Hi when you say electrically dead do you mean that if you turn the inanities on then you get no movement in the needles on the gauges at all and also no lights etc. If so then the main fuse has blown. My 96 +8 also had a fuse in the main feed behind the seat just along from the battery.
If the main fuse and/or the other one has probably gone and you heard a fizzing/short sound coming from behind the dash then probably you either have a short on one of the terminals behind the dash or as others have said the earth is loose. Alternatively Morgans are known to leak water behind the dash and then this can get on the electrical connection and cause poor circuit which may explain the fizzing sound.
I would check all the main power fuses first and then check the dash for a good earth and then look for water traces or poor connections behind the dash. Before you do anything disconnect the earth lead from the battery. You do not want to go poking around and cause another problem or short something out by accident. Once you have found the problem connect back up and try. A multi meter from your local motor factors is invaluable and will only set you back £10-15.
Good luck
