Vostro 3450 fan not working even after cleaning

Hello everyone, I am new here  

So, basically I have an old vostro 3450 manufactured around 2011. It is  still has windows 7. The real problem goes after 20 - 25 mins of operating. At starting it's CPU Temperature : Core 1: 50 ;Core 2: 51
                                                                        HDD Temperature: 54                  [ Monitored through Open Hardware monitor ] 

But after 20 mins the result are very bad :- 

                                                              CPU Temperature: Core 1: 84 ; Core 2: 85
                                                             HDD Temperature: 66 

And after 10 mins the laptop freezes.

After the ePSA Test it said that the CPU Fan not responding. 

These were the attempt: 

Attempt 1 : 
Clean the laptop fan and tried to give stress to the fan through 3D MARK etc. 
Result  : The fan worked well and the temperature couldn't go beyond 64 Celsius. 
Problem : Back at normal stage within 15 days. 

Attempt 2: 
Blow air through fan but no cleaning ( as the fan was still clean )
Result: While blowing the fan can move freely but can't move on its own. 

Attempt 3:
Trying to ask in the community. 

These are all my attempts I did. This is not that I can't now operate my laptop as I have another dell vostro 15 3500 

But is needed for some application such as Photoshop etc.