This HV card contains TA77,78,79,Limi004,001,002,003,(#7 is bad), 005,006,007,008. So the channel with zero current, is Lumi004. The ADC of TA 78,79 are pedestals only, so some people might want to look at Lumi signals to see whether they have ADC values. If all missing, this HV chip could have problems.
Figure 1