I am having real trouble booting to my Thinkpad X230. This is a recent development and I have no idea how to debug it. Can someone recognise the symptoms and help me debug it please?
I have had the Thinkpad dual-booting Win7 & Ubuntu for a few years (since 14.04) without any issues whatsoever. Recently, I've decided to upgrade from 16.04 to 18.04.1. A fresh install later and all was well.
I don't use the Win7 partition very often but I had to log in soon after the upgrade to 18.04.1. Once on Windows, I accepted the BIOs critical upgrade suggested by the Lenovo software manager: upgrading from 2.70 to 2.73.
Since then Ubuntu stopped booting other than in rescue mode. This is supper annoying because I loose control over the brightness of the display, which is set to its minimum, and I can barely see what I am doing.
I have tried the following (unsuccessfully)
Downgrade back to BIOS 2.70 (it seems that not all components of the upgrade have actually been downgraded)
Installed Kubuntu 18.04, Ubuntu Mate 18.10 (the current version on the laptop)
Any help is greatly appreciated