I just replaced this PSU a month ago and I lost one of the secrws that connected it with the hashboards and tried to find a titanium screw in local shops and find nothing, and I took one of the screws from a house machine and it works fine for around a month now. I upload a photo if you didn't get my point.
As long as the screw is tight enough and the connection isn't loose - there shouldn't be a problem, I highly doubt that reason alone is what killed the PSU, what is your input AC voltage?