I did my PhD in pure mathematics at a university which does not have a good reputation in mathematics. At that time, I did not know that most British universities are quite weak in maths. Apart from that, my PhD advisor is not a great mathematician.
After graduation, all of my applications for a postdoc position failed. My advisor was not helpful in the application process. Could the reason for this be the fact that my PhD has been awarded by a weak institution? Do they consider it as worthless? If so, how can I overcome this problem? A second PhD is not an option for me.
At this point I should mention, that my all of my PhD colleagues (working in the same field as me) who were at strong and famous universities were successful in finding a postdoc position.