DSC Problem - Help Requested

My recently acquired 2000 323i has a problem with ABS/DSC system. Initial problem occurred when stopping and all 4 wheels locked up. I heard precharge pump and was able to remove fuse 61 which released brakes. Now the ABS & DSC lights were on. Two days later the instrument cluster no longer operated. Check codes but no communication. Spoke with BMW parts vender and they suggested DSC electronic model. Ordered and installed per instructions but problem still occurs when fuse 61 us in place. Also, after failure the speedometer doesn't work until complete system reset and then only for a few minutes. Does anyone know of a logic diagram for the system so I can trouble shoot myself or do I need to visit the $$$dealer$$$$.