Problem with Kenwood KDC-X869 head unit

I bought the Kenwood Excelon KDC-X869 about four years ago and installed it myself. I have never had a problem with the unit until recently I turned the car on and the radio would not turn on. The head unit has one of those motorized faces. The face would open up, but the unit would not actually turn on. This obviously showed that the unit was receiving some sort of power, but wouldn't actually turn on. So, I pulled the radio out, checked my connections, which looked good. Just in case I was wrong, however, I purchased a new wiring harness, soldered all connections and tried again. I got the same problem. So, I decided to troubleshoot by disconnecting all the wires except for the constant and the switch on wires. I spliced those two wires together, ran a power wire directly from the battery, which I connected to those wires simultaneously. I then grounded the radio to the battery, and the unit lit up and worked perfectly. So, I can't figure out why it won't work otherwise. Any help at all would be appreciated. All I can think to do is wire the constant and switch on together and have the radio constantly on at all times, which is not optimal, but I can't really afford a new radio.  Oh, and if it matters, the vehicle is a 1999 Acura Integra LS.

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I be tossin and flossin, my style is awesome. Causin' more family feuds than Richard Dawson.

You're getting warmer- actually the problem is right under your nose.  I'll bet your constant wire has lost power, since (I'm assuming) the face would only open when the key was turned (which would lead me to believe you have a good switched source, but no constant).  Check your fuses, starting with the under hood location, then if necessary, check those inside as well. 

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My ex once told me I have a perfect face for radio.

I have the kdc-x859 and I got the same exact problem. I found out that the problem was the ribbon cable that connects the face plate to the main board. I guess over time, all that opening and closing causes the ribbon to tear. Anyway, I replaced the ribbon and it fixed the problem, however, I think I caused another problem. Somehow, the deck will play in the "cd eject" position. I had to twist the screw that swings the front piece open and closed when I did the repair, but now it's all out of whack. It doesn't seem to know what position to be in when it needs to be open. Maybe I messed it up when I tried forcing it open a little in the beginning....before messing with that screw. I tried pushing the reset button, but it didn't help.

Anyway, here's a link to the instructions if you're interested:

https://www.bipster.zapto.org/Fun_Stuff/How-To/KDC-MP8017/Page1.htm

It's a different deck, but pretty much the same steps.