Database Users

S4 Doesn't turn on after downloading recent update

Hi All,
I need your help. I downloaded the latest update for the S4 this morning after i clicked yes for the phone to reboot. It didn't turn back on. Everytime I try to turn it on, it vibrates but it doesn't show the logo. I also tried entering the recovery mode or download mode but there's nothing on the screen. I also tried removing the battery for several minutes and then tried the things i said above.
Is there any other way I can boot this or reformat my phone? Please help.
Thank you very much in advance

Same here.. I had the same problem.. I did try reset it and go to recovery mode, once on recovery mode, i can choose any option because it automatically goes back to install the update. And then after installation it stuck at the boot screen again and can't turn on. I had my phone rooted before but I already flash my phone back to stock. During the period where i root my phone i never install any custom ROM and whatsoever..

re: odin flash - JIG
katsumotoken said:
Same here.. I had the same problem.. I did try reset it and go to recovery mode, once on recovery mode, i can choose any option because it automatically goes back to install the update. And then after installation it stuck at the boot screen again and can't turn on. I had my phone rooted before but I already flash my phone back to stock. During the period where i root my phone i never install any custom ROM and whatsoever..
Click to expand...
Click to collapse
What I would do is go to ebay or online stores and buy a USB JIG it works perfect on Samsung Galaxy S4
and other android phones. The price is right too, anywhere from $1.00 to $5.00 including shipping.
Here is a link worth looking at:
https://www.google.com/search?q=andr...icial&tbm=shop
JIGS are made for issues just like the ones you and @lasallegreen are experiencing.
All you need to do with the jig is first remove the battery from your phone for
20 seconds and replace it, then plug the USB jig into the usb port of the phone.
Wait a couple seconds or so and you will see the download mode screen.
Unplug the usb jig and load/open odin and after putting the stock rom in the
pda slot in odin connect usb cable from phone to computer.
Make sure the [COM:xx] lights up in Odin and click START.
Once odin successfully flashes the official stock rom the
phone will again be in perfect condition ready to use.
Your phone is NOT hard bricked, but most likely it is soft bricked meaning that it can be fixed to
come back to life after Odin flashing the official Samsung S4 stock firmware/rom which you can
find and download from http://SamMobile.com by searching by the model number of your phone.
Good luck!

Will try this method.. Thank you very much for your kind reply.. Will let you know of the outcome..

katsumotoken said:
Same here.. I had the same problem.. I did try reset it and go to recovery mode, once on recovery mode, i can choose any option because it automatically goes back to install the update. And then after installation it stuck at the boot screen again and can't turn on. I had my phone rooted before but I already flash my phone back to stock. During the period where i root my phone i never install any custom ROM and whatsoever..
Click to expand...
Click to collapse
i was able to flash the stock rom using odin to see if that is the problem. I was successful in flashing but there's still nothing on my screen.

update: when i leave it for a few hours or so, there are times that the screen turns on and then it boots normally but if you reboot it's back to its frozen state. I hope someone can help me with this.

Flashing in Odin Fails after Flashing Latest Firmware

I wanted to update my modem so I flashed the newest Firmware with the July Security update - Firmware: G955FXXU1AQG5_G955FOXM1AQG5 which I downloaded from Sammobile.
Everything flashed fine. I then went to flash TWRP and it failed. I could not get it to flash no matter what I tried. I got a Fail error each time.
I thought I would try flashing the previouls firmware - and each time I tried to flash that I also got a fail error - and for grins and giggles I even tried to re-flash the new firmware again, just to see if it would work - and it failed each time again.
I am kind of freaked out. I cannot get anything to flash via ODIN and not sure what to try. OEM is unlocked - I have flashed firmware hundreds of times and never had this problem before - really kind of lost on what to try - Open to any suggestions? (I have already tried several different cables)
Suggestions?

