I've got a Bosch Advanced Rotak 650 (corded electric) that I can't get to start.
I bought it second hand through facebook, so not sure its age, but looks fairly new.
Sellers appear genuine that it worked for them. It's been in a garage over winter, might've got slightly damp but hasn't been standing out in the rain.
Checked the fuse by putting it in a lamp and it works. Have attached the grass box which I thought might have a safety cut-out.
OK, so I assume you live in the UK ? Normally, these electric mowers have a lockout on the startup, whereby you first push and hold a start button, then pull back on a lever or bail bar to start the mower. Once you have started the mower, you can release the start button to continue using the mower. As soon as you release the lever or bail bar, the mower will stop. Assuming you have done all this correctly, if the mower still fails to start, then the problem lies elsewhere.