Review this article for details but if your transmission fuse blew, the transmission would be in limp mode which means you'd have only third and reverse when shifter is in D, D3 or 2nd gear and reverse if your shifter is in D2 (third gear achievable via manual upshift to D3 or D).Particularly the 2-3 shift is off a trans fuse I didn’t know that ?
A bad 2-3 solenoid (stuck on) would translate into a no 2-3 upshift as well as no fourth gear either...Verify exactly what gears he has and what gears are 'missing'.