Geekser said:
I wanted to update my modem so I flashed the newest Firmware with the July Security update - Firmware: G955FXXU1AQG5_G955FOXM1AQG5 which I downloaded from Sammobile.
Everything flashed fine. I then went to flash TWRP and it failed. I could not get it to flash no matter what I tried. I got a Fail error each time.
I thought I would try flashing the previouls firmware - and each time I tried to flash that I also got a fail error - and for grins and giggles I even tried to re-flash the new firmware again, just to see if it would work - and it failed each time again.
I am kind of freaked out. I cannot get anything to flash via ODIN and not sure what to try. OEM is unlocked - I have flashed firmware hundreds of times and never had this problem before - really kind of lost on what to try - Open to any suggestions? (I have already tried several different cables)
Suggestions?
Click to expand...
Click to collapse
Dude I already posted have a look before lol this will sort it out chill its fixable - https://forum.xda-developers.com/galaxy-s8/help/stuck-bootloop-flashing-aqg5-fix-t3636857

Nameless said:
Dude I already posted have a look before lol this will sort it out chill its fixable - https://forum.xda-developers.com/galaxy-s8/help/stuck-bootloop-flashing-aqg5-fix-t3636857
Click to expand...
Click to collapse
I tried what you said and it didn't work. I found that right now, I can flash in odin - but in order for anything to flash and not fail, I have to get into download mode from the phone after it is turned off. But now I can't turn off the phone.
Before I saw your post, I discovered that if turned my phone off completely, and then went into download mode I was able to flash in odin successfully. So TUrned off the phone., booted into download I reflashed the new firmware booted up fully and turned off my phone and booted to download and flashed TWRP. The flash worked. But I was not able to boot into recovery.
I am stuck on the samsung logo screen.
BUT , now I can't turn off my phone. If I could turn it off, I know I could get into download mode and I could flash the bootloader -But right now, anything I attempt to flash in ODIN Fails - I have to find a way to turn off the phone so I can get into download mode from the phone when it is turned off.
Is there any way I can force the phone to turn off? I can get into download mode - but I can't turn off the phone.

Geekser said:
I tried what you said and it didn't work. I found that right now, I can flash in odin - but in order for anything to flash and not fail, I have to get into download mode from the phone after it is turned off. But now I can't turn off the phone.
Before I saw your post, I discovered that if turned my phone off completely, and then went into download mode I was able to flash in odin successfully. So TUrned off the phone., booted into download I reflashed the new firmware booted up fully and turned off my phone and booted to download and flashed TWRP. The flash worked. But I was not able to boot into recovery.
I am stuck on the samsung logo screen.
BUT , now I can't turn off my phone. If I could turn it off, I know I could get into download mode and I could flash the bootloader -But right now, anything I attempt to flash in ODIN Fails - I have to find a way to turn off the phone so I can get into download mode from the phone when it is turned off.
Is there any way I can force the phone to turn off? I can get into download mode - but I can't turn off the phone.
Click to expand...
Click to collapse
Hi
Are you able to restart your device. If yes when it boot and vibrate press 3 button to go download mode.
Downgrade your bootloader or full firmware.
Best of luck

drparvez said:
Hi
Are you able to restart your device. If yes when it boot and vibrate press 3 button to go download mode.
Downgrade your bootloader or full firmware.
Best of luck
Click to expand...
Click to collapse
it doesnt work. Every time I try to flash ANYTHING in ODIN it fails. The ONLY way I will be able to flash the firmware is if I can get the phone to power down first - turn off completely - so I can boot into download mode after the phone has been turned off.
It is the only way I can get an ODIN Flash to work - otherwise, ODIN FAILS every time. If I could pull the battery that would do it - but I can't do that - and no 3 finger reboot combination works. I can get into download mode fine - but when I flash anything it fails.
THis happened yesterday and at the time, I was able to turn off my phone - but now, I can't get to to turn off - all I see is the samsung logo - but like I said, If I could power it down compleeley and then boot into download mode, I am confident it would work. Unless I can get this phone to power down, I beleive it is really bricked. Yikes!

