General method to determine if latop hardware for 'recognizing external montor' is ok

Problem: Unrecognized Exteal Monitor

I have a laptop (thinkpad w530 ruing ubuntu 14.04) which does not recognize an exteal monitor--neither via VGA, displayport, whatever.

A few years ago I ran windows on this laptop; back then the same laptop succesfully coected to an exteal monitor.

Since then, I've switched to linux, dropped it a few times, got it serviced, etc. Software's changed and perhaps hardware got damaged.

I'm not sure if I have a hardware problem or a software problems.

Question: Live CD?

• does a live CD exist (windows or linux or bsd or whatever) that I can boot and use an exteal monitor?

• in linux, should dmesg or anything show when a monitor has been plugged in (whether on vga or displayport)?

• any suggestions for identifying the problem?

thanks