I have a pre-assembled DIY project I am working on for the sake of practice, and I'm perplexed as to how to power it on. Below is the schematic.
Based on it, VCC is on pin 7 of U2 and GND is on pin 2. However, the U2 component is not a typical IC as it's a board…
I have a 4.5V power source but can't seem to find a way to connect it to this circuit. I tried different combinations of red-black to one of the pads of the board and had no results. I'm a beginner student, so please be wary of that. Attaching circuit pictures from different sides below.
It appears to be the two pads marked + and - next to Q1.
To confirm that, see if there is a copper track (on the underside of the PCB) from the + pad to the non-banded end of D3 diode, just near the connections?