Hi,
Do you have a slightly flat 9V battery? (voltage below 8.5V. Although to be honest a brand new one is probably safe too - I doubt a full 9V would harm it especially as it will drop way below under load)
Try connecting it across the centre contact and the outer edge (threads) of the head. Observe correct polarity carefully and don't accidentally touch any of the other pads on the driver board.
It wont provide enough power to run the light properly but it might be able to prove if the board works or not when power is applied directly to it. Ideally you'd do a test like this using an adjustable bench power supply though (if you get into flashlight modding, invest in one)
Kind regards