DSC 1575 : trouble light for AC power stays on

[gjertsen]

I've been troubleshooting this DSC 1575 system for my wife's house.
The system had been dead for quite a while when I looked at it, so I
replaced the battery first. Then I replaced the transformer (no
continuity on the output terminals) and the system powered up
OK.

I had to reset the system clock to turn off one trouble code.
The problem is that the trouble light stays on and indicates
another trouble code: AC power loss (get a 2 after "* 2" sequence).
I'm trying to figure out if there is a reset/clear that I need to do,
or if perhaps there are other issues here. I removed the battery
temporarily for a quick sanity check and the system was
definitely getting power. Any pointers?

Thanks,

--Rob

 

[R.H.Campbell]

Rob, check the voltage level coming in from the panel transformer at the
actual panel terminals. Sometimes if the AC voltage coming in the home is
too high, the end voltage going in the to panel will end up being too high
(or low) as well, and the panel will give a false "AC trouble" message.
Voltage below 12 v AC or above 20 volts AC at the panel might cause this.

The other possibility is the rectifier on the board has blown and your board
is toast.

A last resort (although I very much doubt it will help) is to hardware
default the panel and reprogram.

There may be other causes but those are a couple of the ones I have
discovered that cause weird AC trouble failures.

R.H.Campbell
Home Security Metal Products
Ottawa, Ontario, Canada
www.homemetal.com

 

[Jon Aichberger]

Sounds like the bridge rectifier to me. i have had a number of dsc panels
show the same problem. a new bridge would cost less than $5 if you want to
replace it yourself.

 

[Peter Sackmann]

Does your replacement transformer have the right voltage and wattage? A 12
VA transformer, for instance, won't do. Also, you may want to measure the
voltage at the input terminals.