2009 MacBook no longer boots after SSD upgrade
Take out the SSD and put in the original hard drive, see if it will work then. If not, take it to an Apple Store. They will run a diagnostic to see what's wrong. Don't tell them you've opened it yourself and don't leave in the SSD otherwise they're gonna tell you the warranty is voided. BTW in case you're a smoker, I would also recommend cleaning the inside.