Scantronic 9651 Aux Low Voltage

23 Sep 2020
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United Kingdom
Hi Brains of the interweb.

I have a Scantronic 9651, that suddenly is showing 2.3volt on the aux terminals. I've checked the battery input leads and they are reading 12v and I have also tried a brand new battery which for a small time gave 7-9volt reading on the aux terminals before dropping back to 2.3v.

The fuses look fine and I guess if either was blown there would be no current? I have no sensors wired in, only the keypad.

There is also fault reading on the panel aux DC Fail.

Any insight would be great!
Last edited:
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Post a picture of pcb and what s connected to it ....does it have a speaker fitted and is it still wired in , if so remove it and check voltage , does it have an external bell wired in ? If so again remove it and check voltage
Hi there, I only have the keypad connected. Note, I was using this panel for nearly 1 year to power the small 12volt dc konnected alarm panel you see on the bottom of the cabinet. It is currently disconnected and not getting enough power from the AUX terminals now. All of the sensors are wired into the konnected panel and it connects with wifi to my iot hub. Anyhow that is not plugged in and was functioning up until yesterday when it lost power.

I am only using the panel now as a dc power supply and always have the keypad in installer mode. I am confused how its only outputting 2.3v. Is there some failsafe mode? The fuses appear to be intact.

I have taken the voltage of both batteries I have tried, they both read 13v approx, same as the battery connector terminals also read 13v approx. But aux is reading 2.3v

You have something connected to the speaker ! ...the + and LS ....TAKE This out and check aux volts
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Also what current does the Konnected unit require ? Looking on website it comes with a 2amp psu ....the 9651 only provides 1amp max may have damaged the control panel ?
Hi existing internal sounder was still connected to the speaker terminals which I've now removed. Also now seems that the DC Aux fail message is gone but the voltage on AUX is still in the 2-3volt range.

I cant understand why the Konnected panel would need much more current that what the panel already supplied, afterall the same sensors were wired directly to the panel, only difference is the small NodeMCU brain/wifi which maybe draw some extra current.

Here is the directions on the Konnected panel power options. I could use a DC power adapter as it works or replace the internals of the alarm panel with a AC/DC 12v inverter.
Any other things that could cause this? I'm not an electrician but my understanding is if the konnected board had tried to draw more than 1amp then the AUX fuse would have blown and prevented any damage to the board?
I’ve seen panels with faulty batteries damage an alarm pcb without blowing the battery fuse ...something pulling more than the maximum current can damage components on the pcb ...
Ok, interesting. Thanks for your help.

I guess I could remove the alarm panel and reuse the AC power and mount this AC/DC Power Supply to provide a 12V amp supply to the konnected board inside the same cabinet. Would 3A be too high for the motion sensors and the typical wiring? Link to the PSU is below.|&CMP=KNC-GUK-GEN-SKU-MDC-Test111

Are there any safer options to reuse this AC connection to DC? I cant turn the thing off at the consumer unit as my ring doorbell is powered off the same 6amp circuit.

Your help is really appreciated
Total I think is 1amp that includes aux ,bell , keypad and speaker drive...higher psu ok it will only take what it needs anyway ...

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