I'd advise you to get a new PSU regardless of any other issues. A bad PSU can take out a lot of components if it dies, as what potentially happened in another thread. invest in a quality psu and then take it from there. It might solve your problems, or it might not, but even if it doesn't solve your problems, it's a good investment.
If that doesn't work, and resetting the cmos doesn't work to fix your boot issue, try taking out all of your ram and putting in 1 stick at a time see if it boots. *try this after you reset the cmos*
if none of those things work, it might be a dead mobo or cpu which could be a direct result of a cheap quality PSU.