huawei trt-lx2 dead after flash

phone was bring for flash because it was custom rom so customer bring it to me to flash stock. but now only green light and detect as Android Adapter PCUI
phone was TRT-LX2C636B150 i flash downgrade file TRT-LX2C636B140
now i need support team help to give back life to this phone, otherwise i have pay for new phone.
pls help me.

Quote:

SigmaKey v.2.30.00 Sigma dongle 2.30, Initializing...OK Pack 1: Not activated Pack 2: Activated Pack 3: Activated --------- 2019-03-12 00:02:49 --------- SigmaKey 2.30.00 Qcom: Write firmware ^ Android Sooner Single ADB Interface, Version 0.5, Name: QC_REFERENCE_PHONE, Serial number: S5X7N18116007722 (ADB) Writing flash...UPDATE.APP Firmware: TRT-LX2C636B140 This operation may brick the phone! Are you sure you want to proceed? [YES] Phone model: TRT-LX2 Version: TRT-LX2C636B150 Writing flash rpm...OK Writing flash tz...OK Writing flash sbl1...OK Writing flash apdp...OK Writing flash msadp...OK Writing flash modem...OK Writing flash dsp...OK Writing flash cmnlib...OK Writing flash keymaster...OK Writing flash cmnlib64...OK Writing flash mdtp...OK Writing flash devcfg...OK Writing flash lksecapp...OK Writing flash aboot...OK Writing flash recovery...OK Writing flash erecovery...OK Writing flash system.0...OK Writing flash system.1...OK Writing flash system.2...OK Writing flash system.3...OK Writing flash system.4...OK Writing flash cache.0...OK Writing flash boot...OK Writing flash vendor.0...OK Writing flash product.0...OK Writing flash userdata.0...OK Writing flash...Done --------- 2019-03-12 00:17:26 --------- SigmaKey 2.30.00 Qcom: Enable downgrade Android Adapter PCUI (COM191), Provider: Huawei Incorporated, Driver ver.: 2.0.6.725, Date: 12/28/2015, USB\Vid_12D1&Subclass_11&Prot_22 Error writing to serial port