I have swapped out original Toyota Casset player with a Sony CD Player with removable face plate. I can get the unit to reset but the unit does not seem to turn on.

Any help

You lost your ignition power source. It still has constant power, being that you can reset but not turn the unit on. You need both 12 v constant and an ignition source for the unit to power up. Check your fuses. There should be one for radio either inside the vehicle or under the hood. If that's not it, check for a fuse either on the radio wiring itself, or on the back of the radio. If *that* doesn't work, then you may have a faulty radio.

Or - of course - you didn't wire it up correctly.