On Mon, 30 Sep 2024, Pavel Machek wrote: > > > No beep. And no beep when I tried booting with RAM removed. > > > > According to: > > <https://download.lenovo.com/ibmdl/pub/pc/pccbbs/mobiles_pdf/x220_x220i_x220tablet_x220itablet_ug_en.pdf> > > pulsating power-on LED indicates the sleep mode: > > > > "The power switch stays lit whenever the computer is on, blinks when the > > computer is in sleep (standby) mode, and is off when the computer is > > off." > > So... I disconnected CMOS battery and now I have two different > blinking patterns. I googled a bit, and it seems it is symptom of some > PROM failing. So likely Linux had nothing to do with this, and sorry > for the noise. One final thought: have you tried another PSU? I've seen all kinds of weird behaviour with hardware due to issues with a PSU. To give you an odd example: an Ethernet switch failing to communicate despite the link established with exactly one other device and working correctly with everything else. What would you blame? The other device? No. With its PSU replaced the switch started to communicate with said device too. If there are power regulators onboard the x220, it might be worth checking them too (as well as any associated electrolytic capacitors). > I have X230 now. Suspend/resume works without bricking it with > (different?) 6.12-rc0. I hate the keyboard, and X230 came with bad > battery and won't charge X220's battery (bad Lenovo!!), so I got > another X220. If this one dies with blinking LED, I'll certainly let > the world know. Good luck! Maciej