Checking Marita's walkthrough, there are phone numbers up the wazoo, and nearly all of them are listed in your phone so you never type in the number.
There is one place where you have to enter a PIN into someone else's phone, and you have to talk to someone to get clues for the PIN number. This is probably one of those cases where you have to go through the motions of solving before the game will take the number, even when you already have the correct number.
http://www.gameboomers.com/wtcheats/pcAa/artofmurder.htm Fix James' mobile phone: Look close at Nicole's desk.
Place the cables at bottom left of the desk (left of the keyboard).
Add battery to cable. Then use James' mobile on the cable-battery setup.
Pin number: It asks for a pin number. Talk to Ruth. James' birthday is May 24, 1956.
Go back and look close at the damaged mobile on Nicole's desk.
Enter the numbers by pressing the keys. Use the blue top right button to backspace-clear errors.
Press the blue Okay button at the center when done.
The permutation of James' birthdate is not the pin number.
Use clean swab on James' ID and read it to get XFAD 8673.
Enter 8673 on the damaged mobile and then press the center blue button (Okay).
Clear a wrong entry by clicking 4 times on the button right of the blue button.