Compass HMC5883L issue

I'm trying to put a HMC5883L to run but the output is always incomplete, like 80...190°. I need a 0...360°. The problem wasn't om my module, once I tested with 3 diferent modules. The module I'm usin is the GY-87. The magnetometer is incorporated to the MPU6050. The code to bypass and access the HMC5883L is working fine. Please only bid if you know how to put it to work. We can use skype and TeamViewer to the project. I need it for today.