All sprinkler heads have adjustment screws on top. One is for dispersion
area, the other is for rotation adjustment. You just discovered the
rotation adjustment screw.

When the sprinkler is operating, you'll notice a (-) and a (+) sign on top.
When the sprinkler is on one side ( say left) all the way, you turn the
screw to (-) for less or (+) for more spray area. Play with the screw until
you achieve your area of spray you want.

The dry area could be not from water but from drainage.
Dig up the area and determine if the soil underneath for several inches has
enough drainage to allow water and roots to go deep. If not, replace the
soil for abour 10-12 inches with composted soil from a nursery to get the
grass to grow properly.
wrote in message
ups.com...
Hi,
My lawn has a dry spot and I think it is because the pressure to the
water is too high, I see a lot water actually sprayed outside the
lawn. So yesterday I did a "fix", after pull up the head, I see there
is a little screw on the top, I tried unscrew it, not totally, just
want to make it loose. Really I did not know I make it or not because
it is so tight, all I see is the whole head is turned with my
screwdriver together.

The problem is when I tested it, it did not work as I expected: it
is a 90 degree head, but the water come out 360 degree now!

Do you know what might be the problem?

Thanks.