Hello all,
 
I plan on building a new system soon and was wondering if the 650gq and 750gq use the same cables. I know they are not compatible with other PSUs outside of their product line, but I don't know if they're ok to use within the same product line. 
I did buy a 750gq years ago and changed out my old broken 650gq but didn't change the cables, and it has been working fine, but I recently discovered that cable capability is not always a thing and can break components. As I said, there have been no problems so far, but the last thing I want to do is use my 750 PSU with 650 cables in my new system and break something. Unfortunately, I kept my 650gq cables in the same place as my 750gq cables, and they've been mixed together, so I don't know which ones came from which. 
 
I've tried reading around, and someone reported swapping from a 750gq to an 850gq didn't work, but I couldn't find out if this was because of a change unique to the 850, not the 650/750. Also, it could have been due to faulty cables, not the PSU change, as changing the cables did fix the issue.  
 
If anyone has experience or some concrete information on the similarities/differences between the different GQ cables, I'd really appreciate it, as I'd rather not have to buy a new PSU when I have a perfectly functional one available. 
 
Thanks for any help you can offer.

Just use the cables that came with the new PSU. EVGA changed pin outs on their cables for the same exact lineup, which is a weird thing to do on their part.