I bought this solar/battery powered dummy alarm recently. All I want to work is the flashing LED.

 

I connected the battery (which was not connected) and the LED alternate flash was working for around 1 week, though no longer more.

 

I can only presume that the battery is no longer charging for whatever reason?

 

The device has been left i a sunny window sill until installation.

 

Please can you advise how I can fix this to ensure LED will flash with solar as main power source and battery as back up?

 

Thanks

Edited April 9, 20251 yr by James1985

Does it have a day/night varistor sensor ? It may only flash when its dark to save power during the daytime. Where is the solar panel I cant see it in the picture. The normal (non solar powered) leds with 2 AA batteries normally last a couple of years so long as the day night sensor is out.

Thanks for your quick response - it was flashing during daytime (in light) previously so don't think this is the issue.

 

The solar panels are the 2 x green parts towards the bottom (housed below transculent blue plastic) - I can add another image if needed also.

 

red lead in neg ?

black lead in pos ?

Thanks - I've swapped the the red to pos and black to neg on the bat side - no LED still unfortunately

3 minutes ago, James1985 said:

Thanks - I've swapped the the red to pos and black to neg on the bat side - no LED still unfortunately

Reversing the polarity may have damaged it, it probably at least discharged the battery. Down power completely for 5 mins then power it back up. Or down power it leave it to charge for a while then power it up

Thanks again - so I tried this, the led flashed once and there was a small beep when I reattached the wires as above - but then nothing beyond that.

 

I can try and leave a bit longer to charge and try again.

 

Beyond that if it is damaged by reversed polarity, is there something I can replace to fix this? Or would it be more serious and more of a write-off situation?

 

Thanks

Its likely one of the diodes has blown, sometimes you can tell which one because the diode splits or looks wet, other than that you would have to desolder each one and measure it. Also look closely at the board both sides you may have burnt a track. Burning smell is another big give away that something has blown 

How is it solar powered ?

Thanks - I did power up again had leds for about 2 seconds and then nothing. I will check the above - thanks again