Not long ago at a major US airport, the ILS glideslope appeared on the ADI-several MILES early, and was stuck in the center position, indicating on glideslope! There was certainly no computer or other such flag on the ADI. But it never appeared on the HSI glideslope repeater. I hope that Maint. was able to repair it. We rarley keep the same plane in a hub (further delaying the next flight as we preflight the next plane, already delayed inbound due to weather etc).