HL Tiger BB Gun Problem

[Spikey]

Hello All,
Have anyone experienced (and more importantly solved) problems with the Main gun not firing? (Yes, I have turned it on). Moving the remote lever for the gun forwards does absolutely NOTHING! I took the turret off to have a looky, but there was nothing obvious. I put a current from the battery onto the contacts and it whirled into life, so the gun itself works, so no need (?) to replace that. This has left me puzzled as to what to do. Has anyone had similar issues or any ideas as to what I can do?

Whilst I'm here, is it normal for the gun to go up/down by pulling the lever back? It seems a bit slow and a bit of an odd way to do it. I would of thought that pushing the lever forwards and back would move the gun up/down, whilst the little buttons could be used as the gun trigger? Just a thought...
Thanks

-spikey