Based on the information you provided it is a good idea to test the system with the minimum configuration possible (one memory stick, no add-on cards, motherboard graphics only) since the POST code 50-51 indicates a possible PCI bus related issue.
Port 80h POST codes
It is also recommended to reset the BIOS settings back to default or a BIOS incremental update if needed.
DG41WV BIOS release notes
BIOS update instructions
DG41WV available downloads
In case the issue persists you may want to provide further information about the system configuration or if there was any other change before the issue started happening.