solver trouble



Hello All,

I am trying to use maxima to solve for y with the following code:

    Ucr(y):=offset+c1[21]+2*sum(realpart(c1[m+20])*cos(2*3.14*(m-1)*y/dp) -
imagpart(c1[m+20])*sin(2*3.14*(m-1)*y/dp),m,2,nmax+1);

     solve(Ucr(y)-40.985=0,y);

c1 is a list and there are numerical values for offset, and dp.

When I try this i either get an error about adjusting 'linel' or a big
block of nonsensical numbers and no value for y. Adjusting 'linel' only
affects the display. I am not sure exactly what to do. IS there a way I can
give 'solve' a range and to have it search for solutions in that range?

Thanks,
Ben