[One (M9) Q&A, Help & Troubleshooting] Qube-au:
So, I have a feeling I have an M9 that has suffered the dreaded dead NAND, but I want to be sure.

Phone has been working fine for long time now, no random reboots. Last night all of a sudden it just self reboots, and just stuck in a vibrate/boot screen with white background loop. I tried to get into recovery directly with Vol Down/Power but it boot loops at the silver HTC logo/black screen. The only way I can get into recovery is via fastboot while it's boot looping on the silver logo splash screen, I hold vol Up/Down and I get into fastboot. I can either choose to go to download or TWRP recovery.

Download mode screen shows

*** UNLOCKED***
htc_himauhl PVT S-OFF
CID-11111111
LK-1.0.0.0000
RADIO-01.01_U11440801_96.01.51207G_F
OpenDSP-15.6.1.00522.8994_1026.
OS-3.50.710.1
May 27 2016, 15:22:38(761596)

If I go into "System" info I can see the eMMC type and everything else.

SN: FAxxxxxxx
IMEI: xxxxxx
MEID:
eMMC: Hynix 29824MB 61079552? sectors
eMMC cid: 90014a48.42473465.xxxxxxxx.xxxxxxxxx
eMMC firmware version: : 0x7?
eMMC life[267-269]: 03 01 0b?
sbl1-1.2.50.1.3
tz-3.01.193.02
TP: Maxim-1.31.55_p8_chipID-0x78_twID-0C?
CIR: Peel - version 20
SHUB: 001.065.028.037.001.001
LCD: HIMA FHD Tianma/Renesas video mode dsi panel?
CPU: Unknown
CPU rev: 2.1
DDR: 000000001, 3GB

HOWEVER fastboot getvar all doesn't show the eMMC type - that being said my OTHER HTC M9 that works doesn't show that info - it the same as the dead M9 - even though other posts I've read suggest that because there is no eMMC info it must be dead NAND - but I can see the eMMC info in "download mode" screen.

(bootloader) kernel: lk
(bootloader) product: htc_himauhl
(bootloader) version: 1.0
(bootloader) serialno: FAxxxxxxxxxx
(bootloader) current-slot:
(bootloader) imei: xxxxxxxxxxxxxxxxxxxxxxxx
(bootloader) version-main: 4.23.710.1
(bootloader) boot-mode: download
(bootloader) version-baseband: 01.01_U114401011_117.00.61117G_2_F
(bootloader) version-bootloader: 1.0.0.0000
(bootloader) mid: 0PJA10000
(bootloader) cid: 11111111
all:
finished. total time: 0.010s

So what I have done, went into recovery and tried to reflash custom ROM. Did not work. Had a copy of HTC RUU zip on external SD card, went into download mode and tried to flash, it begins does the pre-update flash but then when it tried to reboot into download mode to continue flashing the rest of the partitions - it gets stuck into the silver logo boot loop. So cannot flash HTC RUU. Have also tried to flash RUU using fastboot method but still same problems.

Have tried adb shell and manually mount the partitions but get "invalid argument" - which is odd, maybe because it's adb shell when in TWRP recovery.

"mount -t /dev/block/mmcblk0p067 /data"

Have reformatted the partition as ext4 with correct variables, but still cannot mount.

Have also tried a TWRP backup restore and no luck there.... it says it formats the various partitions but fails when TWRP tries to mount and fails to do the restore.

Any suggestions or ideas would be much appreciated.

Here is the output from the fastboot flash zip -it doesn't get past the preupdate stage - repeats over and over

