Also know as Pacific Networks RT-150M (9V power adaptor version), this is a TL-WR741ND v1 rebrand for Pacific Networks, and will only accept firmware with Pacific Networks vendor bytes (in the file header). Others 3rd party(OpenWrt/DD-Wrt/TP-Link) firmwares does not have those bytes. This is identical to Multilaser RE027 router. Pacific Networks did not have any firmware available to copy vendor bytes but they were found out and are shown below.
Steps:
For next firmware update, you DON'T need to change the vendor bytes again, just download the latest firmware from TP-Link website and proceed to update.
All new mod/change now can be done according the original wiki page of TL-WR741ND.
Not tested yet, but should work same as TP-Link WR741 compatibility page.
All the internal images are the same as RNX-N150RT and TL-WR741ND v1/v2.