Ok, we need to set a few things straight here, as you obviously (sorry ... ) havn't researched nearly enough on modding the Xbox.
Here goes ..
Firstly, so far as I'm aware, the ONLY BIOS you should be using with an X3 (or X3ce) chip is the X3 BIOS - current version, 1959 or the PLUS which is for 1.6 and 1.6B boxes. There IS an Evox BIOS but I believe this is normally associated with Xecuter 2.6 chips.
After you said you flashed the chip - you said 'Everything works fine' - please define ?
YES you can have a few different BIOS stored on the X3 to use - however - there is a total of 2mb for storing these BIOS and these can be split up into different 'banks' like so (bearing in mind the correct bios is EXACTLY 1024kb in size) .....
multiple 256kb banks, 2 x 1mb banks or 1 x 2mb bank.
So you could store 2 BIOS for example of 1024kb in banks 1,2,3,4 and one in 5,6,7,8 (see switch info on team xecuter site)
Last thing - dashboards are software that will run once the chip is functioning properly with it's BIOS. All the chip does is disable the protection on the Xbox - basically speaking. It does not store any games, no software(as such), and only has basic settings, utilities and functions that are features of the BIOS. SO - any dashboards, games, copying utils and such need to be installed after this is in place and copied to the hard drive.
so, now , you need to read some more inormation about it all - it's all here, as that's how I learned then do the following, just to be sure ....
Get the 1959 BIOS.
Put your switches in the on,on,off,off,off position
Re-Flash your X3 with the 1959 BIOS (boot from the backup if you need to but LEAVE the switches)
Lastly, once the BIOS is in place, press and HOLD the white button with the controller in port 1 and boot the Xbox. Contnue holding the button until the BIOS screen appears - not the blue Cromwell one, the 1959 BIOS screen.
In theory, after flashing, it should appear normally and automatically, but don't take any chances !!!
There ... rant over !! ..sorry, but SO many people are asking the SAME questions over and over and seem too lazy or unable to READ !!!
J