One of my adsense account got six months ban on december 2013 and all the connected youtube a/c's monetization got disabled. My main adsense youtube a/c didn't get affected on suspension, as the suspension is because of another linked youtube a/c and all gone! Its important not to do any BH on main adsense youtube a/c.
After six months, couldn't monetize the old youtube a/c's, also, I make sure all connected old youtube a/c's are in good standing, if, any a/c is in red, I delete the whole a/c (not just the video) but when I added new youtube a/c's link to my adsense, then the ads are showing, the reports and revenues are generating.
So, it means, once you got six months suspension, all the old youtube a/c's connected to adsense are dead for monetize again. But, you can monetize new youtube a/c's after six months and that is what happened to me.