Develop Bugs

Boot problems - can't get to Tricolor, but boots to Android

Hello all,
I've searched and found some things, but nothing that matches my problem.
HTC Kaiser, branded Swisscom. HardSPL, I don't remember the version. Trying to get to tricolor screen, no key combo works. Camera+reset w/stylus, camera+power, even the two soft keys to reinstall the rom in memory.
After pulling the battery (and waiting more than 5 minutes) and inserting again, pushing the power button turns on the green LED, but goes no further, even after waiting up to 10 minutes. Pulling the battery, then plugging in the USB charger (without presses the power button) will flash a white screen after 7 seconds, then a pause of another 10 seconds, then the phone boots in to Android (again, without pushing the power button, just plugging in the USB cable.
Once in Android, everything works (except the factory reset, it just hangs forever). I need to install WM 6.5 ROM.
Tried the KAISDIAG.NBH and the 329 HardSPL recovery, but no reaction and still can't get to the tricolor.
One last piece of information, when I plug in the USB data cable, the phone flashes the "USB connected" message, and then repeatedly flashes it again every 3 seconds. The computer makes the USB connected sound, but no communication and the KaiserCustomRUU.exe can't see the phone.
Any suggestions to get to the tricolor? It unusual to turn on the phone by just plugging in the USB cable.
Thank you and great work.

Try power+camera+stylus pressing the reset.

A while back the charging behaviour was changed, so that now plugging in a charger, or usb, boots the phone, ( previously we could not charge if it was switched off).
Your problem of `losing` the bootloader has been seen before, but is rare, and seems to have no definite cause, the last time I remember seeing it turned out to be a faulty camera button.
Sent from my HTC Dream using Tapatalk

Thanks and one more question
Thanks Zenity.
I'll continue working on it. One quick question, is there a command in Android to force a hard reset or to the boot loader?

Camera Button
Ok, after searching more (due to Zenity's suggestion) and reading other threads, I don't think it's a faulty (Fawlty?) camera button.
Somehow, the phone takes along time to boot, and must use some info from the bootloader, as it loads Android.
But all attempts to get into the bootloader fail. I can't establish communication by USB, but I think I will focus my efforts there. I've pushed and help all the buttons in different combinations for too long.
I'll let you know, and thanks again!

Ok, done some research into way to detect that the camera button is functioning, ( since this button is vital in getting the bootloader), no luck yet, but research continues, looking at remapping the camera button using atools, just so i can get a response of some sort, ( normally the camera button does nothing in android, it's unmapped).
Edit: nope, atools won't help, won't let me remap the camera button.

Atools-keymapper remap the key only in the android GUI not in kernel so any change doesn't effect directly the kernel.

Yeah, realised that, just thought there might have been an easy way of diagnosing the camera button, to see if it was at least functioning, but if it's not enabled at kernel level then it will be difficult to test without disassembly and getting a meter on it.
Sent from my HTC Dream using Tapatalk

Update - Android.process.acore
Hey all, still trying to connect by USB to use the CustomRUU tool. Now when I plug in the USB, I get a repeating 'Process android.process.acore has stopped etc".
when I click force close, it pops up again and again.
Pulled the battery, and rebooted. Now it boots repeatedly, it shows the splash screen, right when it should go to the Android home screen, it reboots.
Any ideas? Thank you!

probable that the FC and subsequent reboot corrupted the data partition, which is known to happen when the device shuts down unexpectedly.
You can try a 'fix permissions', and 'clear dalvik cache', but normally it takes a wipe and re-install of the system, you may get away with not clearing data, but it's often safer to go for the full wipe of system and data.

MTCB headunit does not get passed boot screen

Hello everyone, I am new to the forums, so apologies if this is posted in the wrong section.
I purchased an android headunit, MTCB type, but immediately after installation unit does not work.
Unit is 1024x600 with rk3188. it is one of the custom fitted units to a civic, has volume knob (power button when pushed), tuning knob (also a button when pushed), disc eject button, back button, and small recessed reset button.
I am able to boot in recovery mode, and have tried everything from that menu..
I have installed different 5.1.1 firmwares, tried different MCUs, and nothing seems to work.
I always have the same problem where it displays the Andorid Auto Lollipop 5.1.1 screen, button lights are on, then it turns off.
Only way to reboot is to hold the reset and power button and boot into recovery mode.
When I connect to my laptop, it recognizes it as a rockchip device, but I am not sure if there is any troubleshooting I can try with PC connection.
On one occasion, after installing new firmware it went passed the lollipop screen and displayed the Android boot animation but hung at that screen forever.
After reboot, same issue persisted.
I have been unable to find my factory MCU, & manufacturer is of no help. My unit is: MTCB-KLD-V2.08
Installing the original MCU for 2.08 is the only thing I havent been able to do, because I can't find a download for it, so if someone has a link, that would be appreciated.
Otherwise, is this issue a factory defect, or is there some type of sleep mode it's entering? Any help would be greatly appreciated.

