Open and unbrick an MR8300 - UART serial

Hello, just a little note.
I've got some MR8300. I've bricked one of this with a wrong command (don't do a fw_setenv kernsize=500000 !!! Don't use = or the next start won't boot!)

Opening an MR8300: 4 screws in the bottom (under the rubbers) then open gently the cover on the top.

PINOUT of UART is: [VCC] [ ] [TX] [RX] [ ] [GND]
The VCC is optional.

Can you please add this information to the MR8300 devicepage?

In case you do not yet have a wiki account: Applying for OpenWrt wiki account

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What the log output from uart do you have, I would like to see what is the output when the MR8300 switch to 02 partition after sysupgrade, what is the error reported


sorry, i don't have any log. I remember something like this:

NAND read: device 0 offset 0x5f80000, size 0xa080000
Attempt to read outside the flash area
0 bytes read: ERROR

I've made a typo. The pinout is:

:wink: I guessed so.
I had to check myself and found TX/RX/gap/GND according to your scheme. I left VCC.
Thank you.

I have photos for PCB, opening case and UART pins, but I haven't the right to add them to the TOH.
May I send them to you? I have already updated the text infos for the matter.


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Done. Thank you.

well done the new wiki page, badulesia! thanks

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