501 has disappearing channels

[acvb]

Got a 501 and a 301 and a superdish 105. Been working great. The 501 started acting up on saturday (has good signal 108 stregnth), keeps pixilizing and loosing channels. But the signal stregnth doesnt drop, just switches back and forth from red to green. So I took the update last night and went from 221 to 222. Its still acting up. Switched cables with the 301. 301 is good but the 501 is still bad. Using a rom2 in the 501. 30 tiers. Any ideas what my 501 problem is???

Also, I have no locks. And I just tried a rom10 with minimal tiers, and the 501 is still acting up. Anyone else with this problem?
Thanks