Weird Xbox360 Rapid Fire behaviour

[Fitfool]

Hello, i followed this guide https://www.acidmods.com/forum/index.php?topic=25338.0 to create a rapid fire controller, it works, but with a quirk. For some reason, it will not work when i pull the trigger fully down, it will act as if i am holding the trigger down with nod mod whatsoever. I'm not sure why this is happening, but if i had a guess, i may have damaged the transistor when soldering. Any ideas?

Thanks