Samsung Galaxy S3 T999 poor vibration after front assembly replacement

Hello I am a repair shop up in rhode island and ive encountered something ive never encountered before, although the s3 front panel is pretty routine im not sure what happened. the vibration is very poor compared to what it used to be. i gave the phone back to the customer thinking it wouldnt be that big of a deal but apparently it was so i ordered a new vibrate motor and put in a new one and it still was very poor, i told the customer i couldnt fix it but now im thinking.. i was looking at another s3 motherboard and was looking on the bottom side and there are 2 metal contacts for the vibrate, is it possible that those 2 metal contacts arent making a good connection and i need to pry them out a little bit for them to make a better connection on the vibrate motor connections? any input on this matter would be appreciated, i dont have the phone anymore but the customer is extremely upset, im not sure if ill ever get the chance to open the phone up and try but would like to know if i encounter this again in the future. thanks for your help. -pearlcellular