Help debugging loose contact

[taranraj123]

Hello,

I am an electronics novice (I did some soldering in high school) and looking to get some help from the experts. I recently got a solar power led light that seems to have a loose contact from the solar cell to the PCB controlling the remainder of the circuit. The circuit does have a light sensor which is meant to turn on the LED when the light levels drop. However due to this loose contact the solar cell is essentially disconnected from the remainder of the circuit so the LED is constantly running off the battery instead. Here are some pictures of the circuit in question. I cant really tell where to solder the loose wire to on the board. Any help would be greatly appreciated!

Thanks!

 

[rjenkinsgb]

It looks like it should go on a solder pad labelled B-

The designer marked the wire locations, however the battery negative is in the S- position but from what I can see the battery and solar cell negative both go to the same track, running up to a LED connection.

 

[audioguru]

All my solar garden lights use the solar panel to turn off the LED and begin charging the battery when there is light.
The connections for the solar panel are always labelled S+ and S-.

 

[taranraj123]

Thank you rjenkinsgb and audioguru. Is there a way for me to test the voltage or current across the terminals once connected using a multimeter? Im thinking I could connect it to both S- and B- individual and measure to see which one might do the trick.

 

[audioguru]

On many solar garden lights the S- and B- connect together.

 

[rjenkinsgb]

Im thinking I could connect it to both S- and B- individual and measure to see which one might do the trick.

They are electrically the same, in the same section of copper.

If you want it to look right, move the battery negative to the B- terminal so you can put the solar cell negative in S-, though it makes no difference electrically or functionally.

This shows the copper track more clearly, with the labels from the topside.
All three are the same point, electrically:

 

[taranraj123]

Ah I see. Well that worked great! I was able to solder it to B- and the cell is now charging the battery and the led stays off during the day. Thanks all!