SMD part "VG73" (SOT-23-6) - Solar lamp circuit

[inse]

If you‘d switch open by closed, I‘d agree.
I assume the switch is a N-MOSFET as there is no base resistor also it needs to conduct in both directions to enable charging and discharging.
Not sure about the sense(?) pin and R20, maybe it detects solar voltage and turns on the switch for better charging?

[thymjan]

I mean the component. In the circuit with operating battery the switch should be closed, is it?

[inse]

For a better understanding:
U3 is measuring  the battery voltage. U5 is a normally opened switch, which only closes if U3 is measuring a certain minimal voltage. If battery voltage is ok, S- and B- are connected.

Sorry for my unclear phrasing.
I assume U5 a N-MOSFET and it should be ON in normal operation and OFF if U3 detects battery undervoltage.

[thymjan]

Here is my first try with KiCad. There are still some wrong components which I didn't find. But KiCad is quite nice for doing this 
And it's a little bit upside down ...


If someone knows tricks to get a better view, let me know!

[inse]

Nicely done for a (Ki-)CAD starter but honestly spoken it’s a waste of time to capture the schematic outside of U3 and U5 as this is only LED control.
So how do you plan to go on from here?
I made my proposals, what is yours?

[thymjan]

Still looking for a replacement for the VG73. Also still awaiting answer from the manufacturer of the lamp.
Maybe it's a sort of DW01 derivative?

[inse]

DW01 appears comparable, why not give it a try.
See if you get one separate or whether desoldering from a cheap BMS is more reasonable.
Bypass the MOSFET for a test if the rest still works.
Btw, you‘re not seriously expecting support from the lamp manufacturer?

[thymjan]

I bypassed the protection circuit by connecting B- with S-. Now the LED is always on. Regardless of whether light falls on the solar module or not.
Whether something happens at the motion detector or not. In winter mode the brightness only gets full when motion appears. I would have expected this is still functional.

It is also not clear to me how charging the battery works.

I think I give up.

[inse]

Oh, what a pity…
How did it get damaged anyway,  batteries installed backwards or hit by lightning?
The charging path is from S+ to K+, via the switch to B+, from B- backwards through U5 to S-