Pro Bricked! Solutions?

[mspohr]

I have an early production model PineBook Pro. I have always had problems installing software (mostly won't boot stuff).
I finally got Armbian to work well and used it for awhile. However, one time I did an upgrade it failed to boot (I get Armbian logo and a spinning circle.
I gave up on it and put it on the shelf a year or so ago. Just brought it out again to see if I could revive it or trash it.
I haven't been able to get it to boot from the SD card (this has been a constant problem from the start... I believe it's a problem with early production). I've tried all manner of things but I can't boot anything. Looks like there is a new bootloader Tow but people seem to be having problems with that also.
I was wondering of it would be useful to try to replace the motherboard with a newer version (and hopefully a functional bootloader)?

[wdt]

Well, when you said you installed armbian, you said booted from SD (Nov 20/2020)
So, you have 2 problems
And I guess you don't know that there is not a bios on ARM cpus (or rom on mb)
There are 4 steps in a boot
ROM in cpu, with VERY little memory, searchs for idbloader (fixed search order, specific locations)
idbloader enumerates and activates memory, so now enough memory for
uboot, which with an ALTERED search order looks for config files,
the first config found tells where kernel, initrd and dtb is located and loads them
1) your new uboot from armbian seems to fail loading from SD, if SD is correct for booting
2) because you see armbian logo, uboot is done, new kernel, initrd or dtb is faulty
disable or remove emmc, see if you can get a SD boot, if yes,,
re-enable emmc 2 seconds into reboot, check with lsblk to see if you got timing right
edit boot.txt and recompile or alter links in /boot to boot previous kernel, initrd, dtb (all this on emmc)
------------
every image I have seen (except for 1) will have a idbloader and uboot and maybe trust in 1st 16M(32768 sectors)
so the armbian image that you installed a year ago had these files,,,,
they are NOT in a filesystem, it is a raw read,,, that is why the 1st partition starts at 32768 or 62500(manjaro),,,
room for the boot files

[_radv_]

I have an early production model PineBook Pro. I have always had problems installing software (mostly won't boot stuff).
I finally got Armbian to work well and used it for awhile. However, one time I did an upgrade it failed to boot (I get Armbian logo and a spinning circle.
I gave up on it and put it on the shelf a year or so ago. Just brought it out again to see if I could revive it or trash it.
I haven't been able to get it to boot from the SD card (this has been a constant problem from the start... I believe it's a problem with early production). I've tried all manner of things but I can't boot anything. Looks like there is a new bootloader Tow but people seem to be having problems with that also.
I was wondering of it would be useful to try to replace the motherboard with a newer version (and hopefully a functional bootloader)?

I get it.  
I'm having a similar problem with a Pine Phone and without solution.  My thing won't hardly read the SD card, and, separately, I mucked-up the original file system on the device. Just stating I know where you're coming from; likely more then just you & I.  I'd hate to throw out $200, but I'm not getting useable support, yet there's other things I haven't tried. I guess it's a (maybe futile) hobby for a long winter. 

@mspohr has some remarkable information. Maybe something there is useful.  Mine's got something to do with initrd (among other things I'm sure). 
Is uboot located on the MicroSD card image or the device's image? Somewhere else? There's got to be a better, more accurate, word then " image" ...data blocks . . .

[mspohr]

Well, when you said you installed armbian, you said booted from SD (Nov 20/2020)
So, you have 2 problems
And I guess you don't know that there is not a bios on ARM cpus (or rom on mb)
There are 4 steps in a boot
ROM in cpu, with VERY little memory, searchs for idbloader (fixed search order, specific locations)
idbloader enumerates and activates memory, so now enough memory for
uboot, which with an ALTERED search order looks for config files,
the first config found tells where kernel, initrd and dtb is located and loads them
1) your new uboot from armbian  seems to fail loading from SD, if SD is correct for booting
2) because you see armbian logo, uboot is done, new kernel, initrd or dtb is faulty
disable or remove emmc, see if you can get a SD boot, if yes,,
re-enable emmc 2 seconds into reboot, check with lsblk to see if you got timing right
edit boot.txt and recompile or alter links in /boot to boot previous kernel, initrd, dtb (all this on emmc)
------------
every image I have seen (except for 1) will have a idbloader and uboot and maybe trust in 1st 16M(32768 sectors)
so the armbian image that you installed a year ago had these files,,,,
they are NOT in a filesystem, it is a raw read,,, that is why the 1st partition starts at 32768 or 62500(manjaro),,,
room for the boot files

Thank you for this information. It's the best explanation of the boot process that I have read.
I'll give this a try. It looks complicated and may be beyond my skills but a good project for a snowy weekend.

[wdt]

@_radv_
Please understand,,,, pinePhone.... vrs..... pinePhonePro
the 1st has allwinner A64 cpu, the 2nd has rockchip rk3399 cpu
Compeletly different, at least vrs uboot and locations (and especially dtb,, this is essentially your bios)
Info for 1st same as original pine64 SBC,,,,
IIRR priority for A64 boot is SD card 1st
A64 is really efficient vrs power draw, but weak computationly
You could try,,, all on SD card
------
save 1st 16M, save mbr, blank (/dev/zero) 1st 16M, restore mbr
-----
Not sure 16M is right, look at card with fdisk to see where 1st partition starts,
save everything before that (so if you have made an error,, easy to go back)
there is sure to be a uboot on internal emmc
to find search order on uboot
strings uboot | grep _target ,,,,, mmc1 is SD, mmc0 is emmc