Black screen leaves no errors or .dmp??? what to do

[zapp22]

guys I have a machine I maintain for someone else that has twice reportedly thrown a black screen but not a total bail - in other words display goes black, something is still running, later after long wait in one case Windows reported on screen a recovery of some sort and after that worked ok. second time on opening IE10, same blackness, later recovered. Error log has lots of entries but no telltale Errors.
one lone error had "crash dump failed to initialize" but I could not tie it to either crash.
ran drive diags and it passed.
ran memory diags and passed.
checked physical things - connectors, cables, devices.

this is win7 home x64 on late model hp pavilion with no history of issues.

I'm baffled. any help would be appreciated

 

[Roderunner]

Hi zapp22,

Once you've done this, post your findings as stated by Seven Forums. View attachment 282512

 

[zapp22]

haven't had a bsod.