Jensen stereo not storing settings

[PaulAm]

I got skunked with this unit (seller kept dribbling out little bits until the feedback window expired and I was too far into it to just cancel the entire thing).  It's a Jensen VX7528 radio/nav/cd/dvd/bluetooth etc unit.  It seems to operate fine except that it is not saving various option settings (equalizer settings, turning beep on/off, turning cameras on/off, etc) although it does save the station presets.  This is highly annoying since the defaults are not very good.

Jensen customer service is not helpful.  They said 1) try the reset and 2) if that doesn't work replace the radio.

On top of everything else,  Jensen discontinued this model.

I'm probably going to open this up and see if I can see anything.  Anyone have any experience with this kind of problem?  Any clues as to what I should look for?