Karcher 620m pressure washer wont start up or pump
Its the spill valve that stuck under the micro swith, this is quite easy to fix, to take the cover off there are 3 square plastic tabs under the machine, pull these out about 1/2 in that releases the tabs on the case's edge press the case inwards where the tabs were & take cover off, at the hose end the black cover is held by 4 torx screws, take that off and remove the detergent holder, then take the 2 torx screws that hold the micro switch out, pull that away forwards & sideways, take the 4 torx screws off the cylinder head cover & take
the spill valve out, this is probably stuck so take care not to damage it as you try to pull it out, clean the valve & most important clear the bore in the cylinder head, its probably built up a white powderlike aluminium oxide, be careful not to scratch the bore, lubricate the spill-valve & it should now push back with not much resistance, now put it all back together, you could test to see if its workind OK before you fit the top cover, (if it doesn't you haven't cleaned the spill-valve & bore properly)
NOW DO IT AGAIN PROPERLY HA HA HA