Geekser said:
it doesnt work. Every time I try to flash ANYTHING in ODIN it fails. The ONLY way I will be able to flash the firmware is if I can get the phone to power down first - turn off completely - so I can boot into download mode after the phone has been turned off.
It is the only way I can get an ODIN Flash to work - otherwise, ODIN FAILS every time. If I could pull the battery that would do it - but I can't do that - and no 3 finger reboot combination works. I can get into download mode fine - but when I flash anything it fails.
THis happened yesterday and at the time, I was able to turn off my phone - but now, I can't get to to turn off - all I see is the samsung logo - but like I said, If I could power it down compleeley and then boot into download mode, I am confident it would work. Unless I can get this phone to power down, I beleive it is really bricked. Yikes!
Click to expand...
Click to collapse
No its not really bricked, even if you are seeing samsung logo, press bixby button + volume down + power button, it will reboot to ask you to enter into download mode or cancel to reboot, press volume up to enter download mode, I have done the same few moments and it works

Geekser said:
I tried what you said and it didn't work. I found that right now, I can flash in odin - but in order for anything to flash and not fail, I have to get into download mode from the phone after it is turned off. But now I can't turn off the phone.
Before I saw your post, I discovered that if turned my phone off completely, and then went into download mode I was able to flash in odin successfully. So TUrned off the phone., booted into download I reflashed the new firmware booted up fully and turned off my phone and booted to download and flashed TWRP. The flash worked. But I was not able to boot into recovery.
I am stuck on the samsung logo screen.
BUT , now I can't turn off my phone. If I could turn it off, I know I could get into download mode and I could flash the bootloader -But right now, anything I attempt to flash in ODIN Fails - I have to find a way to turn off the phone so I can get into download mode from the phone when it is turned off.
Is there any way I can force the phone to turn off? I can get into download mode - but I can't turn off the phone.
Click to expand...
Click to collapse
Do what I said flash aqf7 BL and as soon as you hit start to flash it hold down the 3 button combo and it will take you straight back to download mode. When it does this hit start straight away again

asif4self said:
No its not really bricked, even if you are seeing samsung logo, press bixby button + volume down + power button, it will reboot to ask you to enter into download mode or cancel to reboot, press volume up to enter download mode, I have done the same few moments and it works
Click to expand...
Click to collapse
I appreciate your comments but you didn't read what I posted.
I have not been able to flash anything in ODIN - I can get into download mode, but every flash failed. I have used every ODIN version and changed USB CORDS>
But I have good news. I kept messing with tings and I was able to finally get my phone to power off. DOn't ask me how because I can't repeat it - but anyway - I did get the phone to turn off - then I went into download and flashed the June Firmware (with June Security Patch)
Flash worked fine - I have since installed TWRP and am now flashing BATMAN ROM - wow - what an adventure..
I learned a lesson thought - seems like the July Firmware has something that doesn't like TWRP at all - I could not flash twrp while on that firmware - so I am back on the June firmware and will do my best not to let that happen again.
Thanks for your help - to all who tried. Thanks

Use smart switch to recover. Since you are locked in download mode, smart switch from samsung works. I did it yesterday, since odin failed whatever i tried to flash. And after you recover from smart switch, use odin again to flash newest firmware. But dont flash TWRP until is it updated.

ole12 said:
Use smart switch to recover. Since you are locked in download mode, smart switch from samsung works. I did it yesterday, since odin failed whatever i tried to flash. And after you recover from smart switch, use odin again to flash newest firmware. But dont flash TWRP until is it updated.
Click to expand...
Click to collapse
I did try Smartswitch (before I found another fix) when when I attempted Smartswitch, when I connected my phone to my PC when it was in download mode, Smartswitch gave me an error that said it did not recognize the device I had connected.
I actually don't know how I did it - but I was able to eventually get the phonen to power down. When it had powered down completley - I booted in Download mode and this time I was able to flash the Older Firmware which ultimately fixed my problem. Thanks anyway for the tiip

