Corsair K90 - 'z' to '.' dead and pause/play

An issue just developed for my K90:

Keys: z,x,c,v,b,m,comma,period,pause/play media key have developed issues - other keys on this row (l/r shift, \, /, n are all fine):

Initially none of the stated keys will work, however if you repeatedly push the non-working 'z' key, say 100-200 times, it will suddenly start to work again, and with it all of the other keys.

After an irregular amount of time all of the stated keys will then stop working - this can be a few seconds to a few minutes, and occurs regardless of use; ie. continuous use of z-period does not stop the issue from recurring. SHIFT+key for any of these keys also does not work.

All LEDs work, issue persists between computers, I've updated the firmware and generally done everything I could think of.

I bought the keyboard at release so I'm guessing it's now out of warranty too - I'd be very interested if wiring information regarding these keys could be provided as it sounds to me as if this is a soldering issue where the z row and pause media key share a weak point.

Any help would be appreciated!