[LG G4c Questions & Answers] dominik-p:
Ok thank you. That was your output:

lrwxrwxrwx root root u:object_r:block_device:s0 bootdevice -> /dev/block/platform/7824900.sdhci
brw------- root root u:object_r:dm_block_device:s0 dm-0
brw------- root root u:object_r:dm_block_device:s0 dm-1
brw------- root root u:object_r:block_device:s0 dm-10
brw------- root root u:object_r:block_device:s0 dm-11
brw------- root root u:object_r:block_device:s0 dm-12
brw------- root root u:object_r:dm_block_device:s0 dm-2
brw------- root root u:object_r:dm_block_device:s0 dm-3
brw------- root root u:object_r:dm_block_device:s0 dm-4
brw------- root root u:object_r:dm_block_device:s0 dm-5
brw------- root root u:object_r:dm_block_device:s0 dm-6
brw------- root root u:object_r:dm_block_device:s0 dm-7
brw------- root root u:object_r:dm_block_device:s0 dm-8
brw------- root root u:object_r:dm_block_device:s0 dm-9
brw------- root root u:object_r:loop_device:s0 loop0
brw------- root root u:object_r:loop_device:s0 loop1
brw------- root root u:object_r:block_device:s0 loop10
brw------- root root u:object_r:block_device:s0 loop11
brw------- root root u:object_r:block_device:s0 loop12
brw------- root root u:object_r:loop_device:s0 loop2
brw------- root root u:object_r:loop_device:s0 loop3
brw------- root root u:object_r:loop_device:s0 loop4
brw------- root root u:object_r:loop_device:s0 loop5
brw------- root root u:object_r:loop_device:s0 loop6
brw------- root root u:object_r:loop_device:s0 loop7
brw------- root root u:object_r:block_device:s0 loop8
brw------- root root u:object_r:block_device:s0 loop9
brwxrwx--- root system u:object_r:mmc_block_device:s0 mmcblk0
brw------- root root u:object_r:sbl1_block_device:s0 mmcblk0p1
brw------- root root u:object_r:block_device:s0 mmcblk0p10
brw------- root root u:object_r:block_device:s0 mmcblk0p11
brw-rw---- root system u:object_r:misc_partition:s0 mmcblk0p12
brw------- root root u:object_r:persist_block_device:s0 mmcblk0p13
brw------- root root u:object_r:block_device:s0 mmcblk0p14
brw------- root root u:object_r:modem_efs_partition_device:s0 mmcblk0p15
brw------- root root u:object_r:modem_efs_partition_device:s0 mmcblk0p16
brw------- root root u:object_r:block_device:s0 mmcblk0p17
brw-rw---- root system u:object_r:block_device:s0 mmcblk0p18
brw------- root root u:object_r:recovery_block_device:s0 mmcblk0p19
brw------- root root u:object_r:tz_block_device:s0 mmcblk0p2
brw------- root root u:object_r:modem_efs_partition_device:s0 mmcblk0p20
brw------- root root u:object_r:modem_efs_partition_device:s0 mmcblk0p21
brw------- root root u:object_r:ssd_device:s0 mmcblk0p22
brw------- root root u:object_r:block_device:s0 mmcblk0p23
brw------- root root u:object_r:sec_block_device:s0 mmcblk0p24
brw------- root root u:object_r:encrypt_block_device:s0 mmcblk0p25
brw------- root root u:object_r:eksst_block_device:s0 mmcblk0p26
brw------- root root u:object_r:block_device:s0 mmcblk0p27
brw------- root root u:object_r:persistent_block_device:s0 mmcblk0p28
brw------- root root u:object_r:rct_block_device:s0 mmcblk0p29
brw------- root root u:object_r:block_device:s0 mmcblk0p3
brw------- root root u:object_r:block_device:s0 mmcblk0p30
brw------- root root u:object_r:cust_block_device:s0 mmcblk0p31
brw------- root root u:object_r:block_device:s0 mmcblk0p32
brw------- root root u:object_r:block_device:s0 mmcblk0p33
brw------- root root u:object_r:drm_block_device:s0 mmcblk0p34
brw------- root root u:object_r:mpt_block_device:s0 mmcblk0p35
brw------- root root u:object_r:modem_block_device:s0 mmcblk0p36
brw------- root root u:object_r:system_block_device:s0 mmcblk0p37
brw------- root root u:object_r:cache_block_device:s0 mmcblk0p38
brw------- root root u:object_r:userdata_block_device:s0 mmcblk0p39
brw------- root root u:object_r:rpm_block_device:s0 mmcblk0p4
brw------- root root u:object_r:grow_block_device:s0 mmcblk0p40
brw-rw---- root system u:object_r:aboot_block_device:s0 mmcblk0p5
brw------- root root u:object_r:block_device:s0 mmcblk0p6
brw------- root root u:object_r:block_device:s0 mmcblk0p7
brw------- root root u:object_r:tzbak_block_device:s0 mmcblk0p8
brw------- root root u:object_r:block_device:s0 mmcblk0p9
brw------- root root u:object_r:rpmb_device:s0 mmcblk0rpmb
brw------- root root u:object_r:block_device:s0 mmcblk1
brw------- root root u:object_r:sdcard_partition_device:s0 mmcblk1p1
drwxr-xr-x root root u:object_r:block_device:s0 platform
brw------- root root u:object_r:ram_device:s0 ram0
brw------- root root u:object_r:ram_device:s0 ram1
brw------- root root u:object_r:ram_device:s0 ram10
brw------- root root u:object_r:ram_device:s0 ram11
brw------- root root u:object_r:ram_device:s0 ram12
brw------- root root u:object_r:ram_device:s0 ram13
brw------- root root u:object_r:ram_device:s0 ram14
brw------- root root u:object_r:ram_device:s0 ram15
brw------- root root u:object_r:ram_device:s0 ram2
brw------- root root u:object_r:ram_device:s0 ram3
brw------- root root u:object_r:ram_device:s0 ram4
brw------- root root u:object_r:ram_device:s0 ram5
brw------- root root u:object_r:ram_device:s0 ram6
brw------- root root u:object_r:ram_device:s0 ram7
brw------- root root u:object_r:ram_device:s0 ram8
brw------- root root u:object_r:ram_device:s0 ram9
drwx------ root root u:object_r:vold_block_device:s0 vold
brw------- root root u:object_r:zram_block_device:s0 zram0

According to your screenshot the "dd" command did work right.

Just correct the count parameter and you will get a file with size 17.0kb

Yes it is a really small file. Please upload it. I will the paste the gdisk outputs.