I decide to contact Dell. It's a Sunday, so I choose email support. Here's the automated response after filling in the web form:
Thank you for choosing to Communicate Online with Dell Computer
Your request has been sent to a Dell Technical Support Representative. Please note that all correspondence is tracked by the e-mail address you provided in this form.
Please reference [my-own-snipped-email] when referring to this electronic request. If you change your e-mail address you may be required to provide any other addresses you may have used in previous correspondence.
Case number: [snipped]
If you are getting an error, Please include the exact text of the message.
No error displayed
Description of problem
Studio 1735 keyboard began to stop working. At first it was just omitting the odd key, then it stopped registering any keystrokes whatsoever. Rebooting didn't help. Problem evident across all software applications. Also, fan seems to have begun running on highest setting non-stop.
Description of any troubleshooting steps you have taken
I tried rebooting laptop. I also made sure the problem was evidenced in several different software programs. No new software was recently applied since this problem started showing up.