I have a Blackgold quad TV card (2 sat, 2 freeview). It has worked well for years until it lost everything - all channels black. Fixed that with latest drivers and an update to DVBViewer.
Then I lost Freeview - every channel. With no new software and re-installing clean making no difference I waited until I could try out a different Blackgold card (same hardware but an updated pcb).
The newer Blackgold card, as installed on a Core i5 worked on all channels and across Freeview and Freesat.
Update drivers from Blackgold and version 6.0.3 of DVBViewer and the newer pcb in the Core i7 Pc