[XDA Assist] XDA Visitor:
Having tried for several hours to try and find a solution to my problem I have been unsuccessful despite trying many solutions found on your site. So here is what I’ve tried.

Some history:

-	Bought the phone from Carphone Warehouse in February as an unlocked phone running Android 5.1.1 BTU firmware on the EE network

-	Discovered that the WIFI calling feature is only included with the EVR firmware so flashed the phone to EVR (G920FEVR3QOJF) using a modified PIT file (ZEROFLTE_EUR_OPEN_HIDDEN250M).

-	Phone worked flawlessly from this point.

-	In April I received the OTA to Android 6.0.1 (G920FEVR3DPD1)

-	Phone updated successfully and continued to work flawlessly.

Fast forward to 7 July:

-	Installed HSBC phone banking app with no issues

-	Plugged phone in to charge that evening (presuming it downloaded updates at this point)

-	Go to use phone after dinner and multiple apps start crashing and the phone keeps restarting randomly.

-	The phone gets stuck at the Samsung logo and has to be reset using power + volume down + volume up

-	I then try wiping the cache partition – does not solve the problem

-	I then try a factory reset/cache partition wipe.

-	Phone boots to setup screen, a couple of steps in apps start crashing again

-	I then try using Samsung Smart Switch to reinitialise the phone (Up until this point I was able to at least boot to the setup screen)

*	When it prompts me to back up my current configuration I chose not to as I had already factory wiped the phone.

*	It detects that I am running G920FEVR3DPD1 and downloads the appropriate firmware

*	30 minutes later after finishing downloading it tries to flash the phone.

*	An error message comes up saying it failed and to run Smart Switch in Emergency Recovery mode using a specific code which it provided.

*	I then run the recovery mode as directed and that fails.

*	The phone now sits there saying (“An error occurred while updating the device software. Use the Emergency recovery function in the Smart Switch PC software.”)

*	I note that there is a red error message on the screen that says “SECURE CHECK FAIL : (CM)”

-	At this point I get worried and download the G920FEVR3DPD1 firmware from Sammobile.

-	I install Odin 3.11.1 as instructed on their website and attempt to flash the firmware once again:

*	I place the phone into Odin download mode using Power + volume down +home

-	At this point I notice something strange:

•	ODIN MODE

•	Product Name: SM-G920F

•	Current Binary: Custom

•	System Status: Custom

•	Reactivation Lock: OFF

•	Secure Download: Enabled

•	KNOX WARRANTY VOID: 1 (0x0500)

•	RP SWREV: B:3 K:2 S:2

-	Prior to running Smart Switch my device status had said official and the Knox count was 0.

*	I used the G920FXXU3DPDP_G920FEVR3DPD1_G920FXXU3DPDP_HOME.tar.md5 file in the AP box without selecting repartition; Odin fails with the following log and the phone has the same error “SECURE CHECK FAIL: (CM)”

-	<ID:0/006> Added!!

-	<OSM> Enter CS for MD5..

-	<OSM> Check MD5.. Do not unplug the cable..

-	<OSM> Please wait..

-	<OSM> Checking MD5 finished Sucessfully..

-	<OSM> Leave CS..

-	<ID:0/006> Odin engine v(ID:3.1101)..

-	<ID:0/006> File analysis..

-	<ID:0/006> SetupConnection..

-	<ID:0/006> Initialzation..

-	<ID:0/006> Get PIT for mapping..

-	<ID:0/006> Firmware update start..

-	<ID:0/006> SingleDownload.

-	<ID:0/006> boot.img

-	<ID:0/006> NAND Write Start!!

-	<ID:0/006> cache.img

-	<ID:0/006> cm.bin

-	<ID:0/006> FAIL!

-	<ID:0/006>

-	<ID:0/006> Complete(Write) operation failed.

-	<OSM> All threads completed. (succeed 0 / failed 1)

*	I try again using repartition selected; Odin log is as follows:

-	<ID:0/006> Added!!

-	<OSM> Enter CS for MD5..

-	<OSM> Check MD5.. Do not unplug the cable..

-	<OSM> Please wait..

-	<OSM> Checking MD5 finished Sucessfully..

-	<OSM> Leave CS..

-	<ID:0/006> Odin engine v(ID:3.1101)..

-	<ID:0/006> File analysis..

-	<ID:0/006> SetupConnection..

-	<ID:0/006> Initialzation..

-	<ID:0/006> Set PIT file..

