Richard, Gerardo, Jim, Dave:

While the IFO was in commissioning we went to Mid-Y to investigate the h1pemmy failure which happened at 03:53 PDT this morning. We found that the IO Chassis was not powered up, but the +24V power supply was running. We found that the fuse in the fuse-units at the top of the DC power supply rack had blown for the +24V line. We replaced the fuse, powered up the IO Chassis and noted the DC power supply was drawing at steady 3.5A as expected. It was then we noticed the AA-Chassis was not on. It has a fuse on the +18V line which had blown. Putting a new fuse in caused a hot electrical odor from the AA-Chassis. The fuse was removed to de-energize the AA.

Initially we left all the systems down (computer and IO Chassis) and returned to the corner station. But with h1pemmy not running, the DAQ EDCU and CONLOG were red on the overview screen. We remotely powered up the h1pemmy computer, which then started the h1ioppemmy and h1pemmy models. Wtith the EPICS IOCs running, this has appeased EDCU and CONLOG. For now the two models have FEC and DAQ errors as they are not actually running, only the epics IOC is running. We will remain in this state until the AA Chassis is runnng again.

A trend of a seismic signal and the front end status shows they both went down at 03:53 PDT Thu 01 oct 2015. We presume the failure of the AA-chassis and the overcurrent of the 18V glitched the 24V line which in turn blew the fuse.