The symptoms of tail heavy are mostly that
the plane suddenly goes the direction you
apply elevator. For example you are flying
along but the plane wants to climb, so you give
it a little down elevator. It still climbs so you
give it a little more down, and suddenly it is
diving sharply. You pull back in shock and
it is suddenly climbing hard. You try to level off
and as soon as you think you can get close to
level it is suddenly diving again.

You continue to do this while also trying to
keep it in sight range. Eventually you loose
enough altitude that the next dive puts it
in the ground.

If this sounds like what you are experiencing
nose weight is the solution.

If what is occurring is more like flying along
and suddenly the plane pitches up, slows down
and then abruptly points down, speeds up,
levels off, climbs up to a point then drops off
again. This is a symptom of the elevator being
stuck full up. It could be caused by binding
of the linkage, electronics failure or by not knowing
that the elevator is NOT what makes the airplane
climb. (It is the wing that does that with the
help of the engine.) Giving "up" elevator only
increases the angle of attack.

As the plane climbs it loses speed and when it
slows down enough it dives regardless of
how you hold the elevator stick. If this is
what you mean by not having elevator control,
you need to read a little more about flight
controls and stalls, or have someone demonstrate
it to you.

Jenny