Aaeon SBC-656 User Manual page 32

You can connect an external jumper cap or switch to clear CMOS.
Clear CMOS procedure:
1. Disconnect all power source.
2. Move J3 from 1-2 to 2-3 for few seconds.
3. Move J3 back to 1-2.
1 2 3
Protect* Clear CMOS
1 2 3
1 2 3
J3
*default
22 SBC-656 User Manual