Additional test and information: Kernel panic happens in both cases: - when only using battery - when attaching power cord prior (and during) wake up from suspending to disk. If just before supending to disk I press Ctrl+Alt+F10, after wake up I can see the same messages that I saw just before computer sleeps. Also, for just 2-3 seconds keyboard respond (if I press Enter, new line inserted, logs goes up in screen), also Caps lock works for just several seconds. But after these few seconds, Caps lock stars flashing.