It will only damage your components if anything happens to it like shorting out, If it doesnt have the proper protection it could take other things with it when it dies.
I ran my rig ( not my current one ) but a sli GTX 275 off a Generic 750W PSU for about 2 years and it ran fine. I bought a Powercooler 950 Modular PSU which blew up on me but luckily didnt take anything out.
I now have Corsair TX 850W V2 PSU - 80plus Bronze Certified | Ebuyer.com
which is running excellent.
I totally disagree with people saying Generic PSU's are totally unreliable but then would also say if you can afford it, get a decent one.
I work as a Technical advisor and deal with a lot of Samsung Products, Which are total crap. Even the best or most popular make can go wrong and cause problems.