When I took my DS Mk1 out of standby this morning, I saw a screen that I never saw before, didn’t know existed.
“Test Data”. Two tests are offered.
A voice in my head said don’t do it. Then the word “brick” came to mind. So of course I touched the Test button. Yeesh, it turned red. Then it read “passed”.
What did it test?
Hmm. In all the time I owned the MkI I don’t recall ever seeing that. 
Might be worth touching base with PSA to find out.
It came and went harmlessly. I’m just curious.
If our buddy Ted were still here you’d have had the answer in no time. 
I miss Ted.
Your cognitive state?
New Jersey.