Help? Aimtrack Recoil engages as soon as power plugged in

[Sneetch]

So I am Positive it is something I have done, but unsure how to address issue at the moment and could use some help.

I have followed the Ultimarc PDF on how to mod the aimtrack and everything is working save the solenoid. As soon as power is supplied to the solenoid it engages 'Clacks' and holds until I unplug the power.  This even happens when the gun is not pointed at the screen.

I am using all Ultimarc parts (new PCB v8.15) and a power supply which can provide 36v at 5amp peak (similar/identical to others use/recommend -bought from ebay).  it has an LED to show when plugged in and has a dial to increase/decrease voltage.

My solder points 'appear' to be good, but since the solenoid engages immediately I must have an issue somewhere.   

My attempts to troubleshoot have been:
1) Check connections for loose/bad/incorrect connection
        result:  all seems correct and good....yet, issue described above happens.

2) Leave power supply unplugged and play Mame title
        result:  The gun works as expected as if I never attempted to modify it with recoil.  Which makes me think most of the connections to the trigger PCB are correct/working

3) flip the +/- voltage wires to the power supply
        result:  power supply LED does not come on and solenoid does not engage immediately or when trigger pulled (towards or away from monitor).   

So, where to go from here to resolve the issue?  Before I start attempting to unsolder/solder the connections again I am hoping others have encountered and overcome this issue and can enlighten me.   Any thoughts or guidance would be appreciated.

Thanks!