You're mid-build and the circuit runs AC or the polarity might flip. A standard electrolytic will vent and kill your board. This 4.7µF bipolar cap doesn't care which way the current goes. Two anodes wired in series, rated to 50V, handles up to 30mA ripple. Solder it in either orientation and move on. No polarity guessing, no second attempt
| brand | Jaycar |
| capacitance | 4.7µF |
| voltage_rating | 50V |
| type | Bipolar Electrolytic (RB) |
| ripple_current | 30mA |
| polarity | Non-polarised |
| construction | Two anodes connected in series |