try wiping the data 3x and then reflash the update.img and mcu.img
the first boot will take 20mins or so (seems like it is forever)

Problem with booting G4

Hello, I would like to first tell you the story my LG G4 has gone through and then I tell you the error.
So, at first my phone was working absolutely properly. I accidentally deleted some pictures and to do a recovery, I had to root it. And rooting would be useful for later so why not do it?
So I first unlocked the bootloader through the code from the LG site. After unlocking, the phone reset (because it would be just too good to make some memory changes and nothing more.) But allright. Then I was ready to root. I just booted the phone, everything was fine. I unlocked the developer mode and opened ADB. I rebooted to recovery through
Code:
adb reboot recovery
I was expecting to see some menu with buttons (but that would be just too good). However, I saw just android with a red triangle in the middle. Nothing more. No response to buttons, nothing.
So I thought. Allright, let's boot into recovery using hardware buttons (vol down + power) at startup. Unfortunatelly, it seemed like there is no such mode System just normally booted (and that was just after bootloader unlocking. Recovery mode goodbye.).
I tried to send commands to the phone using diagnostic port. Unfortunately, it responded by FAIL to every command.
I reboot to bootloader and booted an image: "boot-em.img" (from here: google: how-to-root-lg-g4-on-android-6-0-marshmallow-20a20b-firmware. I'm a newbie here. thx for understanding.)
After that the console uploaded the image and booted successfully. Then, however, system started to boot up and was endlessly booting (LG boot animation) till the battery was critical.
I was able to access the EMI number through volume-down button and volume-up button pressed simultaneously.
I was also able to access some factory-reset dialog by holding volume-down and pressing power-button several times. I choosed to reset everything and then accepted it with one more 'are you sure dialog'. System rebooted and was stucked in the LG boot animation.
Then I got to download mode, since recovery mode was lost in hell. Through LG-UP I flashed the original KDZ firmware and everything got back to normal, but recovery mode was still inaccessible through the hardware buttons. I got through the process of setting everything up, getting developer, rebooting to bootloader and I booted TWRP.
TWRP loaded and it responded to double-tap on screen to wake it up. I just checked the menus and let the phone sleep.
After several hours I went back to the phone and double-tapped on display. Nothing. Phone was not responding. I pressed the power button and the phone restarted (I think. It either restarted into the system or was not responding to power button.)
So I got to the system and again rebooted to the TWRP (through fast-boot). I tried to back-up one partition to the disk. During the process phone had turned the display off. So I double tapped. Nothing. I removed the SD card and the phone woke, saying that back-up process was not able to complete. Suddenly it stopped responding to double-tap. It woke up through an interrupt. I re-inserted the card, successfully backed-up the partition to the SD-card and I left the phone laying on the bed plugged in the charger. It stayed that way for 4 hours or so, doing nothing. All of a sudden, a yellow screen was there, (and that's a screen of absolute death that was never supposed to come. Little I knew.) saying that an unexpected critical error happened and to do a memory dump, insert a cable, set up some communication (I don't remember what it was, didn't take a picture of it.) and it could send the memory dump to PC or somewhere. I thought to myself. So, the application is not so stable after all. It said that to reboot just press the power button or something.
And now the problem comes:
The first start: Bootloader booted, LG animation went on and finished. The starting up apps dialog came rolling. Then, system restarted.
The restart: Bootloader booted, LG animation went on and freezed. Then, the phone restarted.
Second restart: The same thing as the first one.
Fourth restart up till now: Bootloader tries to boot and restarts before the LG animation.
I got to download mode and it restarted even there. After re-inserting the batterry I can sometimes get to the Firmware Update window and communicate. There I flashed the official firmware again.
No success, as if I didn't even do it. It restarts before the animation.
Can I do anything with the phone? Hopefully I can. No hardware problem occured (except for a situation where the error could fry the wires inside the mighty System On Chip.)
For the software state I cannot even tell but I might say it's cooked just wrong. That's why I came here.
I know I did some pretty stupid steps. But the error was not done by me. It worked fine and after the yellow screen which came by itself, it just (some bad words).
Thanks for replies.
Phone: LG-G4 H815, European market