htc_fastboot v3.0.9.2 (2015-05-29)
target rom version: 3.50.710.1
found large-zip header, file count: 8
processing file 1/8...
sending 'zip' (172319 KB)...
OKAY [ 10.833s]
writing 'zip'...
(bootloader) HOSD CL#761596
(bootloader) GPT is up-to-dated. [17408]
(bootloader) Perform pre-update
(bootloader) start@23
(bootloader) apppreload.img@BYPASS
(bootloader) aboot_signed.img@100%
(bootloader) cota.img@BYPASS
(bootloader) sbl1-8994-1.img@100%
(bootloader) sdi.img@100%
(bootloader) hosd_signed.img@100%
(bootloader) rpm-8994-1.img@100%
(bootloader) pmic-8994-1.img@100%
(bootloader) boot_signed.img@BYPASS
(bootloader) recovery_signed.img@BYPASS
(bootloader) adsp.img@BYPASS
(bootloader) cpe.img@BYPASS
(bootloader) rcdata.img@BYPASS
(bootloader) modem_st1.img@BYPASS
(bootloader) modem_st2.img@BYPASS
(bootloader) tz-8994-1.img@100%
(bootloader) hyp-8994-1.img@100%
(bootloader) pg2fs_ship_signkey.img@BYPASS
(bootloader) sensor_hub.img@BYPASS
(bootloader) tp_SYN3351.img@BYPASS
(bootloader) tp_MXM11876.img@BYPASS
(bootloader) splash1.nb0@BYPASS
(bootloader) radio.img@BYPASS
FAILED (remote: 90 hboot pre-update! please flush image again immediately )
finished. total time: 12.809s
preupdate done, rebooting...
resending command...
< waiting for device >
sending 'zip' (172319 KB)...
OKAY [ 11.119s]
writing 'zip'...
(bootloader) HOSD CL#761596
(bootloader) GPT is up-to-dated. [17408]
(bootloader) Perform pre-update
(bootloader) start@23
(bootloader) apppreload.img@BYPASS
(bootloader) aboot_signed.img@100%
(bootloader) cota.img@BYPASS
(bootloader) sbl1-8994-1.img@100%
(bootloader) sdi.img@100%
(bootloader) hosd_signed.img@100%
(bootloader) rpm-8994-1.img@100%
(bootloader) pmic-8994-1.img@100%
(bootloader) boot_signed.img@BYPASS
(bootloader) recovery_signed.img@BYPASS
(bootloader) adsp.img@BYPASS
(bootloader) cpe.img@BYPASS
(bootloader) rcdata.img@BYPASS
(bootloader) modem_st1.img@BYPASS
(bootloader) modem_st2.img@BYPASS
(bootloader) tz-8994-1.img@100%
(bootloader) hyp-8994-1.img@100%
(bootloader) pg2fs_ship_signkey.img@BYPASS
(bootloader) sensor_hub.img@BYPASS
(bootloader) tp_SYN3351.img@BYPASS
(bootloader) tp_MXM11876.img@BYPASS
(bootloader) splash1.nb0@BYPASS
(bootloader) radio.img@BYPASS
FAILED (remote: 90 hboot pre-update! please flush image again immediately )
finished. total time: 13.093s
preupdate done, rebooting...
resending command...
< waiting for device >
sending 'zip' (172319 KB)...
OKAY [ 11.106s]
writing 'zip'...
(bootloader) HOSD CL#761596
(bootloader) GPT is up-to-dated. [17408]
(bootloader) Perform pre-update
(bootloader) start@23
(bootloader) apppreload.img@BYPASS
(bootloader) aboot_signed.img@100%
(bootloader) cota.img@BYPASS
(bootloader) sbl1-8994-1.img@100%
(bootloader) sdi.img@100%
(bootloader) hosd_signed.img@100%
(bootloader) rpm-8994-1.img@100%
(bootloader) pmic-8994-1.img@100%
(bootloader) boot_signed.img@BYPASS
(bootloader) recovery_signed.img@BYPASS
(bootloader) adsp.img@BYPASS
(bootloader) cpe.img@BYPASS
(bootloader) rcdata.img@BYPASS
(bootloader) modem_st1.img@BYPASS
(bootloader) modem_st2.img@BYPASS
(bootloader) tz-8994-1.img@100%
(bootloader) hyp-8994-1.img@100%
(bootloader) pg2fs_ship_signkey.img@BYPASS
(bootloader) sensor_hub.img@BYPASS
(bootloader) tp_SYN3351.img@BYPASS
(bootloader) tp_MXM11876.img@BYPASS
(bootloader) splash1.nb0@BYPASS
(bootloader) radio.img@BYPASS
FAILED (remote: 90 hboot pre-update! please flush image again immediately )
finished. total time: 13.091s
preupdate done, rebooting...

Have superCID, unlocked bootloader and S-OFF.