A20-4G : no boot - red led and nothing else

[mascaret]

Hi there!

Beware the newbie (no savvy-tech)..
Burnt a debian freedombox built for olimex A20.
Successfully booted and worked from the start.

Unplugged without properly shutting down the system.

Now, the board won't boot. The power led stays red. No output. No nothing.
Be it with the freedombox sd or the armbian sd I had just burnt with the hope to install to emmc.

I don't have an UART, powermeter : I'm not an engineer, just an end-user with limited skills regarding linux.

Thanks for you kind pity (and answers/explanations too!)

[JohnS]

The actual boot rom (BROM) is internal to the CPU and cannot be overwritten so unless damaged your board can still boot.  Details on linux-sunxi.org

You "just" have to figure what's wrong!

John

[mascaret]

OK.
A bit obvious.

This device has its way to "autobrick"?
That's what i'd call a piece of crap.
80€ to the bin.

Anyway, thanks for the chore of an answer!

[JohnS]

What???

Did you read too quickly???

The opposite: you cannot brick it (short of doing electrical damage).

John

[mascaret]

John,

I agree with you.
I can't possibly imagine an electrical damage.
The Ethernet port seems to work (orange/green flashes). After a certain time, the board rises a few degrees in temp.
But that's all.
Having no mean to communicate with the board and at a TOTAL LOSS to explain how it has come to that state, being reminded it's brand new. Worked a week with debian+freedombox and had been used just as a proxy (waiting for a final setup which obviously will never occur).
I've had khadas and odroid boards for some time : never been in such situation. Working like charm.
And I understand from your statement that (and I'm not surprised) you have no hint on whatever the cause.
A smell of brick..?

[martinayotte]

Since you seems to have other SBC boards, it will always be good to have some USB-Serial-TTL around in your toolbox, they are so cheap, you can get some for around $1 ...
But since you don't, you can at least use one of those other SBC boards as a bridge, connecting one of its serial port available on headers to your Olimex one, and try to figure out where is the issue about booting ...
Corrupted SD card ? etc ...

[mascaret]

Thanks for your interest regarding this thread.
Alas, my job is far from computer sciences and I have not that spare time to spend (an investment for a real techie - a waste of time for me).
If there is no precise cause to investigate, the brick will embrace the bin and I will build on another device.
Thought Olimex would be the best start for a freedombox; turns out I found a slavebrick!..

[martinayotte]

(an investment for a real techie - a waste of time for me).

If you don't invest some time to figure out what went wrong, chances are high that you repeat the same mistake and end up having two board in the bin ...
BTW, maybe board is Ok, and you only having SDCard or eMMC corrupted ...

[JohnS]

If there is no precise cause to investigate, the brick will embrace the bin

Unless you damaged it, it's not a brick.

Chances are you have a power supply issue or bad SD card or ... well, some simple such thing.

John

[LubOlimex]

Hello,

Disconnecting the power supply can corrupt the software that was written to the NAND memory. If your image boots from the NAND memory, do not disconnect all power supply suddenly, also consider using Li-Po battery all the time (this prevents sudden shutdown).

If the software that was installed in the NAND memory got corrupted, then you can restore it. You mentioned that you tried several images but did you try the official one suggested by Olimex? I'm not sure if you mentioned the exact board that you have but there are links to images at the wiki article of the specific board. If you have A20-OLinuXino-MICRO with 4GB NAND then use this SD card image: https://www.olimex.com/wiki/images/f/fc/A20_OLinuxino_Micro_debian_Jessie_34_103_2G_NAND_release_15.torrent - Important! - Notice that you board has 4GB eMMC instead of 4GB NAND then you need to use a different image.

Consider that the SD card might be faulty. Also make sure to use external power supply applied to the power jack and in the voltage rage suggested.

Best regards,
Lub/OLIMEX

[mascaret]

Hi there and thanks for your interest!

It's the emmc version. Which I had no time to populate.
Olimex worked a single week (booted ok- freedombox working oob).
As I said, I unplugged it wildly (wanted to flash another sys in order to populate emmc and discard sd : so I didn't mind about corrupt fs at the time).

I burnt an olimex image to sd card (A20 lime 2 4g emmc is my model).
3rd image I tried to boot.
Power comes from the default supply bought with the SBC. Which is brand new.
Still the same. Absolutely no output. Red led on.

I can't fathom anything but a hardware failure. Quiet a short life..

[JohnS]

Commonly it's the SD card so you in effect have a bad image and so it won't boot.

John

[LubOlimex]

Disconnecting the power supply from the power jack should not damage the hardware. This is the only way we remove the power supply during our tests here. Never seen this damage a board in thousands of tries.

Something else happened. For example, removing the power supply from the jack is safe but removing the SD card while the board is powered is not safe for the card.

Solid red is a good indicator that the power supply is probably alright. The lack of green led light usually means problems in booting the operating system. This might come from a bad SD card, or bad card preparation. Did you try to another card and did you try to prepare the card with Etcher software?

Furthermore it would be a good idea to check if there is some boot output information available over the UART pins (if you have serial-USB cable)? Post the boot log.