Dave, Sudarshan, Richard

LIGOCAM reported that three microphone at EY were disconnected.

I found last week that these microphone would work as normal when switched from their original channel position to some other channel on the AA chassis so, we restarted the  H1IOPISCEY yesterday to see if the problem was in the DAC. This was an unsuccessful attempt as mentioned in alog 14225.

Today, I injected 3Vpp signal on all the channels using a function generator and found out the following:

Channel 1-16 are working as normal (I happened to switch those microphones to one of these channels during my first attempt).

Channel 17-30 show nothing on the output end of medm screen monitor.

Summary: The problem is with the AA chassis board. Richard has been notified and this AA Chassis will be switched sometime next week.