Geekser said:
I did try Smartswitch (before I found another fix) when when I attempted Smartswitch, when I connected my phone to my PC when it was in download mode, Smartswitch gave me an error that said it did not recognize the device I had connected.
I actually don't know how I did it - but I was able to eventually get the phonen to power down. When it had powered down completley - I booted in Download mode and this time I was able to flash the Older Firmware which ultimately fixed my problem. Thanks anyway for the tiip
Click to expand...
Click to collapse
Hey guys,
I'm with your same problem..
Tryied all odin fails every time...
I tryied Smartswitch, and fail it to
I can't find AQF7 in the forum !! :-/

AngelOfBlood said:
Hey guys,
I'm with your same problem..
Tryied all odin fails every time...
I tryied Smartswitch, and fail it to
I can't find AQF7 in the forum !! :-/
Click to expand...
Click to collapse
I will upload it to GOOGLE DRIVE and will add a link here as soon as it is uploaded. Hang on ...

AngelOfBlood said:
Hey guys,
I'm with your same problem..
Tryied all odin fails every time...
I tryied Smartswitch, and fail it to
I can't find AQF7 in the forum !! :-/
Click to expand...
Click to collapse
Use https://www.sammobile.com/firmwares/ or https://forum.xda-developers.com/galaxy-tab-s/general/tool-samfirm-samsung-firmware-t2988647

AngelOfBlood said:
Hey guys,
I'm with your same problem..
Tryied all odin fails every time...
I tryied Smartswitch, and fail it to
I can't find AQF7 in the forum !! :-/
Click to expand...
Click to collapse
Sorry it took so long, but here is a link yoiu can download from GOOGLE DRIVE if you still need it - (it is faster from GOOGLE than from those other links) Good Luck my friend.
AQF7 FIRMWARE DOWNLOAD

Sjant said:
Use https://www.sammobile.com/firmwares/ or https://forum.xda-developers.com/galaxy-tab-s/general/tool-samfirm-samsung-firmware-t2988647
Click to expand...
Click to collapse
Geekser said:
Sorry it took so long, but here is a link yoiu can download from GOOGLE DRIVE if you still need it - (it is faster from GOOGLE than from those other links) Good Luck my friend.
AQF7 FIRMWARE DOWNLOAD
Click to expand...
Click to collapse
It worked guys !!
Not at the first time... They give it to me fail again, but I do it fast again after they restart then it worked !!!
Thank you so much

AngelOfBlood said:
It worked guys !!
Not at the first time... They give it to me fail again, but I do it fast again after they restart then it worked !!!
Thank you so much
Click to expand...
Click to collapse
Glad to hear it - I had problems too - the only way I could get a successful flash in ODIN was to first turn off my phone completely - then boot up into Download mode and then flash in ODIN. the only problem was when the phone is in a bootloop or frozen on the Samsung Boot Screen - it is impossoible to turn of fthe phone. I got lucky. It finally powered off on it's own. Then I was able to flash in odin.
Glad you got it fixed too.

Geekser said:
Glad to hear it - I had problems too - the only way I could get a successful flash in ODIN was to first turn off my phone completely - then boot up into Download mode and then flash in ODIN. the only problem was when the phone is in a bootloop or frozen on the Samsung Boot Screen - it is impossoible to turn of fthe phone. I got lucky. It finally powered off on it's own. Then I was able to flash in odin.
Glad you got it fixed too.
Click to expand...
Click to collapse
I cannot turn it off too.
There's a trick...
All the time you enter in Download mode, and hit Start in Odin, the Odin says "FAIL" and the phone automatic reboot.
The trick is..
When in "Download mode" Start and at the same time press and hold "Vol Down + Bixby + Power".
Odin says FAIL and it will restart the phone automatic.
Press faster and hold "Vol Down + Bixby + Power" to go again to "Download mode".
Press Start in Odin and be prepared to press and hold at the same time "Vol UP + Bixby + Power".
Odin will start to transfer the files... and after that the phone reboot again faster, just press and hold one more time and faster "Vol UP + Bixby + Power".
TWRP will start !

