Recently I tried replacing a fluorescent bulb in my garage after it failed, upon fitting the new light it wouldn't turn on and there is this knob on the side (I have been told it may be something to do with start-up or a choke or something) and I tried pushing that in / turning it but nothing happened - I now realise I perhaps should not have pushed it in but I was just wondering what it actually is? Below is an image of what I am talking about (not my actual light)
While this question is about what this knob is I would also greatly appreciate it if anyone could give any tips into how to get a fluorescent light to work again.
Could I have pushed the component out when I pushed the know and that is why it is no longer working? Or could it be something different all together. I briefly managed to get it back working again the other day but I honestly have no idea what it was that I did...
It is quite inconvenient this not working so I would really like to fix it but I am not an expert or even an amateur when it comes to this light. I am however an electronic engineer student so know my way around a circuit or two so am more than confident in taking it apart and replacing anything - I just don't know what I would need to replace!