. The transformer is 16.5 volt, 40 VA, and these are widely available on the Internet, and perhaps at a Radio Shack or other electronics store.

But you have to find the transformer... They are usually beige in color, about the size of two cigarette packs. It should be plugged into a regular wall outlet, but in rare cases, an electrician may have provided a "hidden" outlet in some out-of-the-way spot like a basement or in a closet. You'll have to trace the wiring as best you can for clues.

Once you find it, be sure to check that the outlet is powered before replacing the transformer. Just plug a known-good lamp into it to test, or use your meter.

I hope that helps!

Best Regards,


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

QUESTION: Mucho thanks!  Found the transformer and it has overheated coloration on both sides.  Checked the duplex plug and it has steady 115 VAC, so it appears transformer has failed.  It has 16.5 VAC 20 VA on secondary.  Having great difficulty finding equivalent replacement on line, including calls to Radio Shack, Frye's, and Home Depot after researching their respective web links.  This transformer was made by Basler Electric, Highland Illinois, but a direct search for this company yields nothing comparable in Class 2 package as this.
How precise is the output voltage of 16.5 VAC and 20 VA current, as I have finally located one transformer on line with 16 VAC and 20 VA output in Class 2 duplex plug in configuration sealed package?  Or do you know of another source for exact replacement if there is no tolerance on the required output?

Hello Mark, here's a link to an online alarm equipment supplier where you can get the exact specs. In terms of those specs, the voltage must be exact, but you can go higher on the VA rating.

If you Google "alarm parts" you can find other online vendors, and check their stock and prices by searching for transformers on their sites.

By the way, the manual for your system specs a 40 VA transformer. You had a 20 VA transformer that over the course of years, was working harder than it should have. More work, more heat... and that's where that discoloration came from. That may or may not have been the ultimate cause of the failure. If you go with a 40 VA, the transformer should run a bit cooler.

Best Regards,


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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.


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