When I changed the bulb on my 2 D light in the bathroom it started flickering. According to your video you need to change the starter. I’ve looked everywhere and can’t find where this is in my light fitting. Can you help?

On most 2D bathroom fittings the “starter” isn’t a separate little can like on old fluorescent strips – it’s usually built into a ballast/gear tray behind the lamp, or the fitting is high‑frequency electronic and actually has no replaceable starter at all. If it’s an older magnetic 2D fitting, the starter is usually a small round plug on the gear tray that twists out; if it’s electronic or LED, flickering normally means a failing control gear/driver or a faulty lamp, not a starter.