I am assuming you mean, no power as in the starter wont turn. Not.. no power.. nothing works.. radio/lights/horn.. nada. I have had 2 vehicles fail on me the same way. One was due to dead starter, the other was dry battery. Check fuses/battery first as they are the simplest (keeping in mind that no maintenance batteries do dry up...but I doubt thats your problem.). Other than that... I cant suggest anything helpful cause im not a mechanic and have only owned a Supra for less than a week.
Dont know how much damage you can do running a motor with improper timing. Good luck, thouh!