HP 88780 tape loading questions

I tried the Overland Data 5622 I bought; it seems to have big troubles. On power-up, "Alert" blinks and it won't load - none of the buttons work. I've temporarily given up on the M4 9914 and exploring the HP 88780. It loads a tape almost always. It catches on the takeup reel, whips into high-speed mode, then Test 0 passes. I've run a few of the most interesting interactive test sequences. NVRAM, timer, DAC, ADC, tach, motor loop, tension limit and sensors, speed encoder, tape sensors, BOT/EOT sensors all OK. Test 1 with a scratch tape fails within test 165 "load tape", followed by "ERR 60". Bitsaver's 7980 manual on page 5-119 (PDF pg. 186) says error 60 is "tracks with gain too low and too high during autocal." Does this mean I need to clear the NVRAM and run the "test 99" calibration? I haven't changed or recorded the NVRAM values yet. Should I bother? Anyone have experience with http://www.comco-inc.com/ ? They're only a few hours away. - John