Please help, S4 does't start or go to recovery mode

Hi all,
I have a weird problem with my Galaxy S4 (i9505) as follows:
-The screen was broken, then replaced the screen and worked for fine so I upgraded the phone to the offered 5.0.1 OS.
-It worked fine for two days, and then suddenly turned off, and kept stuck on Samsung Logo.
-It only could go to Download mode, but never to Recovery mode.
-If connected to the wall charger, it keeps vibrating and displaying the battery symbol alternatively for ever.
-I tried every all the tricks I could find on the forums such as
----Using a new battery
----Writing the official firmware 4.4.2, 5.0.1, recovery firmwares (4 files AP, BL, CS, CCS), all completed successfully.
----Tried PIT files (disparately reset NAND).
-It kept showing "Memory Booting ..." message either when starting normally or with Recovery mode.
-Installed TWRP (latest) and then it showed "RECOVERY BOOTING ...", "RECOVERY IS NOT SEANDROID ENFORCING", " Set Warranty Bit : recovery".
-Lastly installed official firmware 4.4.2 and again showing "MEMORY BOOTING ...".
Your help is tremendously appreciated.

Also, I've noticed that I can go to the download mode only by pressing (Power + Vol Down) buttons, without the need to press the Home button, does that mean that the Home button is already pressed all the time (could be a faulty screen?).

I have an s4 sgh-i337m that will also go into download modem by only pressing volume down and power. The phone does function properly and I can get into recovery without any issues.

audit13 said:
I have an s4 sgh-i337m that will also go into download modem by only pressing volume down and power. The phone does function properly and I can get into recovery without any issues.
Click to expand...
Click to collapse
Thanks audit13, now the possible home button issue has been eleminated.
Any other suggestions?

Have tried flashing the stock rom with Odin 3.07 as a single tar file in the pda slot and performing a factory reset before letting the phone both for the first time?
When booting to recovery, are you letting go of the power button after the phone starts to boot?

Yep, I did all possible firmwares 5.0.1, and 4.4.2 either in one file or in 4 files, also I've tried every possible combination but didn't let me into Recovery mode.

Sounds like there may be something wrong with the phone's internal memory.
Only thing I can suggest is getting the phone flashed via jtag.

audit13 said:
Sounds like there may be something wrong with the phone's internal memory.
Only thing I can suggest is getting the phone flashed via jtag.
Click to expand...
Click to collapse
Happy to do anything in this stage, any guidelines about this jtag (never used before)?.
Thanks a lot

You'll have to take it to a cell repair shop to flash it.

Bricked S8s after software update.

Hi. Browsed for ages and always come here for answers.
Here's my problem.
2x S8s. SM-950f.
Updated to most recent software through software update. Both phones were glitchy and crashing and just generally irritating after.
Factory data reset etc. This did not resolve the problems, also led to one of them having issues with FRP (annoying)
Used Odin to try and flash the latest firmware (from sammobile, UK BTU) after flashing both, they reset and powered on. Got stuck at the S8 screen.
Restarted then both were at the "an error occurred during update" screen.
Managed to get back to download screen. Re checked the software and model numbers, even that the bootloader was the correct version etc. All was fine.
Connected to Odin, shows that it is connected, but nothing happens when clicking start.
Now after attempting that, both phones will not power on.
(One will when placed on the wireless charger, but just sticks at S8 screen) and download mode or reset screen can not be accessed. So, not exactly happy. And totally out of ideas
Any suggestions, beyond taking it to a shop to see if anyone can help.

yes .....dont tuch the phones for 24 hours let the battery die ...it will...connect to pc and then try download mode....u may need to press combination for like 1 minute to get to download mode....flash twrp reboot directly into it when odin says successfully .....wipe system data ....dont turn on phone download any custom rom flash and enjoy.....it will trip knox but worth than getting a new board....

Okay, will give that a try.
TWRP?

