No Signal Quality on some frequencies

[fshams]

Recently I've lost signal quality on frequencies which prevents me to pick up some of the Persian channels. I have no quality on the following.

11998 MHz (H) SR20.000
12090 MHz (H) SR20.000
12115 MHz (V) SR22.425
12122 MHz (H) SR20.000
12152 MHz (H) SR20.000
11867 MHz (V) SR22.000

I can successfully pick up Persian channels on frequencies

11929 MHz (V) SR22.000
11838 MHz (V) SR20.765
12058 MHz (H) SR22.000

Not sure if the LNB needs replaced or if there is another issue. I appreciate a reply.

[pictureon]

Looks like the signal is weak. Realigning your dish should take care of the problem.
Do not think the lnb is bad sinc you have signal on both vertcal and horizontal transponders.