Typical freeze screen (SP-S2
) on startup.
A freeze at startup on the shown screen (with no cyclic reset) is caused by the RTC not outputing a time pulse at all.
The system ROM doesn't give a CALENDAR ERROR in this particular case because of a programming oversight.
- Check battery voltage
- Check 32768Hz crystal
- Check uPD4990 traces, especially power and pin 11 (TP)
- Check NEO-F0 interface pins
- Check 74HC32 and traces to uPD4990
- Try to reset Backup RAM content:
- Either remove battery
- Or flip all dip switches to on and then power on the board. Then turn off the board and return all dips to normal settings
- You can use unibios to skip this error