Electronic Alarms and Home Security Devices - Question on my DSC1550 system

Hope I can use this thread to ask another question on my DSC1550 system. After a power outage over the weekend, the system came back with all 6 zone lights lit (no ready or other lights on) and siren going off every 10 or so seconds. I then removed all power. After that, I tried to reset the system (section [30]) and other suggestion in previous posting in this forum in the hope of re-programming the system. Have not been able to get the ready light to come on. Have tried *2, *8 1500 etc. Any suggestion for me to try to verify if the board is still functioning properly?

Moderator note: Moved you to a new thread.

Thanks to "the_tow-guy" for moving the question to a new thread.
I played some more with the system and found that the master code is still good (after all my tries to reset the system including "power up, *8 0000, remove short, press 91, press 20, 1500 and ##" as suggested in FAQ (though with caution that it may not work for all DSC1550). *2 worked -flashing "trouble" and zone 1 lit (no battery connected). Tried *6[master] [1] to set clock; all light went off; after 3 digits were entered, the buzzer sounded (should have accepted 4 digits).
Punching # sets all the zone lights (only) on.

Any suggestion to test the system to find out if the board needs to be replaced or not would be highly appreciated.
thanks.

I am assuming that you have rounded up an installer manual by websearching the phrase: "DSC PC1550 installer manual".

I am guessing that somehow in all of the is mess your panel has been defaulted (power failures on these older models can scramble the system programming if it is allowed to run on a failing battery). The odds are that your system was originally set to disable the need for resistors.

Go to program *8 [installer code]

go to location 12 by pressing 12.

Turn ON option 5 to disable the resistor requirement.

press #

You will also need to reset your zone types.

Ron, thank you very much for your reply.
Yes, I have been using the "installation manual" for reference. Most likely than not, my system has been locked out (the phone line 10 clicking sounds upon powering up). Trying to reset using section [30] on page 17 or the suggestion in FAQ (shorting reset pins) or using *8 [1500] was futile.
Here are some system behaviors that may help to shed light on whether there might be other problems with my system or not or that getting into the programming mode (getting the installer code and truly resetting the system) is my only problem.
- on power up, after beeping and turning all keypad lights (including ready, armed, bypass, mem, and trouble) ON for a second or so, the keypad settled only on "all zone lights ON" (the rest to OFF).
- After the above, opening a zone (door) would not change the pad's light (still all six zones lit).
- *5 [MC] resulted in flashing mem/bypass/trouble lights and solid lights for zones 1 and 2.
- *6 [MC] resulted in flashing mem/byp/trb (others OFF), [1] resulted in zone 1 lit. After this, four digits were accepted by the keypad (for the "clock" which looked good?).
- *6 [MC] [8] resulted in a long beep (2 secs?) and all lights ON for a couple of seconds (test audibles?) and then flashing mem/byp/trb lights. (seemed to be good?)

Does my system appear to have only the installer code problem (in order to program the zones properly)?
Is there other suggestion to try to reset the board?
If not, is it better to send the board to DSC for "repair" or to simply buy a compatible replacement board from another brand? (I have asked to buy one from DSC and they will not sell directly to me.)

thank you for your help.

Yes, 10 clicks means that the installer lockout was set. You can try the procedure in the FAQ sticky for clearing the installer lockout. Again, it doesn't work on all versions of the PC 1500/1550. If that doesn't work, short of a lucky guess at the installer code, all you can do is replace the motherboard (if you can find a 1550 board) or start from scratch with a new control and keypad(s).

What has happened is that the system seems to have been defaulted, which resets the requirement for end of line resistors back to ON; as well as resetting all of the zones back to the factory default.

Basically, everything _except_ the installer code reset to default (which is how DSC installer lockout works).

Ron,
Knowing the lock out situation, I wonder if I maybe able to take advantage of the existing hardware and "rig" the system to work solely for in-house zone monitoring (as to whether the doors and windows are open or not). By this I mean that if a zone light can indicate that the zone circuit is open or closed, then I can rig a relay system to reverse the NO/NC indications. So, here are my questions.

