Issues after power supply failure

I have just replaced my power supply due to failure. I now have 2 issues with my printer, the first is an error message at the bottom of the screen which says ’ no start signal detected - forcing start’. Sometimes the printer will start after a few seconds.
The second problem is the Y axis will not move without a lot of noise or it jumps back and forth. I have checked the stepper motor and set the voltage to 0.55v.
I have not changed any other settings and the printer worked ok before the power supply failure.
Any suggestions would be appreciated.

What did you replace the power supply with?
Was it 15 volts DC?

Yes, it is a velleman 15v DC supply.

Have you checked the voltage from the power supply while disconnected and then when connected?
The control board may have a short.

I checked the power supply when not connected. How would I check it whilst connected?

On the control board (blue connectors)

Yes, I have tried that, there is no problem there. I have also swapped the X axis driver for the Y axis driver but the fault remains on the Y axis.
It seems that my next options are to either replace the motor or the wiring. I am not sure which to do first.