With the Winegard 76cm or GEOSATpro 90cm/1.2m dishes, it is very easy to determine if the reflector is bent or warped without disassembling the dish using a string test.
Using two, three or four strings, stretch them across the reflector's face, rim edge to rim edge at opposing angles. Wrap the string aound the back side of the reflector and tape. If there is a gap between the strings crossing in the middle of the reflector, the reflector is warped and the satellite signals will not be focused into the prime sweet spot where the LNBF opening sits. The strings should lightly touch where they intersect. If the strings do not lightly touch, disassemble the dish and test the reflector on the perfectly flat surface.