Update: I have replaced the chips, Y axis is fine now but the X has the same issue(I guess it wasn't the chip). The signal doesn't seem to get around the driver and I think the optocouplers are the problem. I have bridged pin 2 to pin 7 on the 6n137 Opto and now I have slight twitches. The red led flickers when the jog button is pressed now(it never did) but the motor only makes a slight twitching move and moves maybe 0.5mm :)

Do you think the opto just needs replacing?

Thanks