Dell E6330 Laptop Fan Malfunction Error on Start Up

Hi,

I have a Dell E6330 with Fan Malfunction Error on Start Up. I've run the onboard diagnostics (using f5 option when error displayed) and all tests including the fan tests have passed with no errors.

I receive this error message probably 1 in 3 start ups.

I've updated the BIOS and cleaned fan as suggested by online forums but issue persists. 

Also, fan when it kicks in can be a little loud (after 30-60 mins of use) but not too distracting before it quietens down again and then follows with a loud and lengthy repetitive/revving cycle  30-60 mins later lasting probably around a minute or 2 before it quietens down again but relatively quite other than that and not sure if this is normal.

I've noticed upon opening the laptop, there was some black tape. I bought this second hand on ebay so not sure if it's supposed to be there and if linked at all to problem. Reached out to ebay seller for clarification and awaiting a response

Please see images below for clarification.

Any help would be much appreciated and thanks in advance :)

Yusuf