My ps3 wont launch apps or games it gets stuck on a black screen

Try resetting the video signal. Press and hold the power until it shuts off. Press and hold it again until you hear two beeps. Im guessing you have tried different HDMI cables and another display. If the resolution that the previous owner has set doesn't work with your TV it will do this.

im positive its disk drive problem try to change it and all apps will works fine

If yours is a CECHA,B or a C model. The RSX processor is known to come loose on different spots on its mount (Sauder points) of the motherboard causing a black screen. If this has happened there is nothing more that can be done other than to Reball the processor. Reball not "reflowed" with the heat gun like most people have been known to do. The processor has to be taken off of the board and the balls on back of the RSX have to be stripped off and replaced. I would advise against what people have been showing on sights as a "reflow" with a heat gun as that tactic will warp your motherboard. Reflow done the right way and lasting way requires the right equipment called a reflow machine.