My sim card is detected but it has no service.

[Android Central Question]

I have Samsung Galaxy Note 3 N9005. I just had it repaired from a cellshop because my LCD showed only black screen, so they had my white samsung note 3 lcd replaced with by a black samsung note 3 lcd of the exact same model. Everything worked just fine except that after repairing, my phone can't get any service from Globe. However, when I replaced it with a Sun simcard, it gets a high signal. To see if it was my Globe sim's problem, I tried placing my Globe sim card on another phone but it gets a high signal, as well. I was switching it for some time and the results were consistent. Sometimes I get a short spike of signal from Globe but it immediately fades away. After some time, I tried placing another Sun sim card into my phone. This time it showed no service, and now when I placed back the Sun sim card that used to work, it shows no service anymore. I'm really confused whether the problem is a hardware or software problem. Do you guys have any idea on how to fix this?

 

[belodion]

Perhaps damage or disturbance was done during the screen replacement?