TWRP install
https://dl.twrp.me/dreamlte/twrp-3.2.3-0-dreamlte.img.tar.html: Download link for twrp SM-G950F (dreamlte)
Just said, wait until your device powers off due battery insufficience. Plug cable and hold at the same moment vol(down)+bixby+power. Then press vol(up) at the warning screen to proceed to odin mode. Let it charging a while like 1 h. Then unplug it and plug it to your pc. In Odin select ap the previous downloaded file. Take your mobile in your hand. With one hand, prepare your fingers to vol(up)+bixby and with the other hand start the flashibg process. Be careful, and take your hand directly from the mouse if you clicked start in odin, and position your one finger to power button, but dont click. If odin start pass, press immidiately the buttons (vol(up)+bixby+power) and let it to start into recovery. If you arrived to recovery, reply to us if not search for help!!!
Good luck
memreb

Still trying to get them on. Powered on to download mode but only for a couple of seconds and switched off again.

Can't get them to power on. Buggered

simonboyle said:
Still trying to get them on. Powered on to download mode but only for a couple of seconds and switched off again.
Click to expand...
Click to collapse
i have the same issue with my s8 but when i boot in download mode the screen goes black but if i press volupe up it connect to odin with black screen you shoud give it a try

Will try that

Okay, downloaded TWRP, can get phone calls nected to Odin but when I extract TWRP it doesn't give a valid file type.
Am I being dumb.
No files appear that Odin will recognise.
Also just shows as "recovery" no .tar or anything

Ignore above. Corrupted download.
Sorted.
Now when flashing TWRP is gets to a fail due to
"Complete (write) fail

Hi you should try flashing official firmware

itac47 said:
Hi you should try flashing official firmware
Click to expand...
Click to collapse
The point of the thread us that I am.unable to do that.
So kinda useless post buddy.
Read the OP.

Anyone want two bootlooped S8s? Hahahaha

simonboyle said:
Anyone want two bootlooped S8s? Hahahaha
Click to expand...
Click to collapse
Not sure what stage your at and maybe some more useless ideas
1. Trying to flash twrp is kinda of useless if you can't get into your system need oem unlock for that.
2. Have you tried taking out Sim card and SD card and reboot.
3. If you can at least boot try smart switch as it has a emergency recovery option.
4. Trying rebooting in safe mode.

All been attempted

Odin flash failed, stuck in Emergency Recovery screen, cannot turn off.

I was going along ok until I made the fatal error of transferring the Magisk patched file to PC via MTP instead of taking the time to re-learn adb, which must have corrupted it. Thus predictably Odin hung and I am in trouble.
Where I am stuck is being unable to turn the phone off to come back in download mode to start over with stock firmware. I have been unable to find any secret button presses, and the battery doesn't seem to want to die leaving me with an $800 paperweight.
I did search around for this first and didn't find any real answers. Has anyone found an effective solution to this problem? Thanks.

fastzombies said:
I was going along ok until I made the fatal error of transferring the Magisk patched file to PC via MTP instead of taking the time to re-learn adb, which must have corrupted it. Thus predictably Odin hung and I am in trouble.
Where I am stuck is being unable to turn the phone off to come back in download mode to start over with stock firmware. I have been unable to find any secret button presses, and the battery doesn't seem to want to die leaving me with an $800 paperweight.
I did search around for this first and didn't find any real answers. Has anyone found an effective solution to this problem? Thanks.
Click to expand...
Click to collapse
If Odin recognizes you device, you can flash firmware in emergency recovery.

Cindysmith0994 said:
If Odin recognizes you device, you can flash firmware in emergency recovery.
Click to expand...
Click to collapse
Thank you, but the PC won't recognize the device. What does happen is the emergency recorevy screen tries to come up. I tried starting in download mode with bixby+vol down then USB. I did get the battery low enough where I don't get the teal screen of death anymore, perhaps it is too low for USB to work? What I was hoping for was the charging animation but no luck. Surely this is just a software problem and there is a way out.

fastzombies said:
Thank you, but the PC won't recognize the device. What does happen is the emergency recorevy screen tries to come up. I tried starting in download mode with bixby+vol down then USB. I did get the battery low enough where I don't get the teal screen of death anymore, perhaps it is too low for USB to work? What I was hoping for was the charging animation but no luck. Surely this is just a software problem and there is a way out.
Click to expand...
Click to collapse
Did you try getting into recovery and perform a data factory reset and then see what happens?

