h1iscey frontend server was replaced because of a possible bad PCI slot that was preventing connection to one of the Adnaco PCIe expansion boards in the IO Chassis , see here: https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=80035
The new frontend is running without issue, connected to all four Adnacos.
The new frontend model is Supermicro X11SRL-F, the same as the old frontend.