I'm assuming you are using NBHUtil by Olipro. NBHUtil asks you for an output file before writing.
Run NBHUtil, on the "Build NBH" tab select Raphael as the target device and it will fill up some of the fields. You can see the NBH Item section shows SPL, Radio, OS, Diag, and Splash text boxes
. Click the button beside Splash
text box, it will open a window. Select the Splash.nb
file you've created before. After selecting, it will pop-up again another window asking you what file to save it. You can directly put KAISIMG.nbh so you can flash it directly