Realme C21Y HardBrick - It says USB Device is faulty but disappears after 2 seconds - I can't enter download mode

[Luuukie]

I corrupted my phone's root/system/etc files and when I restarted it, it wouldn't turn on and got stuck on the realme logo. i hold my phone vol+ and - and power key and when the realme logo comes up, i release the power key, i think download mode opens, but it usb device is faulty for 1-2 seconds and disappears immediately, meanwhile in device manager it shows unknown device for 1-2 seconds and disappears. After 10-15 seconds there is a usb connection sound but nothing happens. I can send adb commands but I have to confirm the confirmation window but I cant.

Please help me, how can I fix it?

 

[Renate]

Does adb devices say "unauthorized"?
Are you sure that it's ADB and not fastboot or EDL that is appearing?
You can use usblog.exe to see what's popping up and down. Just run it.

 

[mvikrant97]

Install Unisoc/Spreadtrum drivers and then see if your device is recognised as a SPD USB device under device manager and let me know here

 

[Luuukie]

Does adb devices say "unauthorized"?
Are you sure that it's ADB and not fastboot or EDL that is appearing?
You can use usblog.exe to see what's popping up and down. Just run it.

Yes, I get the unauthorized message as below. If I can somehow authorize it, I will be able to enter fastboot mode and flash the stock rom.

Install Unisoc/Spreadtrum drivers and then see if your device is recognised as a SPD USB device under device manager and let me know here

Okay, I'm trying

 

[mvikrant97]

Install Unisoc/Spreadtrum drivers and then see if your device is recognised as a SPD USB device under device manager and let me know here

Please try a different usb port on your computer.

Don't use USB 3.0 port.

If nothing works then either the phone's usb is malfunctioning or your PC.

Don't use USB extension to connect your phone, plug directly to your computer port.

Also update your PC drivers using driver booster free software and then set restart and try again

 

[Luuukie]

Please try a different usb port on your computer.

Don't use USB 3.0 port.

If nothing works then either the phone's usb is malfunctioning or your PC.

Don't use USB extension to connect your phone, plug directly to your computer port.

Also update your PC drivers using driver booster free software and then set restart and try again

I updated with Driver Booster, no luck.
I only tried the front USB ports, do I need the back ones? There are 2 2.0 and 1 3.0 port on the front
The computer is new so I don't think it's defective, the phone is charging and I was using it before it went brick.

 

[Luuukie]

I also modified the boot file to install a new GSI and used the following guide.

Spoiler

First, you need to unlock fastbootd:

1. Download the stock ROM version 91: Download and extract the .pac file Link
2. Install the SPD research tool and drivers: GDrive
3. Open it
4. Click on the single gear icon
5. Select the .pac file of the stock rom
6. Wait until it loads
7. Click on the two gear icon
8. Find BOOT in the list
9. Right-click on the path next to it
10. Download here and select boot_r1.img
11. Click OK and then click the arrow icon
12. Turn off your phone
13. Press and hold Power + VolumeDown until you see the text "Downloading"
14. Release the buttons after seeing
15. Wait until you see the text "Passed"
16. Click on the Stop icon, disconnect your phone and turn it on
[/ISPOILER]

 

[Luuukie]

@leanord Can you help me?

 

[Renate]

The 0000/0002 is standard Linux goofiness when you enable USB gadget but you don't initialize anything or add any functions.
This often pops up during boot sequences. It means nothing. It does cause Windows to say "Invalid device".

The 22d9/2769 appears to be normal ADB and since you're getting "unauthorized" shows that everything is fine.

Are you in recovery or regular Android?
Stock recovery usually is ADB secure and you don't have the keys for it.

 

[Luuukie]

The 0000/0002 is standard Linux goofiness when you enable USB gadget but you don't initialize anything or add any functions.
This often pops up during boot sequences. It means nothing. It does cause Windows to say "Invalid device".

The 22d9/2769 appears to be normal ADB and since you're getting "unauthorized" shows that everything is fine.

Are you in recovery or regular Android?
Stock recovery usually is ADB secure and you don't have the keys for it.

I don't fully understand your question, but I have the stock recovery, I didn't install TWRP, and I installed dotOS 5.2 as GSI. I think I corrupted the fastboot, download mode boot files in the root files. I will take it to the service center, but if you have a solution, you can write, I don't want to give money.

 

[Renate]

It's gone to stock recovery and you don't have keys.
You need to try buttons to get it into bootloader (fastboot). Or did they disable that?

 

[Luuukie]

It's gone to stock recovery and you don't have keys.
You need to try buttons to get it into bootloader (fastboot). Or did they disable that?

It may have been disabled or because I corrupted system files.

 

[leanord]

Wanted? I came, to flash the phone, you do not need to press anything except the volume keys, the power button is only a catalyst, you need to hold it down until the screen goes out, and then just Keep the volume - and flash as usual, the main thing is to keep it immediately plugged into the PC with a ready-made flasher

 

[Luuukie]

What I have done:
1. The screen is off
2. I hold down the volume - and power button.
3. The phone vibrates and as soon as the realme logo appears, I plug the usb into the phone and release the power button.
4. The computer receives the message "USB Device not recognized, malfunctioning" and the unknown device is added to the device manager (It doesn't come anymore, I don't know what happened, I installed a lot of drivers.)
5. After 20 seconds, the USB connection sound is heard and the name of my phone is added to the "universal serial bus devices" section of the device manager.

 

[leanord]

What I have done:
1. The screen is off
2. I hold down the volume - and power button.
3. The phone vibrates and as soon as the realme logo appears, I plug the usb into the phone and release the power button.
4. The computer receives the message "USB Device not recognized, malfunctioning" and the unknown device is added to the device manager (It doesn't come anymore, I don't know what happened, I installed a lot of drivers.)
5. After 20 seconds, the USB connection sound is heard and the name of my phone is added to the "universal serial bus devices" section of the device manager.

Why are you doing it? You should sit in the flash driver, and not watch how the device is connected, Windows will not have time to see exactly what is connected until you start flashing

 

[Luuukie]

Why are you doing it? You should sit in the flash driver, and not watch how the device is connected, Windows will not have time to see exactly what is connected until you start flashing

SP Flash Tool doesn't see my device so I can't flash it. If you mean Fastboot, I can't get into it.

 

[Renate]

By the way, that font that's showing up in my UsbLog is UGLY.
I readjusted things, you can download a new copy that is prettier.

 

[Renate]

Oh, this is a Unisoc.
I know a lot about Qualcomm, some about Mediatek and almost nothing about Unisoc.
Surely there is some way to get this into Unisoc ROM bootloader mode?
There are either test points or you can disable the eMMC?
If you could pull recovery and mod ro.adb.secure=0 you'd have recovery with ADB at least.

 

[Luuukie]

Oh, this is a Unisoc.
I know a lot about Qualcomm, some about Mediatek and almost nothing about Unisoc.
Surely there is some way to get this into Unisoc ROM bootloader mode?
There are either test points or you can disable the eMMC?
If you could pull recovery and mod ro.adb.secure=0 you'd have recovery with ADB at least.

I'm sorry, I don't know that much. But if you tell me the steps how to do it, I can do it.

 

[Luuukie]

@leanord when installing GSI, I flashed boot_r1.img from your Realme C21Y GSI installation guide, did you disable fastboot or something?