Pioneer DEH-P840MP Troubles

[caddy39 10+ year member]

Hi everyone, I have a Pioneer DEH-P840MP deck and I love it. However, the other day I was driving and it just shut off. I turned the car off, turned the car back on and away it went. No big deal. Sure enough, it happened again about a week later. Only this time turning the car on and off didnt work. For the next couple weeks the deck basically had a life of its own and chose whether to turn on or off. Even if the deck didnt turn on thou, after power was taken away, the face would still slide out so I could detach it. Now, Nothing. It baisically seems like there is no power. So, figureing that a wire was loose in the back somewhere, I took the deck out and checked things out. I took a testlight and found power at the 12V Constant but things were different when I checked the Accessory. there is a small resistor on the accesory wire and before the resistor there is power, but after, the test light doesnt light up. I figure that the resistor is blown somehow? The thing I am curious about is that the resistor is very small (not sure how many ohms) and I wonder if the resistor is working but the test light just cant pick up the voltage? Any suggestions? Anything else for me to try? I have pressed the reset button numerous times, there are not blown fuses that I know about (I checked every one) Any help at all would be awesome because right now I miss my tunes. Thanks a lot.

Michael B

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[c0la 10+ year member]

When it comes to the 8400 or 840 there is a fault in the faceplate cover(little black thing that goes around the cd player face. It doesnt have a notch for the first face to slide out and rubs the wiring. Might want to pull yours off the unit and check to see if the notch is or isnt there. This is sometimes the problem with these particular units.

hope it helps

 

[caddy39 10+ year member]

When it comes to the 8400 or 840 there is a fault in the faceplate cover(little black thing that goes around the cd player face. It doesnt have a notch for the first face to slide out and rubs the wiring. Might want to pull yours off the unit and check to see if the notch is or isnt there. This is sometimes the problem with these particular units.
hope it helps

You mean the black thing that is left when you take off the front face? I think I understand what your talking about.. Thanks.. I'll check it out.