To test the LED wiring and hardware, write a sketch that just turns all the LEDs on.
Each LED should have a current-limiting resistor in series with it. The important thing about the resistors is their resistance, not their Wattage. The required resistance would depend on how much current the LEDs require.
Thank you for quick response!
I realised i described poorly. I have 4 high intensity white LEDs with 82 ohm resistors (which i have tested and calculated, i think correctly). I will double check the circuit, might have done a stupid mistake in wiring, but i have checked numerous times. Could it be because arduino is not dealing with it properly, the way i structured the code, it cant distribute its power correctly? i am not sure if thats even possible to run into a problem like that, but worth asking as i dont know it.
Thanks