2nd to 3rd doesn't grab

Shifts nice from 1st to 2nd but fails to shift from 2nd to 3rd tranny doesn't grab " this is a 97 z71" could it be the 2nd to 3rd solenoid because it just went all of the sudden. It didn't gradually go it just went.
2nd to 3rd doesn't grab

If I am not mistaken this automatic trans is controlled by Mr. Computer. Mine had trouble making its mind up when changing gears and it wsn't to long after that it went poof :dead: .
The trans burnt up because the computer quit putering. Had to replace both.
Think I would bring it to a transmission shop or a dealer