The Venera landers stopped functioning because the solder in their circuits melted. Higher temperature solder could have been used preventing this problem, but

The Venera landers stopped functioning because the solder in their circuits melted. Higher temperature solder could have been used preventing this problem, but the key issue is that silicon no longer functions as a semiconductor at these temperatures. Silicon carbide still works as one though and we're now starting to see silicon carbide electronic circuits and foundry processes to make them.