Seiko S651 Instructions Manual page 17

By turning on the auto illumination function, the display is illuminated every minute to signal the lapse
of time for the last 19 minutes of the countdown. If the countdown is repeated more than 10 times,
however, the display will not be illuminated.
Even if the TIMER mode is changed to another while the measurement is in progress, it continues
counting properly and the flashing TIMER mode mark indicates that the timer is in use. After the timer
is used, however, be sure to reset it to prevent the overconsumption of battery energy that would
shorten the battery life.
ALARM
In the alarm time setting, the flashing digits move quickly if button D is kept pressed.
When the time function is displayed in the 24-hour indication, the alarm is also displayed in the 24-hour
indication.
When setting the hour digits in the 12-hour indication, check that AM/PM is properly set.
If the watch is left untouched in the ALARM SETTING display with the digits flashing, it will
automatically return to the ALARM mode in 2 to 3 minutes.
The alarm can be tested by keeping buttons C and D pressed at the same time in the TIME/CALENDAR
mode.
ILLUMINATING LIGHT (Electroluminescent panel)
The electroluminescent panel loses its luminance as the battery voltage decreases. Also, its
luminance level decreases gradually with use. After 240 hours of use, the level decreases by about
half.
When the illuminating light becomes dim, replace the battery with a new one. If the illuminating light
remains dim after the battery is replaced, have the electroluminescent panel replaced with a new one
by the retailer from whom the watch was purchased, or an AUTHORIZED SEIKO DEALER. It will be
replaced at cost.
While the illuminating light is used, the watch gives out a slight noise. However, this is not a
malfunction.
17