Solution
So, I was looking around and believe it or not, this problem disconnected the pins on the motherboard's snapdragon 808.
I think this happened: The device, although it was heated many times during its life, it withstood that so far.
However, a longer run of the TWRP had finished it off. Memory got disconnected while running and it threw a yellow-screen.
Pins got disconnected and from then on it was just a standard common LG bootloop issue.
The continuous process of dying (First it partially loaded, then only animation, then nothing) is explained by this fact that the pins were so-so there and a couple of reboots just got it totaled.
Temporary fix:
Pre-heated the memory chip to 250°C using Hot-Air gun. After 18 seconds at this temperature I pressed the memory on top of the snapdragon down to the board while cooling.
Then I added a little metal square on the metal part that is covering the system on chip. This part is over the SOC where before there was just some tape.
This can work for several days in sleep mode or a couple of 'heat-demanding' operations on the phone.
Permanent solution should be to reball the memory chip on the snapdragon. That's my next step.

Help with bootlooped mi5s :(

Hi.
I have a Xiaomi mi5s 64/3 GB in an endless bootloop. Here are the details:
The phone is:
rooted
bootloader unlocked
developer mode enabled
internal storage *not* encrypted
no MIUI account activated
USB debugging on
running the last EU MIUI 9.x development version (don't remember the exact version) with Android 7.0
has TWRP 3.2.1.0 and supersu 2.82
no password is set for unlocking the screen etc.
For some unknown reason the phone suddenly rebooted yesterday and got into an infinite bootloop cycle. I haven't changed any roms recently or done any such flashing. My google play automatic updates were disabled, but a few days ago I manually updated all the apps.
The only odd thing that happened prior to this bootloop, was that when shooting some photos with the google camera mod (same one I've been using for the past few weeks), 2 images were saved as corrupt unreadable files. But that happened a few hours before the bootloop suddenly started.
The current status is:
1. I cannot turn the power off (tried holding the power button, or power button + vol up and down for a very long time --> nothing).
2. I cannot enter recovery mode using vol up + power.
3. I cannot enter EDL using all 3 buttons.
4. If I hold volume down, it enters fastboot but automatically exits from it within 4 seconds (ADB and miflash cannot detect the device in this short period of time). holding the volume down button for a long time has a repating enter-exit-after-4-seconds from the fastboot graphics.
I waited until the battery was completely dead, than started charging it and the status described above was unchanged.
QUESTION 1 - restoring the internal data is my number one priority - does it seem possible here?
To be exact: I want the DCIM folder with the photos+ videos. What should I try now?
QUESTION 2 - I ordered an EDL cable, but am unsure if it supported for my MIUI version. if the EDL cable works, can I force the phone to enter recovery mode from within EDL?
If so - I guess I can copy the internal data to an external USB OTG flash drive I have (that works well with the phone).
If my data is restored, I will then move onto trying to reflash the phone, but at this point this is the least of my worries...
Thanks all.

Anyone?

Maybe it's a problem with the button? I would disassembly the phone and check the hardware.

bedson87 said:
Maybe it's a problem with the button? I would disassembly the phone and check the hardware.
Click to expand...
Click to collapse
I don't know - the buttons don't seem like they are stuck in any way. When I push them, they click back out as usual.
Update - I created an EDL flash cable by stripping the cable gently, exposing the green and black wires, and looping them together - connecting this cable to the phone didn't help either.
Maybe I need to wait for the battery to die so the phone will turn off, connect this cable to the phone, keep the power button pressed while I connect it to the usb port in my PC... what do you think?

I have the same problem with mi 5s which started after update. Don't know what to do.

Took the phone to a local lab - it was all due to a faulty power button module.

