[RECOVERY][TWRP 3.1.0-1] Galaxy Tab A SM-T350/355/357/550/555 SM-P350/355/550/555

[retiredtab]

Even with a JIG, nothing works...

You didn't say in a post whether you tried removing the battery cable.

 

[fire_qc]

What country do you live in?

A very small country call Canada it's just up north of USA...

 

[fire_qc]

You didn't say in a post whether you tried removing the battery cable.

No I didn't remove the battery yet.. For this tablet it's just annoying because I've to use a small tool to take it out all around the edges. But I'll do now to see if it can make a difference..

 

[retiredtab]

No I didn't remove the battery yet.. For this tablet it's just annoying because I've to use a small tool to take it out all around the edges. But I'll do now to see if it can make a difference..

I solved a couple of what I thought were bricked tablets just be removing the battery cable and leaving it out for 5 minutes. As long as the CPU/SoC gets power, it may be in a "funny" state. Even when the tablet is "powered off", it's not because it's always listening and waiting to react to the power button. Only a complete removal of the battery for a few minutes will the CPU/SoC be truly off.

It's the same as turning off your TV. When you "turn off" your TV, it's merely in standby mode waiting for the user to hit the remote control or press the on button. When you physically removing the TV's power cord from the AC outlet, then it's completely and truly powered off.

 

[fire_qc]

I solved a couple of what I thought were bricked tablets just be removing the battery cable and leaving it out for 5 minutes.

Removing the battery change nothing..

 

[retiredtab]

Removing the battery change nothing..

I'm afraid your only option is some sort of riff box or jtag programmer. You might want to try and contact your local makerspace or electronics group to see if anyone has such a tool. Check out the local universities or colleges?

I don't have any of those tools so sending the tablet to me won't help.

Flashing at any time has risks. When developing 17.1 for the SM-T350 I took the most risk out of anyone. I easily flashed over 100 builds to fix bugs, stuck at boot animations, etc. For 18.1, if it ever works, I can easily see another 100+ builds in the future.

 

[alecxs]

i am not sure, thought this device is Exynos chipset (although someone posted about Qualcomm). you can unbrick in (EDL) emergency download mode if you manage to short-circuit test points on PCB. that requires Qualcomm HS-USB QDLoader 9008 Driver, QFIL and proper Samsung signed factory loader (firehose programmer)
https://github.com/alephsecurity/firehorse
https://android.stackexchange.com/q...cant-go-to-recovery-mode#comment305555_224235

 

[fire_qc]

i am not sure, thought this device is Exynos chipset (although someone posted about Qualcomm). you can unbrick in (EDL) emergency download mode if you manage to short-circuit test points on PCB. that requires Qualcomm HS-USB QDLoader 9008 Driver, QFIL and proper Samsung signed factory loader (firehose programmer)

Can tell if it's a Qualcomm or something else.
Here the picture of it ..

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[retiredtab]

SM-T350 is Qualcomm snapdragon 410.

 

[retiredtab]

How to flash stock bootloader with Odin

To flash just a bootloader with Odin:

1. Extract the aboot.mbn file from the .tar.md5 ROM package, and (using something like 7-zip) create a .tar archive containing just that file.
2. Boot the T350 to Download mode and connect it to your PC with USB cable.
3. On the PC, run Odin. Click the "BP" button and navigate to the tar file you just created. Click Start.
4. Odin should flash the aboot.mbn and report "All threads completed (succeed: 1 / failed: 0)".
5. Reboot the T350.

I've attached a zip file containing T350XXU1BPI2_bootloader_only. tar and a README.txt file with explanation and instructions. T350XXU1BPI2 is the bootloader that's been shown to turn on the display panel.

As of this writing on Feb 7, 2021, there has been 18 downloads of the T350XXU1BPI2_bootloader_only. tar.

I downloaded 1 so that makes 17 people with the BOE. So far, 2 people have reported problems doing the above procedure. I assume, then it works for the other 15 people otherwise they would have said something.

We don't know why 2 people have problems flashing only the bootloader, but given this, you may want to flash the full stock rom so that the tablet behaves like Marshmallow stock in all respects. Then make sure it boots Marshmallow. If that is good, then flash TWRP 3.3.1, reboot into TWRP and flash your custom rom.

