Reverse Engineering a LED Light Controller Circuit

[Borillion]

I am trying to reverse engineer the controller circuit for a LED Grow lamp that I use to grow aquarium algae as nutrient export.

Unfortunately it has an unknown controller on it but since I can measure the pin state its not too big of an issue to figure out.

On the input side it takes 5 volts from a USB cable for power, the usb power wall adapter it comes with is rated for 5v 4A; and on the output side there is what I would guess are dual voltages as the LED PCB's they connect to have red, blue and white LEDs.

These shows how the controller functions


PCB Images
Top


Bottom (Mirrored)


Overlay attempt


Measuring Voltages I see that each LED Array that is lit corresponds to L1, L2 or L3 are connected to ground through Q1 and Q2
Blue Array => Black (Vcc) & Red (L2) GND
Red Array => Black  (Vcc) & Green (L3) GND
White Array => Black (Vcc) & White (L1)
Blue & Red Arrays => Black (Vcc) & Green (L3) & Red (L2)

I was hoping others would be willing to act as a sanity check, as I work through this?


I am trying to figure out the connections to and around Q4 and I am a bit confused as to what I am seeing.
Do others of you map this out the same way?


Thanks!