MCM-165 was tested 19/20-Oct-99. It failed because the first AMU/ADC chip does not seem to work and 28 other channels seem to be dead.

It is not obvious what is wrong with the first AMU/ADC chips. Both the preamp and AMU spy channels work and their signals look normal. The RAMP and CLK_ENABLE signals are also OK. However, all the channels always retured 3FF (overflow) for all channels, except one channel always returned 3F8.

There are also 28 other channels, which seem to be randomly scattered throughout the MCM, which do not work. In this case, not working means they give the same ADC value for all Vcal inputs. The channels are 33, 37, 53, 57, 78, 79, 84, 85, 90, 91,113, 123, 127, 137, 139, 149, 157, 169, 187, 193, 195, 204, 214, 217, 223, 226, 227, 241. I checked the spy channels on two of these dead channels: 33 and 37. In each case the spy channel was a V=0 on the scope. This is not normal. Usually they are around 1.3 V even with no input signal. This suggests that the problem is bad connections between the preamp and the AMU/ADC's or else bad channels in the preamps.

The results are consitent with the assumption that there are numerous bad connections on this MCM.