-	<ID:0/006> DO NOT TURN OFF TARGET!!

-	<ID:0/006> Can't open the specified file. (Line: 2408)

-	<OSM> All threads completed. (succeed 0 / failed 1)

*	There is no “SECURE CHECK FAIL: (CM)” error, nor has anything changed

*	I try again adding the (ZEROFLTE_EUR_OPEN_HIDDEN250M) pit file, same error.

*	I try again using the G920FXXU3DPDP_G920FEVR3DPD1_G920FXXU3DPDP_HOME.tar.md5 file in the CSC box; Odin log appears as follows:

-	<ID:0/006> Added!!

-	<OSM> Enter CS for MD5..

-	<OSM> Check MD5.. Do not unplug the cable..

-	<OSM> Please wait..

-	<OSM> Checking MD5 finished Sucessfully..

-	<OSM> Leave CS..

-	<ID:0/006> Odin engine v(ID:3.1101)..

-	<ID:0/006> File analysis..

-	<ID:0/006> SetupConnection..

-	<ID:0/006> Initialzation..

-	<ID:0/006> Get PIT for mapping..

-	<ID:0/006> Firmware update start..

-	<ID:0/006> SingleDownload.

-	<ID:0/006> boot.img

-	<ID:0/006> NAND Write Start!!

-	<ID:0/006> cache.img

-	<ID:0/006> cm.bin

-	<ID:0/006> FAIL!

-	<ID:0/006>

-	<ID:0/006> Complete(Write) operation failed.

-	<OSM> All threads completed. (succeed 0 / failed 1)

*	Phone has same error: “SECURE CHECK FAIL : (CM)”

*	I try again using the G920FXXU3DPDP_G920FEVR3DPD1_G920FXXU3DPDP_HOME.tar.md5 file in the CSC box, with the optional settings – repartition, Nand Erase All, Phone EFS Clear and Phone Bootloader Update; Odin log then appears as follows:

-	<ID:0/006> Added!!

-	<ID:0/006> Removed!!

-	<ID:0/006> Added!!

-	<OSM> Enter CS for MD5..

-	<OSM> Check MD5.. Do not unplug the cable..

-	<OSM> Please wait..

-	<OSM> Checking MD5 finished Sucessfully..

-	<OSM> Leave CS..

-	<ID:0/006> Odin engine v(ID:3.1101)..

-	<ID:0/006> File analysis..

-	<ID:0/006> SetupConnection..

-	<ID:0/006> Initialzation..

-	<ID:0/006> Erase...

-	<ID:0/006> Set PIT file..

-	<ID:0/006> DO NOT TURN OFF TARGET!!

-	<ID:0/006> Can't open the specified file. (Line: 2408)

-	<OSM> All threads completed. (succeed 0 / failed 1)

*	This time the phone does not display the “SECURE CHECK FAIL : (CM)”

*	I try again using all the same settings but adding the (ZEROFLTE_EUR_OPEN_HIDDEN250M) pit file; Odin Log then appears as follows:

-	<OSM> Please wait..

-	<OSM> Checking MD5 finished Sucessfully..

-	<OSM> Leave CS..

-	<ID:0/006> Odin engine v(ID:3.1101)..

-	<ID:0/006> File analysis..

-	<ID:0/006> SetupConnection..

-	<ID:0/006> Initialzation..

-	<ID:0/006> Erase...

-	<ID:0/006> Set PIT file..

-	<ID:0/006> DO NOT TURN OFF TARGET!!

-	<ID:0/006> Get PIT for mapping..

-	<ID:0/006> Firmware update start..

-	<ID:0/006> SingleDownload.

-	<ID:0/006> boot.img

-	<ID:0/006> NAND Write Start!!

-	<ID:0/006> cache.img

-	<ID:0/006> cm.bin

-	<ID:0/006> FAIL!

-	<ID:0/006>

-	<ID:0/006> Complete(Write) operation failed.

-	<OSM> All threads completed. (succeed 0 / failed 1)

*	Phone once again displays the “SECURE CHECK FAIL: (CM)”

-	At this point I go to a Samsung Smart Service centre to see if there is anything they can do; They take my phone away for half an hour and then come back and tell me that I have voided the warranty because I have flashed a custom ROM. Apparently just using ODIN voided my warranty according to their service technician.

-	This now leaves me at the point of having no further options left but to try and solve it myself. Any assistance would be greatly appreciated. Help please.