Please see the following picture, you will find Clear CMOS jumper JP5 near the lithium Battery.

Step 1 :
Please set JP5 jumper to Clear CMOS side for 2 or 3 seconds, then set it back as Default again which will clear Bios CMOS setting.

Step 2 :
Connector CRT monitor and boot up again Flex600 motherboard→Press "DE" key to enter Bios CMOS Setup Screen→Select "Load Optimized defaults"→Press "Y"

Step 3 :
Select "Frequency/Voltage Control"→"CPU Host/SDRAM/PCI Clock: Default→
Press Enter to change→For example : if your CPU and SDRAM external frequency is 133Mhz→Then set it as 133/133/33(Our PCI Clock is 33 Mhz)

Step 4 :
After set CPU & SDRAM & PCI Clock→Save & Exit→Reboot and check boot up screen, then you will see correct CPU type and frequency.