I know this is an old system but looking for help with circuit board components Only getting 8volts to the smoke detector terminals on the board and should be 12 volts. I have tested two of the larger capacitors. The burglar side of the alarms work fine.
If you haven't done so already, remove the wiring from the smoke detector power in the panel and check the voltage at the panel.. There may be a high-resistance short in a device or wiring.
AFAIK Safe House is a private label brand. As already stated, pictures of the circuit board in the panel will help in identifying the manufacturer.
Model is SafeHouse 49-485 Every thing was working fine until I by pass the smoke detector from the kitchen area I may of had a SR moment! I can't remember if I killed the power first. I removed the board and now have the EOL resistor at the board. I have replaced the 3300 and 2200 capacitors witch the old showed good anyway. So when first power on I get a little over 9 volts but not long afterwards volts drops with no load.
I will see about getting photos down loaded.
Last edited by Detour; 11-26-22 at 08:36 AM.
Reason: photos
The four pin device is a bridge rectifier. Converts AC to DC. The caps you replaced filter that DC.
The 16.5vac is applied to the center two terminals and you'll measure +20vdc on + and -.
The LM317T is an adjustable DC regulator.
Pin 1 = voltage set - pin 2 = output - pin 3 = input.
You may see 20-25vdc on the input and probably 12vdc on the output. LM317T spec sheet - pdf
What are you measuring on the battery line with battery connected ?
BE CAREFUL - shorting semiconductors will blast them.
Ok... the voltages on the bridge are fine as that uses a 12vac transformer not the typical 16.5vac.
Not sure the problem testing the regulator.
Takes some smaller and sharp probes.
Where are you getting the 9v.... on # 36 and # 38 ?
Yes on 36 & 38 when I test the detectors on the battery it self
They work fine. When this first happened I did smell an Oder at
the board but see no evidence if that helps what to look for.
What are the input-to-negative voltages on the regulator on battery and on AC power? If the output voltage is OK on AC, you probably have a weak battery; 3-5 years is the life expectancy of a SLA battery.
If output is not OK on AC, look at the drive to Pin 2 of the regulator.
The diode bridge checks ok.
It runs quite warm which is why it's on the heatsink. Runs hotter when battery is older.
That brown stuff is flux leftover after board cleaning. No problem.
Terminal 25 and 26 are the 12vdc ACC terminals and check out ok which means the primary regulator is working.
Red marks are + power
Blue marks are in/trigger
Q7 is the B+ switching transistor for smoke detector power.
Q7 may be bad.
While noodling around I spotted this..... Q9 has exploded.
That funny because Q9 looks nothing like the photo. looks has good as others. Im getting 12.5 at your white 12.5 on your red to ground 6.3 6.5 but! when i push the rest button for fire alarm it sends 12 volt to your red for a few seconds
Removing markings from components was an attempt to keep others from pirating a design. Also done to discourage service. One of the things that made come to dis like board work.
I need to replace 3 interconnected smoke alarms, but I'm unable to identify the breaker to open the circuit to prevent my death. Unfortunately l am working without a guide that maps the breakers to outlets and lighting around the house. All the alarms are removed and the black/white/red strands are connected via twist-connectors. My intent was to read the voltage across the black and white connectors for one of the alarms, and from there start flipping breakers until I isolated the power to that drop, but unfortunately this method did not work, which is a mystery to me. I removed the twist-connectors to expose the black and white wire strands, connected the leads of a multimeter to each strand, but came up with a reading of zero volts. Again, mystery to me. Why am I not able to read 115v across the b/w wires? I would like to avoid flipping the main breaker to the house if I can isolate power to one device.
I have a DSC PC5010 - Power832 system in my second home. It has 4 interior motion sensors wired to Zone 1. That system and those 4 motion sensors were in the home when I bought it 15 years ago and I’ve never had a problem with false alarms until now. In the last month, Zone 1 has triggered 3 false alarms while the home was unoccupied.
I have an EyezOn EVL-2DS board installed so I can remotely look at the logs. For each false alarm I see the same series of log entries for Zone 1:
- Motion Sensors Alarm
- Motion Sensors Alarm Restoral
- Motion Sensors Alarm
- Motion Sensors Alarm Restoral
- Motion Sensors Alarm
- Motion Sensors Alarm Restoral
- Swinger Shutdown
Any ideas on what might be the cause of the problem would be appreciated. For now, I’ve bypassed Zone 1. I’ll be going there on Thanksgiving, but getting troubleshooting ideas in advance is helpful.
11-25-22, 07:03 PM
