brick after firmware update on emms

[sashka_amur]

not so long ago I got my pbpro.
with installed manjaro 20.03 kde.
I created a bootable USB stick with debian. and downloaded the latest image of Manjaro  XFCE 20.08.
Before flashing, I checked with the LSBLK command that emms is in mmcblk2. and copied DD.
after that everything worked.
Today I decided to return to where. Only now LSBLK returned me that emms is on mmcblk1. ok uploaded there.
after the end of the process, turned off the laptop. but it's frozen. 
I waited for a while and turned it off by holding the power button for 15 seconds.

after which the laptop will not turn on. the power-on indicator is neither red nor green. the screen does not show anything either.
only the cpu temperature is an indirect sign of operation. after a short press on the power supply after a short time, it becomes warm. after 15 pressing the power button it cools down quickly.

what will be the assumptions about what happened and what to do about it?

[xmixahlx]

i would guess you borked uboot somewhere, unfortunately.

write a new image to sdcard and boot. you may need to disable emmc.

[wdt]

Some of those older manjaro distros had a problem with extlinux.conf,,
path needed to be adjusted, 3 places, make it ../dtbs/rock---,,, ../initramfs-li-----,,,, ../Image
IOW, the "../"
If you can mount on another computer and check.... but I see on emmc, a bit harder
Your post is a bit unclear....

[xmixahlx]

if they reinstalled to emmc that wouldnt matter.

[sashka_amur]

i would guess you borked uboot somewhere, unfortunately.

write a new image to sdcard and boot. you may need to disable emmc.

the instruction from this topic helped.

a metal clip always works, buttons not always.

manjaro kde plasma 19.12 starts with emms