Specna Arms SA-E03 MK18 - Defect

I am selling my Specna Arms SA-E03 Bronze edition. This is a MK18 with the bronze Daniel Defense rail (copy).
This replica was once purchased as an upgrade project, but that was not successful. 1 skirm has been played with.
Currently the replica is not firing and I dare not say why. In addition, the trigger and fire selector are very stiff.
The upgrades that have currently been made are: A Guarder Infinity high torque motor, Big Dragon high speed gears (13:1) and a Gate X-asr mosfet. In addition, a longer inner barrel has been used, which comes from another Specna Arms.
Due to the replica being taken apart a lot, the zinc screws at the bottom of the pistol grip are no longer in the best condition.
If you like bringing replicas back to life or perhaps you are looking for a body and/or donor parts, then this might be something for you.
The replica comes with the original box and springs from Specna Arms (M90 and M110?).