WTF electrical problem. Help!

[nipper]

Took my 91 V20 cuddy cabin out today and had a real nice day. After the last stop for a swim, I fired her up, idled away from the shallows a bit, hit the throttle, and about 5 seconds later, BAM, everything shut down. I immediately noticed none of the gauges was registering any electric power, went below into the cuddy to the fuse panel, and the fuse panel had blown off where it is attached. I re-attached it, but still now power to anything but the tilt and trim. No fuses had blown. I was just a couple hundred yards from the launch ramp, so I caught a tow from a good samaritan, brought it home, and am now asking for y'all's help in where to start. It is a 4.3 litre Chevy V6 motor. I did try the reset switch on the motor to no avail. I have no power to anything but tilt and trim.