Bootloop on Page after fastboot boot custom recovery.

[Anghirrim]

Hi,

I was playing around with my boox page and tried to unpack/repack the stock recovery to enable ADB.

And now, I am stuck in a bootloop I can't exit from.

What I did:
- Dumped stock recovery via EDL
- Unpacked the recovery.img using Magisk Tools (https://topjohnwu.github.io/Magisk/tools.html)
- Opened the ramdisk.cpio archive
- Edited the prop.default with the following options (found on the net, the goal was to enable adb on recovery):
- ro.secure=0
- ro.adb.secure=0
- ro.debuggable=1
- Saved my changes and repacked the recovery.img
- Booted into bootloader and ran "fastboot boot patched-recovery.img"

Now, I am stuck in a bootloop that I can't exit from.

Long pressing the power button does not help, trying to catch adb or fastboot neither.
Trying to boot under Qualcomm EDL 900e (holding volume buttons), no chance...

I also tried to change the active slot to b, but fastboot keeps waiting for a device.

I finally opened my Page and disconnected the battery. When I restart it.... still bootloop.


I need your help there.... what should I do?

I cannot find any reset point on the mother board, and I don't know where to look for the EDL 9008 test points.

Help

Motherboard pictures to come soon.

[Anghirrim]

Here are the pictures.

On the mother board, the battery connector is on the bottom left.

And the USB-C connector.

Suprisingly, the motherboard is labelled for the Boox Leaf 2 Pro.

[Renate]

Onyx has varied between very obvious (Poke3) to very obscure (Poke5) in the layout of UART and USB_BOOT ("EDL") test points.
I think the 5 points at the bottom of the big photo are the most probable.
But don't just go shorting things (unless you want to vaporize your device).
Do you have a DVM? Even a cheapy if it has "diode test".

[Anghirrim]

Originally Posted by Renate

Onyx has varied between very obvious (Poke3) to very obscure (Poke5) in the layout of UART and USB_BOOT ("EDL") test points.
I think the 5 points at the bottom of the big photo are the most probable.
But don't just go shorting things (unless you want to vaporize your device).
Do you have a DVM? Even a cheapy if it has "diode test".

Yep I do, one that makes a bip when current passes between the connection points.

Is this OK for you? It has the diode sign on the 2000ohm part.

[Renate]

Originally Posted by Anghirrim

Is this OK for you?

That's hard to tell, but let's go with it.

Device on.
DVM on 20 DCV --- (not ~)
Black lead on nice metal shield under the eMMC.
Red lead on each of the five points, measure the voltage. Write it down
Only for points that measure zero-ish (0.little):
Switch to "beeper mode" and measure again. Write it down.
What did you get?

[Anghirrim]

Originally Posted by Renate

That's hard to tell, but let's go with it.

Device on.
DVM on 20 DCV --- (not ~)
Black lead on nice metal shield under the eMMC.
Red lead on each of the five points, measure the voltage. Write it down
Only for points that measure zero-ish (0.little):
Switch to "beeper mode" and measure again. Write it down.
What did you get?

You mean like this?

[Renate]

Originally Posted by Anghirrim

You mean like this?

Yup. Yes, sirree.

[Anghirrim]

Originally Posted by Renate

Yup. Yes, sirree.

Ok, no risk to fry anything with 20V (just anxious lol)?

I'll try tomorrow, it's getting late here.

Thanks for the help!!

Edit: Ah no stupid me... It'll just measure how much goes through the DVM...

[Anghirrim]

Originally Posted by Renate

Yup. Yes, sirree.

Okay... From left (near the battery connector) to right:

Voltage (V): 0 | 1,8 | 0 | 1,8 | 0
Beep: / | / | B | / | /

I beep tested all point, I forgot you told me only the zero one. But only the square point in the middle beeps.

[Renate]

That looks good.
I'm not sure about your meter. Doesn't it give numbers too in "beep" mode?

So, here's what you do:
Device on, USB connected.
Meter in beep mode.
Black on tin
Red first on the far left point.
Hold the power button for 10+ seconds, release.
Watch for 05c6/9008 on USB.

Didn't work? Try again with far right point.

[Anghirrim]

Originally Posted by Renate

That looks good.
I'm not sure about your meter. Doesn't it give numbers too in "beep" mode?

So, here's what you do:
Device on, USB connected.
Meter in beep mode.
Black on tin
Red first on the far left point.
Hold the power button for 10+ seconds, release.
Watch for 05c6/9008 on USB.

Didn't work? Try again with far right point.

Ok, will try after work

When you speak about "black on tin", you're referring to the metallic shield, right?

And for the meter, I don't think it gives numbers while beeping.

[Anghirrim]

Side question, do you know if the faulty recovery caused that bootloop?
It's crazy that a "fastboot boot" query remains active even after a battery disconnection. I would have expected it to be volatile.

That being said, I ran the command twice. First, no error, but the device did not reboot. Second time, I had an error message (can't remember what), and it went into bootloop.

[Anghirrim]

Originally Posted by Renate

That looks good.
I'm not sure about your meter. Doesn't it give numbers too in "beep" mode?

So, here's what you do:
Device on, USB connected.
Meter in beep mode.
Black on tin
Red first on the far left point.
Hold the power button for 10+ seconds, release.
Watch for 05c6/9008 on USB.

Didn't work? Try again with far right point.

Okay, far right point did the trick.

I managed to boot into EDL 9008 mode and inject the loader.

However, I had to release the tips of my DVM and stop connecting the shield with the right point.

This resulted in loosing EDL and my computer started complaining about a device it could not recognize.

Now, to be able to flash something and stay in the EDL 9008 mode, should I find a stable way to keep those two points connected?

[Renate]

After it shows 9008 you shouldn't need to hold the probe any longer unless you reboot and want to go back to EDL.

[Anghirrim]

Originally Posted by Renate

After it shows 9008 you shouldn't need to hold the probe any longer unless you reboot and want to go back to EDL.

Hmmm weird... I'll have another try later then