M. Pirello, E. Castrellon, F. Clara, R. McCarthy

Per FRS Ticket 6059 and Work Permit 6284 we investigated and repaired the bad channel and restored the unit to operation.

We initially suspected the 5V linear voltage regulator in the Slow Controls Contentrator #2 (S1103451) and pulled it for inspection, but found that its outputs were working correctly.  We replaced the suspect regulator and added a heat sink to help dissipate heat from this regulator.

Upon reinstallation, most of the bad channels were working, and only one set of related channels were not working.  We traced this failure back to a bent pin on the EtherCAT Corner Station Chassis #3 (S1107447).  This pin corresponds with channel DIV40M which Daniel says was not working since its installation.  The Beckhoff Module associated with these signals was behaving poorly, acting like it had an internal short.  We pulled the Chassis #3 and replaced the Beckhoff module #11 on panel #9, with a brand new E1124 Digital IO Module.

After installation other problems with this chassis surfaced so we replaced one of the computer modules and after much testing we were satisfied that the chassis would work when installed.  I attached an image of all blocks green as seen from the CER.