Freezing after bios installation

[lolof]

Do you see the soldered chip on the original one ?
Maybe the man who made the mod on your dreamcast didnt put a switch....
Maybe it is only wired. 2 wires must be put together to give access to the soldered chip and one wire must be remain alone. One of the 2 that are actually together should be connected to the remain one. You should better learn how this is build from here and find the good wires that have to be put together to give access to the original bios chip.

Read this thread, you will find Useful info :
http://www.assemblergames.com/forums/sho...hp?t=24880

Here the shematic :
http://www.dc-swat.ru/blog/hardware/16.html

Now, you can see that the wire who is coming from the leg 12 of the Soldered bios chip is put together with the wire soldered on the D501, you have to separate those 2 wires.
Then you should link the wire that come from the leg 12 from the original bios chip with the wire that is soldered on the D501 component.

If it works, you should put a on/on switch, it makes life easier.

If you cannot do it after reading those links, maybe we cann help you if you post some photos...

Good luck