Fil, Jim We replaced the ADC0 card, ribbon cable, and interface card in the h1oaf0 I/O chassis after the last failure of the ADC/DAC. We also moved the h1oaf0 timing fiber and SFP on the timing fanout from port 1 to port 13. (This causes an error status on the Beckhoff timing MEDM screen, which shouldn't cause problems.) After startup, we noted that the timing status on the IOP model flashed several times, this can be observed in a raw data plot of the H1:FEC-23_STATE_WORD channel for 10 minutes ending at GPS 1162946454. See attached plot. We have not seen this behaviour previously. Present status: h1oaf0 I/O chassis replaced with x1psl0 DTS I/O chassis, but using all ADC/DAC/BIO and interface cards with the exception of ADC0 and interface card, which were replaced with a set from the x1psl0 I/O chassis.