Greetings to the group from a newbie. I wonder if anyone can offer an explanation or suggestion on the issue I am observing below. Gear: Samsung UCCM GPSDO Enclosure ZYT GPSDO 2019 Observations: After 2 years of operation the "Output Lock" fails to lock and illuminate the Lock Light. GPS is locking, and PPS is also pulsing as expected. Recycle fails to initiate an "output lock", Due to a restricted location I am only tracking 5-6 sats on average with a GPS Time antenna in a less than optimal postiion. Note: Previously this issue occasionally appeared and a recycle seemed to initiate a "output lock" after warmup and survey, this no longer brings the output lock on. I have placed a Trimble GPSDO in the same housing/enclosure with expected " Output Lock " engaging after warm up etc, with the same antenna. I have reviewed online material on the Samsung and find this a bit puzzling. Any pointers/suggestions would be appreciated, Dom Laven