SYSTEM Test results, - DirecTV DVR

For SYSTEM Test results,, relating to DirecTV DVRs and receivers. just found this out also,after running SYSTEM TEST, (again will have tech due to marrow look at it ) & see why, but any idea,
ran system test

Tuner 1,ok acquired at 88
tuner 2, failed-what is tuner 2, is it another reciever or something in the H20 reciever thank you again, "AA"