<span style="font-family: book antiqua,palatino; font-size: medium;">I was just thinking of a few things you could do before you crack that puppy open:</span>
<span style="font-family: book antiqua,palatino; font-size: medium;">1. Take out the bag, leave the cover open, press the power switch, and then press down on the bag lockout switch. If the motor starts, then your problem is due to the cardboard top of the bag not pressing down on the lockout switch. Try a different bag in that case.</span>
<span style="font-family: book antiqua,palatino; font-size: medium;">2. Put a new plug on the cord. If there's a replacement plug on it already, it doesn't matter, and if the original plug is still there, it wouldn't be a terrible idea to replace it, as its almost 20 years old by now.</span>
<span style="font-family: book antiqua,palatino; font-size: medium;">If it still doesn't run after trying these steps, it'll have to come apart. As Elux89 says above, the Ambassador is extremely easy to work on. If you need help let me know. </span>