It would really help if you told us what OS you are using. Type "uname -a " at the prompt. And copy here.
If dmesg is somehow screwed up with a bunch of error messages. You can look at a file, if it is there /var/adm/messages. However, this file is not always there. You may have to setup dmesg to write out to this file. Do a man on Dmesg.
Also, If you have some kind of command that allows you to see your Hardware, use that.
Or if you have access to logfiles, it will be there whenever you reboot the system it is captured there.
On HPUX it is under /var/adm/syslog/syslog.log. Your location and mileage will vary.