After few weeks with poor réception on my nexus 4, and being sure that it was a problem with my phone du to multiples search on the internet and confirmation from koodo tech that I should have a full strenght signal at home, I decided to fix it myself. Here is how. First, the symptoms. Signal strenght is not constant with the phone not moving, signal strenght will vary depending of the temperature of the phone, getting worst as the device heat up. Getting no service and not getting service after even in a good reception zone. The problem. Problem caused by poor contact between the antenna module and the motherboard. To fix, you have to open the phone. There is instructions for that on the internet. Note that if you screw it badly, your warranty will be void. Being careful here is the key.. The most délicate part is to remove the antenna module. Once done, you will see to small flat spring that line up with the antenna connection. Lifting them will make them getting better contact with the antenna. Just dont abuse on the lifting.... Reassemble the phone and enjoy better signal. This is not for everybody. I have good experience doing this kind of work. But this can help someone to diagnose his/her device and have it fixes.