I have a casio CE3700 cash register. The machine locked up. I followed the normal procedures to resolve this, however when I turned the power back on from the socket the machine fails to turn on at all now. No power at all. I replaced the fuse on the plug but still no luck. Please help.

It sounds like there is a good reason for it locking up the first time then. Most commonly it is caused by a printer problem. Most Casio models will run the printer before they turn the display on, so if you can't hear the printer run at turn on, I'd start there. Look for paper jams. make sure the motor can turn freely. If the motor is okay, check the battery. You can experience weird problems if the battery has not been replaced on time. ------------------------------------------------------------------------------------
If anyone needs more information, the manuals are here:
Casio CE-3700 Service (repair) manual: http://the-checkout-tech.com/manuals/TOC/cashregisters/Casio/CE-3700%20and%20CE-3750%20service.TOC.pdf
Casio CE-3700 User and programming manual: http://the-checkout-tech.com/manuals/TOC/cashregisters/Casio/CE-3700%20operators%20and%20programming.TOC.pdf