Look for the words "ON", "OFF", or "AUTO" on the bottom or top right of the LCD.
A: Usually means a programming conflict (e.g., OFF time set before ON time without crossing midnight, or overlapping programs). Press R and reprogram. sinotimer tm-630s manual
A: The TM-630S uses a crystal oscillator. ±0.5 seconds/day is normal. If losing minutes, the internal crystal may be damaged. Press R and reset. Look for the words "ON", "OFF", or "AUTO"