I have a pair of XFX HD 5750 video cards that both have failed fans (I know one of the cards is good). I also have a XFX R7770 with bad VRAM, but a good fan--same size and same heatsink mounts. The problem is that the R7770 has a 4-pin fan and the HD5750s have 2-pin fans (and solder points for the other two pins). What are the odds I could solder a couple extra pins in an HD5750 and it actually work w/ PWM?
Use a multi-meter to check if there is power on the solder points compared to the card with the pins?
Thanks for the feedback everyone. @MrMagic - Using a multimeter is a good idea, I don't know why I didn't think of that. @pisthai - The PWM fan is the generic BRYB connector. @MichaelaJoy - I don't have a scope and I'm kind of wishing I did. I might just go ahead and plug it in as is. Doesn't it make sense that the 2-pin card would still control the speed of the PWM fan via voltage?
Turns out it isn't a 4-pin fan connector on those cards. It is a 2-pin and 3-pin fan connector mount that overlaps and shares the same ground pin (and two of the pins aren't there). I ended up just swapping the fans and it works perfectly fine.