For the 2 that have reported problems, it's also possible that flashing the entire Marshmallow rom would have yielded the same results. Flashing, always, is risky.

 

[fire_qc]

I'm afraid your only option is some sort of riff box or jtag programmer. You might want to try and contact your local makerspace or electronics group to see if anyone has such a tool.

I send the tablet to a Tellution (local shop), the guy try Octopus JTAG box and got nothing!! He said the only option is to change the mainboard. If not using like a frisbee or coaster...
Incredible, flashing ABOOT cause this tab is completly DEAD...

Any ideas guys??

 

[retiredtab]

Any ideas guys??

Sounds like it's completely dead if a hardware JTAG box sees nothing.

 

[lpedia]

I send the tablet to a Tellution (local shop), the guy try Octopus JTAG box and got nothing!! He said the only option is to change the mainboard. If not using like a frisbee or coaster...
Incredible, flashing ABOOT cause this tab is completly DEAD...

Sounds like it's completely dead if a hardware JTAG box sees nothing.

The mainboard must have been physically damaged somehow, but flashing anything should not actually be able to do that kind of damage. These boards have a lot of protection built in, and in any case the process of flashing doesn't generate power conditions that the hardware can't handle.

There'd have to be something else involved, such as extreme overheating (from a faulty battery, for example) or exposure to high voltage (from a faulty charger, for example), or some component just choosing this moment to fail. The latter can certainly happen, more commonly when the device is new / hasn't been used much / has recently been repaired.

What's the history of this device? How long have you had it? Was it new when you got it? Was it working well with the Samsung ROM before this?

 

[alecxs]

@lpedia he messed up aboot. of course this caused brick. see post #641

please clarify: on which stage bootloader decides to enter 9008 edl mode?

 

[lpedia]

@lpedia he messed up aboot. of course this caused brick. see post #641

please clarify: on which stage bootloader decides to enter 9008 edl mode?

Does it mess up to the extent that a JTAG box can't do anything with it? I thought that would imply hardware damage ...

 

[alecxs]

don't know what JTAG box is or how this can even work over usb. JTAG (usually?) requires desoldering eMMC and expert knowledge / datasheet for the flash chip pin out. i doubt this can be done in regular service center. such service usually is more expensive than (used/second hand) replacement device.

according to this aboot implements download mode, so flashing via Odin can't work. But PBL will fallback to EDL if SBL failed to initialize aboot
https://alephsecurity.com/2018/01/22/qualcomm-edl-1

 

[lpedia]

don't know what JTAG box is or how this can even work over usb. JTAG requires desoldering eMMC and expert knowledge / datasheet for the flash chip pin out. i doubt this can be done in regular service center. such service usually is more expensive than (used/second hand) replacement device.

according to this aboot implements download mode, so flashing via Odin can't work. But PBL will fallback to EDL if SBL failed to initialize aboot
https://alephsecurity.com/2018/01/22/qualcomm-edl-1

The Octoplus JTAG box - the type used on this particular device by the service centre the OP took it to - claims it can flash/decode/repair a wide range of LG and Samsung devices, including these Galaxy tab models. The service centre tech said that box couldn't get anything from it, and that the only option was mainboard replacement. If that advice was correct, I do not see how this could have been caused by flashing aboot.

The PBL should bring up EDL mode if there's anything wrong with SBL or aboot, but on this device it didn't. It should have been possible to force it into EDL mode if the mainboard was functional, though, and presumably the service centre tried that before reaching for the JTAG box.

 

[alecxs]

presumably.. or they are just lazy and don't spend more than a minute for free

 

[alecxs]

btw just because a device model is listed, that doesn't necessary mean the box support flashing in edl mode. even if forcing edl via usb-pins is possible (xiaomi), still that requires factory loader (leaked from samsung internally). and JTAG over usb won't work. did service center even open the housing and short-circuit test point? if so, i am very interested where these test points located for this tablet

 

[alecxs]

@fire_qc the simplest approach is to wait a few weeks until battery died. your tablet most likely stucks in aboot because of the downgrade protection.

My brother gave this tablet to me, after service center "tried everything" and laying around for months. He was beeing told unable to flash via Odin.

I just flashed latest available ROM and he was very surprised. Only problem is locked bootloader now