I'm experiencing some weird bugs for some time now. I got Ubuntu 18.04.03 running on my Thinkpad T480s.

It all started with a total freeze. I think this came from a grub update or security update before.

Since then I sometimes have trouble booting my system, especially when switching from connected AC-cable to not-connected (or vice versa) or when rewaking from standby or hibernation.

The system then does not boot at all, not even the grub menu shows, just black.

This does not change even if I try to reboot about 100 times. This drains the battery of course, and sometimes I'm lucky and then ubuntu boots!

I then try to run ubuntu from live USB and to use timeshift to reinstate the system as in before those updates - but, the computer does not even detect the SSD (with the saved timeshift images on it), so that does not work.

I suspected the bug in nvme APST to cause these problems. After researching this, I edited in /etc/default/grub the nvme.core to a value of default_ps_max_latency_us=5500.

Setting this and if booting works by chance, then this message appears before booting with could not install PCI config handler for root bridge pci0 among the text.

I checked out the question My computer boots to a black screen, what options do I have to fix it? , but none of it seems to fit.

Now it happened again, I cannot boot up my laptop and I'm stuck! I don't know what to do anymore!

I would be so grateful for any help out there!

  • What video chip are you using? Have you updated UEFI and SSD firmware? – oldfred Jan 29 '20 at 15:05
  • Ive got an Nvidia MX150 chip (which I deactivate most of the times due to battery) and of course Intels graphics (i7 8550U). Actually I never dealt with UEFI firmware updates, so I guess I have not updated anything of the kind. Same for SSD firmware updates. The only updates I always did were the ones from apt upgrade, so mostly packages, kernel upgrades and other software. – MJimitater Jan 29 '20 at 15:12
  • @oldfred do you recon I should consider UEFI and SSD firmware updates? – MJimitater Jan 29 '20 at 15:17
  • Whether using Linux or not almost all systems need UEFI updates, anyway, for mitigation of Meltdown and Spectre CPU vulnerabilities from cpu speculative execution and caching. Both Linux & Windows have updated operating systems and newer version of virus get released. Some newer systems will update from Linux. fwupd.org/lvfs/devicelist & fwupd.org/vendorlist My Samsung SSD has a bootable ISO as an option for update. – oldfred Jan 29 '20 at 16:51

Thank you @oldfred for your help!

So I proceeded with several things:

  1. In /etc/default/grub I changed the nvme.core to a value of default_ps_max_latency_us=0, so I switched off APST.

  2. In /etc/default/grub I added nomodeset, according to How do I set 'nomodeset' after I've already installed Ubuntu?

  3. I followed the instructions on https://itsfoss.com/update-firmware-ubuntu/ , using the tool fwupd to update my firmware.

The booting works! At least this one time now.

Anyone feel free to edit/post answer with technical insight, because in the end I still don't know what exactly was the problem. I just hope it works now :) I'll edit this post if anything happens.


Today the same problems occured again; I cannot boot into ubuntu, it seems like almost the disk cannot be read. I will try to check the disk sanity. Also, this message appeared cannot start pxe over ipv4.

1 in 30 reboots might work, the other 29 fail. And in this one time the system normally crashes/freezes after some time.

EDIT 2: I contacted Lenovo, it seems like my SSD is broken, they are sending me a new SSD.

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