strange prob with 500 s please halp me

  • hi
    I have a db 500-s,and a sat-pci to see tv on the pc,all is connected to parabola with motor,so if I start the dreambox I don't see,but if I start the sat-pci I see,if I standby the pci-sat no see,and the date of sat searching in too strange,the snr/agg and ber go up and down,but if I start the sat-pci go all normality I have had this problem after a search a new channel !!!!
    before of this all is ok,
    what I do ??
    excuse my bad english,I hope you understand.