EXT zone, the transistor & the collector node

5 exterior LEDs in parallel · one PN2222 switches them all · D6

+5V rail GND rail collector node (where all 5 branches meet the transistor) 220 porch A 220 porch B 220 entry 220 deck 220 balcony Q3 PN2222 C (collector) E → GND B 1kΩ D6 (PWM) ──► base current: +5V → each LED → its 220Ω → collector node → (Q3) → emitter → GND
+5V wire / GND D6 signal LED
The three transistor legs

D6 high → base opens the valve → all 5 LEDs drain through C→E to ground → they light. Leg order on the part (flat face toward you): E · B · C, left→right, collector is the right leg.