how do i fix my wma510s washing machine?

Before I start I have never heard of a WMA510s so I will assume it to be type error all WMA range of machines were mechanically the same but the electronics were different. Did you mean WMA5 or WMA10? Anyway, to continue:
You have a number of possibilities, it could be the motor or associated wiring connections which would need to be checked with a meter unless you are really lucky and find a connection hanging off. It could be a faulty control module which you would need to remove before you could examine it (there would be a burnt out copper track) but something would have made it blow in the first place. Or you could just have a restriction in your outlet, which could be the sump, the pump or the hose, depending on whether all the water pumps out or if some is left behind. To remove the lid there is a little cap either side at the front of the lid, under these caps are star headed screws, remove them and lift the front of the lid up about an inch then push it backwards, it will now lift off. To take the console panel off you will need to remove the control knob by pulling it off ( first select ‘0’ on the dial so you know where it should be when you replace it) now remove the soap drawer and undo the screws behind it to free the console panel. Pull the left side out about an inch or so and slide it to the right. Now disconnect all the wiring connections. (Try not to touch the control module except by the edges because it could be damaged by static electricity) If the board has blown you will need a new one. The motor is under the machine at the rear so remove the back panel and tilt the machine forward for easier access. The sump pump and filter are accessible from here also. Good Luck!

casper ....http://www.selfix-uk.co.uk
November 2008