Question Installation Issues - Not able to Jog

Hi All,
Wonder if you can help a newbie. Have assembled the 840 as per the instructions, greased etc, etc.
I get all the correct lights on the USB connector and the Control Board, Software all installed and licence installed.
My issue is when I load the software and try to manually use the "Jog" function to move the head, nothing happens. It seems the motors only move when I press the AXIS (X,Y or Z -) buttons on the software, Nothing on the + button icons.
Just to be clear, the head does not move around the base,in a smooth motion (as per the videos I have seen) i can just see the grub screws on on the screw thread move very slightly now and then, very slightly, every time I press the button.
I have changed the values (.001, 0.10, 1.00 etc) but with no luck.
Finally, all the wiring has been checked and looks OK.
Any idea??

Are you using uccnc. make sure its set to continuous and not set to step, on the keyboard keypad make sure numlock is off.

Thanks for the reply Jonalm,
I have tried both the Continuous and Step By Step but to no avail.
Have not checked the NumLock, will check that today but I am using the mouse to click the buttons

I think there is a bug with uccnc when you change the jog feed percentage. If you click it fast it stops the motors from continually moving or they just move in tiny increments. It does this with my laptop, it you change the jog feed one click at a time slowly its fine. Rebooting the software is what i have to do if it does that.

I would also make sure the motion controller in the parallel port is fully seated.

Thanks very much.
It seems you were correct about the mouse clicks. I rebooted the PC (rebooted the CNC a few times already), when I used the keyboard and select the continuous all works as (I think) it should.
Now on to the fun stuff