Solution:

Problem description: PCA-6167 has an Ultra Wide SCSI fail to work problem. Problem analysis: The failure problem only happen in below system configurations :PCA-6167 with Pentium Pro 200Mhz and 512KB cachePCA-6645A VGA PCI cardPCA-6113P3 Rev. C1 backplaneWhen PCA-6645A VGA card plug into PCA-6113P3 backplane PCI slot 3, the PCA-6167 CPU card's Ultra Wide SCSI will become malfunction. After our R&D and QE engineers further study, the problem is caused by two signals, SCSI CLK and PCI CLKD, shared together internally, and exist on CPU clock jumpers being set to 66Mhz only. In our further experiments, there is no Ultra Wide SCSI failure problem when CPU clock jumpers set to 60Mhz and 50Mhz, or uses PCA-6645A VGA card on PCA-6108P3 and PCA-6106P3 backplanes.There are totally 400 pieces plus engineer samples existing this problem. The detail solution is available from attached file.