|The 6200 is a very low end card. It doesn't require an aux 4-pin power plug connection so the PSU upgrade probably wasn't even necessary.|
The white wire you mentioned is for the -5V....it's optional, some PSUs have it, others don't. Does your motherboard have a 20-pin main ATX connector or 24-pin? If it's 20-pin, make sure to unclip the +4-pin plug from the 24-pin plug on your new PSU & tuck it out of the way. And make sure the ATX12V 4-pin plug is connected to the board. Other than that, the HDD, optical drive, floppy drives, etc connections should be self explanitory.