In SharePoint 2010, Normal search is working and People search result is not working fine. Why? Finally, you may have configured the user profiles synchronization & Search services. Also, you may be able to see the number of profiles under "User profile service" and contents under "Search Service".

Finally, you may have configured the user profiles synchronization & Search services. Also, you may be able to see the number of profiles under "User profile service" and contents under "Search Service". 

Reason:

You may have forgot to add the URL to crawl the people in Search service "ContentSource". So, just add the exact url which will start "SPS3://".

Example:

SPS3://km.sensoft2000.com (just an example)

 

sps3://sreenu:1111

 Thats it....