The FAQ post about post ban mentions that it's possible to post one more question after a six-months waiting period and if the question is good enough, the question ban can be lifted:
If you're unable to improve your existing questions, you'll get the chance to ask one new one 6 months after your last question. If that question is positively received, you may be able to continue asking questions; if not, then the ban will be reinstated.
What is positively received in this context? Is it enough if the question has a zero score and is not closed? Or does it have to have a positive score?
How long does the system wait after posting this new question to evaluate this criteria and possibly lift (or reinstate) the question ban?