LG L9 P760 Security Error - Phone Won't Turn On, Hard Reset Fails, Software Reload Issues

Hello.
The problem appeared when trying to switch on the phone, the LG logo appears, and under it Security Error information after a few seconds the phone turns off.
My knowledge resulted in a hard reset, but unfortunately the phone does not respond to this option.
I decided to give the phone to the local repair point, where I was informed that the problem is known will require re-loading of the software which has been "sprinkled".
It was supposed to be easy, fast and cheap.
Today, from the repair point, I receive information that there is a problem connecting to the phone despite having specialist equipment, boxes and other necessary things.
As I was explained when trying to connect to the phone, you need a code, key or something similar.
The service point declared that this security will try to get around.

A separate way in conversation with an authorized LG service, you have also informed me that this is a known and simple problem to be removed, although interference into the memory sector responsible for the phone's imei is necessary, and this may have problems for local repair points.
The opinion of an authorized service technician confirmed this fact.
I forwarded the phone for repair in my town to reduce the time it would be needed to deliver to an authorized LG service.
The price for the service of restoring the phone to "life" in both cases is the same.
I will mention that the phone worked until the very end, although the day before the security error the system's web browser stopped working.
I appeal to experienced colleagues of service technicians to express an opinion on the problem.
Thank you in advance.
Greetings.

Yesterday I did a different LG model, but the error itself, the repair lasted one hour.
However, each case may be different. A service with these access codes is something that turns.

Maybe a colleague will drop in how effective the local service is to get a phone call ???

It depends on what equipment they have, I personally do lg box z3x.

I confirm exactly the same model with the same problem I did during the week and Z3x coped, i.e. the new soft box restored the phone back to full efficiency, I will add that I still made a hard reset on the sofa because I was mulching the phone.

Thanks for the answers.
It is comforting, as it results from your experience, that the phone definitely goes "resuscitate"
In case of problems that a local service technician may have, I will use your example.

I will ask you out of curiosity, because when I was looking on the Internet, such a repair can be done at home without boxs and other specialist tools.
For example:
http://forum.android.com.pl/topic/133722-wgry...w-lg-alternatywna-i-prostsza-metoda-by-bride/