PSU issues - Is pin 15 (ground) neccesary?

Hello All, First time poster -

Been troubleshooting a new PC build - I am building using some existing parts (including an existing PSU).

Was experiencing random freezes and BSODs - did all the typical troubleshooting etc....eventually narrowed the issue down to what i think was the new video card.

RMA'd the card - and am expecting UPS to deliver the replacement card tonight.

HOWEVER - was prepping the system for the new card, and noticed that the wire for Pin 15 on the PSU was detached....Plugged it into a PSU tester, and everything looks good except for -5v which shows a fail.

Pin 15 is a ground wire (one of many) - what does this mean to me?

Should I replace the whole connecter? Can I run without an attached Pin 15?

Is it safe to plug my new video card in, and power up without pin 15 attached?

Thoughts?
 
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