Strange Random noises coming out of Logic X

Hi Guys, I am having a weird issue with Logic X and I'm stumped... any ideas as to whether this is a Logic issue or a iMac one...Firstly I am running Logic X 10.6.2 and a late 2012 iMac with 10.15.7.

The issue I have having is between my Novation Launchkey 49 and Logic, it had been working just fine and then when I went to use the Novation one day, after electing software instrument and loading  brass patch, the track record button lit up and I started getting what I could only describe as helicopter noises, that sound you hear in the movies when a helicopter approaches, and I clicked off the record button and the sound just kept up. 

I tried a different patch I think it was drums and got what sound like just 8th notes of sorta drum noise, that eventually faded out.

Audio MIDI setup shows it's there.

I just tried using the drum kit designer patch and can get sounds on the kit by using the mouse on the drums and using my Roland Octapad...

I somehow don't think Logic is getting a signal as in the MIDI activity display in custom mode, it just bounces between the same note, top and bottom of the display ( 1C-2 127 )

Quit Logic, restarted everything, same result.

Changed both USB cables and USB slots, same result.

Took the keyboard and trued it on my iMac running 10.6 and Logic 9, worked fine.. plugged in my old

M-Audio keyboard, worked fine.....

Went into Prefs to nuke > com.apple,logic10.plist < nothing there.. and no > com.apple.logic.pro <

I use a Roland Octapad as well, so tired that on USB ports and cables, works fine..

Oh, yeah, the pads on the Novation work, as does the pitch wheel, but nothing from any of the actual keys..

Just now, I opened a new session, and chose synth strings from the drop down menu, press record, and sounds like a double tracking, take off record mode, just get one track, 

but now press stop and the noise does actually stop…

About ready to nuke Logic and install fresh version…

Any ideas..??

Thanks Steve