iPhone Network IC problem repair | No Service / Signal Weak

There is so few Qualified technician to repair Network IC problem of iPhone

Yes, especially in Malaysia. They just know how to blindly changing the IC, but don't know which one is the real problem.
A lot of iPhones with the cellular signal problem I fixed. Most of these have been already attempted repair from other technicians.
They didn't know how to diagnosis and fix the real problem, they just keep changing the IC one by one until the problem is gone.

So this is why they need your iPhone for weeks or a month. 

This is one of the kind Network IC problem.
It only can detect Maxis, but no others.

This iPhone, the owner sent it to another shop before and collected back after a month but with the same problem. They failed to repair it.
Once in our hand, we opened up to check the motherboard condition. As usual cases we encountered, most of the Network IC and parts already been replaced and messed up.

For a problem like above, it would just take me 1 to 2 hours to repair. But let say if someone repaired it before,  I might need to replace everything related to the network that they touched.
And the time I need to repair it becomes much longer.

What have they done on it (Technical explain)

They removed the WTR transceiver IC and measured the resistance but found nothing unusual. Then they usually started to blindly replace network IC one by one.
Some even will go to reball the Baseband CPU and changed BBPMU.

They touched almost everything related to the network. Yet, they can't fix the problem.

If you are a technician who reading this and expecting to get the solution from here, then sorry. I can't provide what you wanted.

Because Cellular Network is complicated in a smartphone nowadays. When I was teaching my students about the Cellular Network, it took me many hours to complete the cellular theories. So I'm not gonna explain things in a blog like this.

If you learned from another school before and still unable to repair this, I believe:
1. You have an outdated knowledge
2. You don't know iPhone board components very well  

4. You lack the procedures of diagnosis

iPhone Network IC problem fixed 

Done! All carriers detected. 

Why I'm different from them?
Because I didn't just learn from one academy. The knowledge, skills, and tools are combined together from multiple academies.
Have you heard of GLON, FAE, FoneKong, FixST, and REWA?

Is there such a guy who keeps paying money to repeat learning similar things from different schools?
I think no. Not even me.

Then how I do that?
Well, it's easy. I just sent my workers and friends to go to a different famous school and then we shared the things we learned.