There is no life from my power washer.
I have stripped it down and confirmed there is continuity from the plug to the internal switch on the live and neutral.
I've also replaced the large capacitor attached to the motor but this made no difference.
Where do I go from here?
Try bypassing the switch or testing for power after the switch (once switched). I presume you would've done this before deciding to put in another capacitor, but it's worth mentioning. The only other item that comes to mind would be an inline fuse that's blown. Since these things aren't meant to be user serviceable though, if it has one, it's likely soldered-in and may be encapsulated in white opaque plastic (most of what I've seen) as a fire precaution.