Manjaro doesn’t boot/blackscreens

[Takakage]

@entropy_dev

sadly i am not able to manjaro-chroot

Unmounted:
  ID-1: /dev/nvme0n1p1 maj-min: 259:5 size: 300 MiB fs: vfat label: N/A
    uuid: B2AF-2FA2
  ID-2: /dev/nvme0n1p2 maj-min: 259:6 size: 1.82 TiB fs: btrfs label: N/A
    uuid: 8b8ca515-8b79-42b4-bac3-251d6304ee22
  ID-3: /dev/nvme1n1p1 maj-min: 259:1 size: 300 MiB fs: vfat label: N/A
    uuid: EB04-A5BC
  ID-4: /dev/nvme1n1p2 maj-min: 259:2 size: 922.42 GiB fs: btrfs label: N/A
    uuid: e12ec2ec-7d83-406e-9f44-a6c450f272d6

It appears that your installation used btrfs. You may want to check

[HowTo] Recovering from an interrupted update/upgrade

Difficulty: ★★☆☆☆ So you couldn’t wait until the update process had completed and you went for the reset/power button, didn’t you? And now you’re getting the message that you don’t have a kernel installed. Well, you’re not the only one — we’re seeing it happen all the time. So, here’s how to fix it, you impatient n00b. If you don’t happen to have a recent Manjaro installer USB/DVD/CD handy, direct your browser to this wonderful page, download t…

Aragorn provides nice instructions on how to manually chroot when using btrfs.