tbred 2100+ AIUCB0240 and confused?

I have general question about tbred2100+.

Have a couple of systems running these chips, one is my MSI KT333 ultra which is running nicely 13x166 without any problems but when I select a higher or lower multiplier in the Bios system wont boot at all. So, last night I went and bought me the FIC AU11 which has a lot of good reviews and it seems like FIC worked together with Epox before making this board. Now, after putting together my Fic AU11 im able to run at 166 but its not been very stable and I want to select a lower multiplier.

Here is my main question with this nforce board(au11) I have all of the multipliers available (3-24) BUT anytime I pick anything over or under its default multiplier the system will boot but at 1500+, so it seems to be resetting itselft to a safe mode speed.

Here is the tricky part with my 1800+ cpu it seems to take the changes when I change the multipliers.

Is there any mod I need to do to 2100+ chip so when I changed the multipliers eighther over or under it will boot with the correct settings?

Thanks in advance

Yes, you have to connect the last L3 bridge to make it go from L3 .||:|: to L3. ||:|| this will set the x8bit to LO and will give you access to either all the multies or x5-x12.5, which is what you want I assume, there is no mod to make it work stable at higher multies except blowing/connecting bridges to hardcode a different default multiplier. for multiplier codes/setting go here

Both of the mobo's you have do not allow you to change the CPU multiplier when the 5th L3 bridge is open. The Coolest is correct that you need to connect (close) the 5th L3 bridge, and you should have access to the lower multipliers (5-12.5). This will allow you to raise the FSB speed and get more memory bandwidth as well, assuming that your memory will run at higher FSB speeds.