Question S21 FE - endless bootloop and download mode/recovery not working (properly)

Hello,
my wife got a S21 FE (SM-G990B/DS VD2). Yesterday it started to reboot over and over out of a sudden, showing the samsung logo first, followed by the knox logo, then shutting off and on again. Tried several guides to enter Recovery or Download Mode. The only thing that worked was entering download mode by pressing Vol up, down and power while a USB-Cable is plugged in, but as soon as i press the vol up button to pass the "warning screen", it shows some phone specs for a couple of seconds, shuts off and starts bootlooping again. After some hours, the phone once entered recovery mode when it lied next to me for about an hour. Tried to wipe cache, but just got an error I can't remember right now. Hoped it fixed itself when it made it to recovery and just rebooted to see if it works again, but then it just keept bootlooping again.
Since then I couldn't figure out why it once booted to recovery on it's own nor why I can't force it to enter recovery by pressing vol up + on.
Still hope it's just a faulty update or bug, but feels very much like it's a hardware related issue. Replacing the phone won't be an issue, but I'd really want to save data on the phone as my wife didn't make any backups and really wants to keep the photos.
As I just found guides that included recovery or DL-Mode, which are both no valid options for my case, I'd be thankful for any ideas to fix the phone or at least gain access to files before replacing it.
So.. did anyone come across similar issues and found a solution to revive the phone or are there any "unpopular" ways to recover samsung phones out of this state?
Edit:
Turned off completely overnight, booted once to system, looped again and now it's working like nothing ever happened. Got no clue what caused it or why it is working again. Saved everything for the case it happens again.
Wouldn't trust that device anymore, but my wife wants to keep it.
¯\_(ツ)_/¯

I would just like to reply here and add my own potential fix and also would like confirmation that it would work.
So I have a SM-G996B in a boot loop which returns a 'fs_mgr_mount_all' error. Possible to reboot into recovery mode, cleared cache and restarted bootloader etc with the same boot loop. Powered off and connected to PC for Download mode for ODIN recovery but upon pressing volume up, it then restarts again so Download mode recovery is impossible.
I know however that Developer options and USB debugging was enabled on the device as well as unlocked boot loader. I was able to download the correct original stock OS based on the PDA , CSC and Android version.
I have then installed the latest ADB software on my PC and Samsung USB drivers.
By then rebooting into recovery mode, I have the option of 'Apply update from ADB'. I have then confirmed the device connects using the ADB devices command.
I would like to clarify one thing however. I want to keep the user data at all costs. By using the stock firmware and renaming as update.zip, will it use the HOME_CSC and not the CSC file? If not would it work if I open the zip and remove the CSC before re-zipping to make sure?
Thanks

Reebee said:
Hello,
my wife got a S21 FE (SM-G990B/DS VD2). Yesterday it started to reboot over and over out of a sudden, showing the samsung logo first, followed by the knox logo, then shutting off and on again. Tried several guides to enter Recovery or Download Mode. The only thing that worked was entering download mode by pressing Vol up, down and power while a USB-Cable is plugged in, but as soon as i press the vol up button to pass the "warning screen", it shows some phone specs for a couple of seconds, shuts off and starts bootlooping again. After some hours, the phone once entered recovery mode when it lied next to me for about an hour. Tried to wipe cache, but just got an error I can't remember right now. Hoped it fixed itself when it made it to recovery and just rebooted to see if it works again, but then it just keept bootlooping again.
Since then I couldn't figure out why it once booted to recovery on it's own nor why I can't force it to enter recovery by pressing vol up + on.
Still hope it's just a faulty update or bug, but feels very much like it's a hardware related issue. Replacing the phone won't be an issue, but I'd really want to save data on the phone as my wife didn't make any backups and really wants to keep the photos.
As I just found guides that included recovery or DL-Mode, which are both no valid options for my case, I'd be thankful for any ideas to fix the phone or at least gain access to files before replacing it.
So.. did anyone come across similar issues and found a solution to revive the phone or are there any "unpopular" ways to recover samsung phones out of this state?
Edit:
Turned off completely overnight, booted once to system, looped again and now it's working like nothing ever happened. Got no clue what caused it or why it is working again. Saved everything for the case it happens again.
Wouldn't trust that device anymore, but my wife wants to keep it.
¯\_(ツ)_/¯
Click to expand...
Click to collapse
Similar issue with same phone. In a bootloop after trying to root. None of the button combinations have worked for me, for the past several days.
Tried powering the phone off for the whole night.
When connected to the PC shows phone is in recovery mode via adb (blank screen though).
Want to know how to get into DL-mode, guaranteed.

Got to DL mode by pressing vol up + down + power + usb cable connected in PC and phone. However, couldn't do anything there, but maybe you can
Also, phone is still working and I still have no clue what was the problem and what fixed it.