For me, about 2-3 months ago, I managed to enter the fastboot mode and gave him 2 files, now he has such a loop over and over again and unfortunately SB3.0 does not work. That's why I asked for your files and contenet and the mayby will work 
Format: Log Type - Time(microsec) - Message - Optional Info
Log Type: B - Since Boot(Power On Reset), D - Delta, S - Statistic
S - QC_IMAGE_VERSION_STRING=BOOT.BF.3.1-00311
S - IMAGE_VARIANT_STRING=MAATANAZA
S - OEM_IMAGE_VERSION_STRING=scl_xa242_060
S - Boot Interface: NAND
S - Secure Boot: Off
S - Boot Config @ 0x000a602c = 0x000000a1
S - JTAG ID @ 0x000a607c = 0x100320e1
S - OEM ID @ 0x000a6080 = 0x00000000
S - Serial Number @ 0x000a4128 = 0x100caf6f
S - OEM Config Row 0 @ 0x000a4150 = 0x0900000000000000
S - OEM Config Row 1 @ 0x000a4158 = 0x0000000000000000
S - Feature Config Row 0 @ 0x000a4160 = 0x14000000000009a0
S - Feature Config Row 1 @ 0x000a4168 = 0x0342f80200000005
B - 3324 - PBL, Start
B - 6728 - bootable_media_detect_entry, Start
B - 8032 - bootable_media_detect_success, Start
B - 8037 - elf_loader_entry, Start
B - 11446 - auth_hash_seg_entry, Start
B - 11698 - auth_hash_seg_exit, Start
B - 60208 - elf_segs_hash_verify_entry, Start
B - 112801 - PBL, End
B - 124653 - SBL1, Start
B - 216763 - pm_device_init, Start
B - 277001 - PM_SET_VAL:Skip
D - 59170 - pm_device_init, Delta
B - 278160 - usb: usb: hs_phy_nondrive_start
B - 282155 - usb: usb: hs_phy_nondrive_finish
B - 285541 - boot_config_data_table_init, Start
D - 0 - boot_config_data_table_init, Delta - (0 Bytes)
B - 295667 - CDT Version:3,Platform ID:8,Major ID:1,Minor ID:0,Subtype:0
B - 302377 - sbl1_ddr_set_params, Start
D - 30 - sbl1_ddr_set_params, Delta
B - 309880 - Pre_DDR_clock_init, Start
D - 396 - Pre_DDR_clock_init, Delta
B - 324916 - pm_driver_init, Start
D - 1830 - pm_driver_init, Delta
B - 326777 - clock_init, Start
D - 183 - clock_init, Delta
B - 331443 - boot_flash_init, Start
D - 33367 - boot_flash_init, Delta
B - 372313 - Image Load, Start
D - 39437 - QSEE Image Loaded, Delta - (394044 Bytes)
B - 411780 - QSEE Execution, Start
D - 65941 - QSEE Execution, Delta
D - 213 - boot_pm_post_tz_device_init, Delta
B - 481320 - Image Load, Start
D - 19642 - RPM Image Loaded, Delta - (161732 Bytes)
B - 653767 - ZTE_POWER_ON_NORMAL
B - 705709 - Image Load, Start
D - 38125 - APPSBL Image Loaded, Delta - (425972 Bytes)
B - 743864 - sbl1_efs_handle_cookies, Start
D - 0 - sbl1_efs_handle_cookies, Delta
B - 751215 - SBL1, End
D - 628819 - SBL1, Delta
S - Throughput, 10000 KB/s (981812 Bytes, 94180 us)
S - DDR Frequency, 518 MHz
S - Core 0 Frequency, 1190 MHz
Android Bootloader - UART_DM Initialized!!!
[0] welcome to lk
[0] SCM call: 0x2000601 failed with :fffffffc
[0] Failed to initialize SCM
[10] platform_init()
[10] target_init()
[10] Waiting for the RPM to populate smd channel table
[10] smem ptable found: ver: 4 len: 17
[20] ERROR: No devinfo partition found
[20] Neither 'config' nor 'frp' partition found
[20] zte_power_on_ctrl no operation
[30] ----fota cookie is [0xffffffff]----
[30] Loading (boot) image (8941568): start
[870] Loading (boot) image (8941568): done
[870] Authenticating boot image (8941568): start
[940] Authenticating boot image: done return value = 1
[980] DTB Total entry: 170, DTB version: 3
[990] Using DTB entry 0x0000011b/00010001/0x00000008/0 for device 0x0000011b/00010001/0x00010008/0
[990] cmdline: noinitrd rw console=ttyHSL0,115200,n8 androidboot.hardware=qcom ehci-hcd.park=3 msm_rtb.filter=0x37 lpm_levels.sleep_disabled=1 earlycon=msm_hsl_uart,0x78b1000 androidboot.serialno=100caf6f androidboot.authorized_kernel=true androidboot.baseba[1020] Updating device tree: start
[1080] Updating device tree: done
[1080] Channel alloc freed
[1100] booting linux @ 0x80008000, ramdisk @ 0x80008000 (0), tags/device tree @ 0x82000000