moble phone connecting problem

[Dharmik_1999]

i am  unable to connect my  phone to my pc for file transfer . when i connect my phone to laptop by using datacable my phone automatically disconnects. i also try to connect my phone by using another datacable but it shows same problem. furthermore, i think that i have issue in my mobail phone so i went to the service center an i talk them problem they check my phone and also show me that  my phone  connect in their pc. 

[#2]

Try this if it is an Android Phone... https://www.wideanglesoftware.com/blog/transfer-files-android-to-pc-using-usb.php#droid-transfer
For iPhone simply download iTunes and install it then register your phone. https://support.apple.com/en-us/HT210612