rb150 - upgrade firmware

Hello. I have one old rb150.
I tried upgrade routerboot to 2.18

/system routerboard upgrade
/system reboot

and routerboot is still 2.6

Then i tried upgrade firmware via serial console. Everythinks works ok - file transfered, but after upgrade is still old firmware 2.6

Is there any solution how upgrade routerboot?
resources.jpg
serial.jpg

nobody?