PocketBook Basic 2 (PB614) unresponsive, always in FEL/flashing mode

[DoomsdayDog]

I'd been hoping for something obvious, but I have opened up the Pocketbook, unscrewed the board to reach the front buttons and verified that all buttons work. I tried holding down the power button and various combinations of the direction buttons, with and without plugging in to power.

What if the battery is dead/has been dead since day 1? I'd like to disconnect it from the board and check the voltage, but that will have to wait a while until I gather supplies.

[nhedgehog]

Have you tried to power up with the unscrewed mainboard?

[DoomsdayDog]

Yes, I tried:
1) press the power button
2) hold the power button for 10+ seconds
3) plug in to power via USB port and press power button
4) plug in to power via USB and hold power button for 10+ seconds

EDIT: and also pressed the left and right buttons together for 10+ seconds as one would for firmware update, plus pressed the direction pad buttons individually

[nhedgehog]

Out of ideas. Just to be sure: during your attemps with the buttons the internal SD was present again?

[DoomsdayDog]

Originally Posted by nhedgehog

Out of ideas. Just to be sure: during your attemps with the buttons the internal SD was present again?

Yes, I put the original SD with the original image back inside.

I'll try fiddling with the connection to the battery, there's nothing to lose I guess.

nhedgehog, thank you so much for your time so far. It's not really a problem if I can't fix this Pocketbook. I've always suspected I was given the broken e-reader on purpose, because I won the two Pocketbooks as a prize in school, and I guess it would have been nasty for the organisers to give the broken device to a kid who didn't also win a second, functional device.

[nhedgehog]

Still think it is a button problem or the soldering of the internal SD holder has lost contact. The second can be tested by booting the device up with a little pressure on the internal SD holder (not the SD itself).

Edit: I uploaded some images to illustrate. As you can see battery connector is clipped directly from above. To losen it you have to fixate the socket and carefully pry it loose starting on the cable side. Make sure to use isulated material to avoid shortcuts which can result in battery explosion.
See here too:
https://4pda.to/forum/index.php?show...ost&p=46218407

Edit2: The Russians replaced the screen without disconnecting the battery, this could be an options too to have a closer look at the buttons.

Edit3: More pics: https://4pda.to/forum/index.php?s=&s...ost&p=79397345

[DoomsdayDog]

Originally Posted by nhedgehog

Still think it is a button problem or the soldering of the internal SD holder has lost contact. The second can be tested by booting the device up with a little pressure on the internal SD holder (not the SD itself).

I just tried booting up the good Pocketbook without an internal SD, it exhibits the same behaviour as the broken one, even the output on my computer is the same (Allwinner Technology sunxi SoC OTG connector in FEL/flashing mode). Will fiddle with the SD some more.

Edit: Good device also refuses to boot if I remove the internal SD and place it in the slot for external SD.

[DoomsdayDog]

I have made a little circuit consisting of a LED and a resistor in series. On the good device, I am able to power the LED by touching wires to the (B+) and (B-) contacts on the board right below where the battery connects. On the broken device nothing happens.

[nhedgehog]

Faulty device:
1) LED tester lights up while connected to charger?
2) Have you tested if device boots up while connected to charger?
3) Have you tested if device boots up while connected to charger and slight pressure is put on the contacts of internal SD holder?

[DoomsdayDog]

Originally Posted by nhedgehog

Faulty device:
1) LED tester lights up while connected to charger?

Yes!
Edit: I would not be surprised if the battery is damaged due to deep discharge after 7 years with only 2-3 attempts to charge/power up the device.

Originally Posted by nhedgehog

2) Have you tested if device boots up while connected to charger?

Tested; it doesn't boot up if I press or hold power button.

Originally Posted by nhedgehog

3) Have you tested if device boots up while connected to charger and slight pressure is put on the contacts of internal SD holder?

No luck. I tried pressing down on the frame holding the SD card, and also pinching the left and right edges inward.

[DoomsdayDog]

More evidence that the faulty device is acting as if the internal SD card is not detected, I think: plugging the two devices to power (the good one with internal SD removed) produces the same sequence of noises coming from the A13 chip on both the good and the faulty e-reader (very subtle noises though, require a very quiet room to hear). The noises are very different and much louder when SD card is present on the good device.

[nhedgehog]

Can you check all the buttons with a tester (contact if pressed)?

[DoomsdayDog]

Originally Posted by nhedgehog

Can you check all the buttons with a tester (contact if pressed)?

I'm not sure how to do that. Could you link an example? [Explain like I'm five. Preferably with images...]

[kib]

Hello, I have the exactly same problem with another Pocketbook reader (PB631 Touch HD).
The display is frozen, after powering on the LEDs next to the button blinks shortly and that's all.
It must be a HW problem, not SW as I even received a testing image from Pocketbook that should just show SN of the device after booting, but it does not boot.
Also, there are no signals on the UART port.

I checked that all buttons work correctly with the multimeter.

[DoomsdayDog]

Hi kib, welcome to the party! The difference in my case is that the LED by the power button never blinks.

I was also curious to try UART next, how did you connect to the port?

P.S. could you describe how you checked the buttons, if you don't mind helping a noob?