Just load the stock firmware BL, Ap, cp and home csc into Odin if you see emergency teal screen. The emergency screen will start loading
Black screen ....Perhaps your battery is dead?

Thank you all for the replies. I had let the battery get low in a misguided attempt (based on advice elsewhere) to get it to shut off. I had to let it charge a while for it to wake up enough for PC to see it. Then I was able to flash in Emergency Recovery mode.
Thank you for the help.

fastzombies said:
Thank you all for the replies. I had let the battery get low in a misguided attempt (based on advice elsewhere) to get it to shut off. I had to let it charge a while for it to wake up enough for PC to see it. Then I was able to flash in Emergency Recovery mode.
Thank you for the help.
Click to expand...
Click to collapse
Glad you got your device up and running ?

Maybe someone can help me. I seemed to have borked my phone. I kept getting "Google is Stopping" with no way to fix it, so I tried reflashing my firmware in odin. After I loaded all the files and hit start, I realized I didn't untick auto reboot, so I tried aborting the installation and ended up with screen (I've had it before and got out of it by still flashing in Odin, but now, if I try to reflash firmware while in this screen, it's stuck on SYSTEM in odin.
Any help appreciated!

Try this
That is where I got stuck. Are you trying to flash stock or patched firmware? I had to start over with stock as I copied the patched via MTP instead of adb and it got corrupted.
I think what I did was unplug and reset Odin. Wait for screen to turn off, then make sure it is at least 80% charged. Then Bixby + Vol Down + plug in and you will go back to this screen. Then I was able to flash stock. I had to go so far as to re-lock bootloader and flash stock again since my "OEM Unlocking" was not just greyed out but missing. Since then I've had no time to try again, but at least I have a working phone.
This is my anecdotal procedure, can't say if it is the right or best one.

Hi All,
I was trying to flash the latest firmware for my device (G9750ZCU2ASG4) and during the odin process, my computer restarted which failed the update halfway through. I rebooted the computer, tried again, and it was trying to establish a connection for a really long time, so I disconnected my phone from the USB port on my computer, and held Power and Volume Down to try and force reboot the phone. I was going to try and go back into download mode to restart the process. My phone mentioned something about needing to do an emergency recovery, but I continued to hold down the power and volume down keys and then everything went black on the phone.
I've tried multiple USB cords, all of the button commands known for the device, and have even tried to perform the emergency mode recovery on my device, but it seems like it's in some sort of locked state; What I mean is the phone is stuck on a black screen. I can't "boot" into recovery or into download mode. The phone doesn't even vibrate when I hold the power button or power and down to try and force reboot it. Odin doesn't recognize the phone when I plug it into the computer nor does the device manager on my windows computer.
Does anyone have any experience with this sort of issue or any idea of what else I can do to try and get into download mode to flash my firmware again? All help, suggestions, or comments regarding this are much appreciated.

Sounds like the battery is dead

Hi Dude, I am struggling with the same problem, read this post and it came to me, had to come back and give you the solution.
Press bixby+volume down, IMMEDIATELY after the screen goes off, hold volume up and down while connecting the USB cable super fast.
You have got like 10ms to do it
Otherwise it just goes back to the AVB FAIL screen

Ran into this issue, none of the above worked for me.
This is how I resolved:
1) Placed phone on wireless charging mat and let it boot to emergency recovery screen
2) Load TWRP into AP slot of Odin and leave the window open on your computer ready to flash
3) Connect phone to computer whilst it's on the mat and press start in Odin as soon as your device appears
It may fail a few times but if your quick you can install TWRP.
4) Now boot into recovery and let your phone charge to a reasonable level (above 20%)
5) Boot into Download mode and flash your desired rim via Odin