# Repairing a Pioneer head unit



## ceri23 (Aug 10, 2012)

Need a little help. I don't do this on a regular basis so I'm looking to the experienced repairmen out there. I solder bypassed the picofuse in my 880PRS to get rid of the alternator whine being picked up by the preamp. That all went fine (at least I hope).

While I was in there, I tore the wire running from the faceplate to the PCB. I ordered a new one and it arrived today. Before I knew what went where exactly, I took apart the actual CD drive cage (8 springs keep it floating in the middle to avoid skipping). The springs were a pain, but I got them back together. 

This brings me to my question. When I reinstalled it and drove around, I was hearing a constant light tapping sound. This would be noticeable to non-audio people. I opened it back up, and I believe the sound is coming from the CD ROM's "upper arm". I've got an extra spring left over. It's about 1 cm diameter with only about 3-4 winds in the coil (short and wide by comparison to others found in the unit). I'm guessing this is supposed to keep the upper arm from tapping, but I can't find where to install it. Does anyone have any internal pics of a CD unit from the inside of a Pioneer (or specifically an 880PRS as I know they are commonly opened up). I've got some kind of number on the unit listed as 55K1NH5753FF7. I'm guessing this is a unique serial number as google doesn't bring up anything. I'm trying to avoid fully dismantling the CD ROM unit as the little springs are quite difficult to get back into place. 

I know this might be a long shot, but any help would be appreciated. The tapping wont do.


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## ceri23 (Aug 10, 2012)

Just wanted to say I got the spring reinstalled. It wasn't an easy one to find (or get put in place), but when it finally did get where it was going, it snapped in with a satisfying thunk. 

I also wanted to say that I feel like I've really gotten to know this head unit over the past couple of days. I learned to solder on what is quite possibly the most difficult piece of soldering imaginable. 17 pins/leads less than a millimeter apart. 


























That's the old one which was obviously done by a machine. What might not be easy to see is that in the first picture, with the ruler in it, each of those 8 pins has a lead from the other side running between them. I didn't realize that at first (being dumb), so I had to go back and heat up the fresh solder and scrape away the stuff that had overlapped those. All this with a $13 battery powered soldering iron from Walmart. I'm quite pleased with myself. I haven't experienced the joy I received when I turned on the truck and saw the screen light up in a long time. 

Don't rip the wire ribbon running from the faceplate mount to the PCB. Just don't do it. I don't know why Pioneer didn't sell the two pieces already machine soldered together. I also don't know why the new 80prs doesn't include the IPBus like the 880. I'd have bought one, but no HD radio and no expansion capability meant I had to keep the 880 working. Soldering the picofuse was going to be my challenge of the week. Reassembling every screw, spring, and several solder points in this box was well beyond what I thought I could pull off. 

No more alternator whine, and a shiny new customized Zed Leviathan III in the mail to plug this 880 into.


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