There is no entry for chkdsk /f looking as described in post 6. There is an entry for the chkskWelcome
First check that reporting is turned on
Disable Windows Error Reporting Logging — MAXIMUMpcguides – Windows 7 tips, tricks, help, and how-to guides
Disable logging should be off. Disregard the instructions given in the above link that shows how to disable.
Read post number 6 to be sure you looked for the log the right way
http://www.vistax64.com/general-discussion/266686-chkdsk-log-location.html
it is onMaybe this tutorial will give you a lead. Can you turn on the reporting?
Check Disk (chkdsk) - Read Event Viewer Log - Windows 7 Forums