Error code PM5 help

[Sully]

Hi,
I was halfway through a 10km piece this afternoon and the display started scrolling though the different displays (watts, cals etc) without warning. It eventually stopped and I carried on working out. At the end the menu button wouldn't respond as if the screen had froze. I took the batteries out and when I put them in I got an error message saying "code 4 -5" and the screen wouldn't move. Anyone got any ideas?
This is a 2nd gen ski erg less than 3 months old.

[c2jonw]

Sully- Code 4 indicates a stuck key- confirmed by the scrolling UNITS. This may mean that the rubber key is actually stuck in the in position or there is some contamination inside that is making the PM5 think the key is down. Or it may be an internal error that might clear by leaving the batteries out longer or resetting the monitor. Please call C2 tech support......C2JonW

[Sully]

Thanks for taking the time to reply. I posted a photo on Twitter of the error code and someone said to hold down a button when putting the batteries back in so I'm gonna try that before I go to bed tonight.
Excuse my ignorance but what key?

[c2jonw]

Sorry- key= button, and in this case it would be the UNITS button that is either physically stuck in the depressed position or being actuated by some moisture or contamination inside the PM5