Case of the Blue Screening Computer

This was a fun one to troubleshoot.  I deployed a brand new Dell Optiplex 390 to a guy in our electrical engineering lab with a fresh copy of Windows XP.  A few weeks go by and he puts a ticket into our Help Desk about his PC bluescreening in the driver for this USB to Serial device. Thinking it could be the USB to Serial device, I got one that was “shrink wrapped” and headed over there along with an updated driver from the web site.  Same issue.  I also noticed in the event log random BSODs happening in the video driver and other random OS files unrelated to the USB to Serial device. We tried the USB to Serial on a laptop with the same device he was testing with (some type of electronic gizmo): worked fine!  I brought back another Dell Optiplex 390 and I switched the hard drive out.  Within 10 minutes, we were getting the same BSOD in the same USB to Serial driver.

I took another brand new Dell Optiplex 390, put Windows XP on it and took it back.  Can you guess what happened?  Yup: an hour later, another BSOD.  I took a power strip back there and plugged his PC into a different electrical outlet.  Since then: no BSODs!

I took the two “bad PCs” back to my bench and both pass the Dell hardware diagnostics with flying colors.  We never had a PC in this spot and no doubt that this electronic gizmo he’s testing with must be causing some electrical interference or “dirty power” issue.  I’m not sure why this issue didn’t show up on the laptop, however.

Update (2/7/14): Upon further reflection, this problem appears to really be the Tripplite 19-HS USB to serial adapter itself and not the PC since I was getting this on yet another 390 with this adapter.

– Soli Deo Gloria