If you are positive you have the elevation and azimuth properly set, you need to tune your receiver to a known active transponder. The signal strength is only an indicator that you have power to the lnb. If you have zero quality, either you are not set up properly with the mechanical alignment of the dish or you are not tuned to an active transponder. Is this a motorized or fixed setup? What receiver and lnb are you using? You are aiming at a satellite located at 100E. Are you within the footprint of this satellite?
Asiasat5 105.5 degrees East not 100.5, Typo?
More information is needed, otherwise it's just guesses. Is this your first dish alignment? Your Latitude and Longitude? Polar mount (actuator equipped) or Az/El (single satellite) mount? A complete equipment list may also help.
Is the receiver programmed with an active transponder, receivable at your location, on the satellite you're aiming for? Without this, you'll not see a Quality reading. Asia Satellite Telecommunications Co. Ltd. Their footprint maps and channel list don't make it clear as to what transponders are in which footprint. www.dishpointer.com will help in getting the aiming directions. Enter your Lat and Long, select satellite, click GO.