Northbridge of Via KT133A faulty!
The Northbridge VT8363A of the chipset KT133A from Via Technologies is responsible for system crashes in connection with Athlon-C processors! The curious thing is that this Northbridge was developed especially for the new Athlon-C models with 133MHz FrontSideBus. After an error in the southbridge of the KT133A (VT82C686B) was recently discovered, it now affects the other part of the chipset as well.
The problems manifest themselves in the fact that the PC hangs when restarting or the screen simply hangs up remains black. However, not all KT133A mainboards are affected by this problem. The stepping 1EA0 and 1EA4 are affected, the stepping 2EA1 is obviously free of errors. You can read the stepping in the 3rd line of the Northbridge lettering. However, since this is located under a cooler, even if only a passive one, you should not try to remove it. The cooler is difficult to remove, but it is even more difficult to properly reattach it to the northbridge.
It is still unclear whether the problem can be solved with a BIOS patch. According to information from Stephan Schwolow, an employee of MSI Germany, the bug can be fixed in 30% - 40% of the cases by increasing the I/O voltage in the BIOS from 3.3 to 3.45 volts. If you first want to test whether you are affected by the problem, you should perform a warm start from DOS mode or from Windows. If the screen stays black during the reboot or the PC hangs up during the restart, you are affected by the problem.
As the first mainboard manufacturer, MSI has already started to exchange affected mainboards. MSI is happy to provide its customers with further information on this subject by calling 069/40 893 - 191. Owners of motherboards from other manufacturers are advised to contact their dealer to have them checkedWhether the northbridge installed on the mainboard is faulty.
After the sparse information release and the concealment actions with the problem with the Southbridge VT82C686B, many of Via expect clear and honest statements about the new problem this time. Otherwise, Via's reputation will probably continue to decline and an Athlon-compatible chipset from a competitor is just around the corner with the SIS 735.