Yup.
You should try to reflash it with tftpd method.. but for that you need serial access to unbrick it.
The following howto is for the MR3020 but describes exactly what need to be done to reflash via Serial and TFTP. [ediy.com.my]
You can find the serial-informations for the MR3040 here (openwrt) (and on the same page details about tftp update)
That maybe helps to figure out to get it back working.
You should try to reflash it with tftpd method.. but for that you need serial access to unbrick it.
The following howto is for the MR3020 but describes exactly what need to be done to reflash via Serial and TFTP. [ediy.com.my]
You can find the serial-informations for the MR3040 here (openwrt) (and on the same page details about tftp update)
That maybe helps to figure out to get it back working.