1. Upon power up now and all doors/windows closed, zones 1 to 6 are ON.
- Are these lights showing whether the zone circuit is open or closed?
- If not, what are these zone lights indicating now?

2. If the lights indeed was indicating whether the zone circuit was open or closed, why was it that when I tried opening a "zone" door, the light for that zone did not go OFF?

3. Anything I can do (via keypad?) to attain the objective of making the zone lights to indicate whether the zone circuit is open or closed?

thanks.
benny

You can install the end of line resistor on each circuit (1000 ohms). It still won't work quite right, because the zone definintions have been reset to the factory default, but, at least the first 5 zones will show open and closed status. Zone 6 defaults to being a fire zone.

This is assuming, of course, that your zone contacts are working properly.

Ron, I appreciate your patience and help. I put in the EOL resistors and can see that the system is functioning according to the default conditions.
I have a question on zone 6 (defaulted to a fire zone) - What is the difference between the electrical circuit expected for a Fire Zone versus the simple window/door non-fire-zone contacts?
(For now, with the EOL in all 6 zones, zone6 light and response seemed to behave the same as the other 5 zones.) I read the schematic for the "typical fire alarm zone connection" in the manual but could not understand what might be the difference and so suspected that I did not understand the diagram completely. From the diagram, it seems that when the smoke detector is powered-up, the relay closes the contacts which transforms the circuit to the panel input from an open to a closed circuit (in series with the EOL) and thus appears to be similar to a non-fire-zone circuit.

Since my zone 6 wiring stayed the same and the zone was wired and defined previously as a non-fire zone, what surprise response can I expect now if I am wrong on this? (my system is not monitored.)

thanks.
benny

Fire zones are normally open circuits, so if yours has been defaulted, a normal NC security circuit will show a fire zone trouble when the zone is open, and go into fire alarm when the zone is closed.

Thanks, Ron. Two questions :
1. I am perplexed with my zone6 : being in default fire mode, it is expecting a normally open circuit. But it was wired and zone-defined previously as "01" (instant, usual door/window stuff). Yet the zone light is now OFF when the circuit (contacts) is closed. With the EOL resistors now in all the circuits, the system can be armed and behaves as expected under the default zone definitions. What do you think may be going on?
2. What may be an economical replacement system for this basic 6 (or 8 to 10 as some zones are in series) zones system? Only local alarm is needed. No external monitoring or communication required.

Truth be told, I'm beginning to doubt that you managed to default the system at all, since the zones didn't seem to default.

In any case any of the major brands will work just fine. My advice to you is to look up the installer manual for any replacement you consider. If you can't make sense of it, don't buy that brand.

Ron, thanks for all your help and advice. Truly appreciate it.
On whether my system was defaulted or not, the "evidence" to consider might be on the effect the EOL resistors had on the system responses after they were installed. The panel lights and operations changed from "useless" to "operational" (under the default conditions described in the manual and except for programming). Sounds weird but I cannot explain it. I will play with it some more in the days to come. Thanks again.

After doing some trials, this is my observation on the function of EOL resistor and my earlier puzzlement with the default fire zone6 with the DSC PC1550 board. I am putting it here just in case it may be helpful to others under similar situation.
The zones' input (board circuitry/program, CPU) under default condition for zones 1 to 5 expects (or requires) about 1 K (the EOL resistance) as the input resistance for a "closed" circuit (or zone protected or door contact closed=zone light OFF). A direct short or open (much higher R than 1 K) is concluded as a breached zone (window/door=open) and the zone light would be turned ON.
As a default fire zone (zone6), the program or input interprets a "high" resistance (even just with the 1K is high enough) as the normal state (protected) and the zone6 light is OFF. A direct short at the zone6 input to the panel would be considered tripping the alarm and the zone light will be ON.
By adding a NC relay in series to zone6 wiring (to translate NC to NO) which I will try next, zone6 should operate as a "normally closed" circuit as with the other 5 zones. Of course, the default timings and other "finer" things in the system would have to stay at their default values unless I can get the installer code somehow.
Thanks again to Ron and others who posted in this forum with helpful and interesting advices and experiences to share.