Saturday, July 05, 2008

How to service the buttons and LCD on a Porsche Becker CDR-220 radio

The CD player on my Becker CDR-220 quit working, so I picked a used one up for $100. The used one worked great, but the detachable face had a couple wonkey buttons. The face on my broken unit worked perfectly, but the lamination was coming off on the buttons. I decided to take the two faces apart and put the pretty buttons into the good detachable face.

The process is pretty simple. All you need are a couple tiny flathead screwdrivers for prying the various clips apart. While exploring the process I went past the point of just removing the buttons and also disassembled the LCD, so if part of your LCD screen isn't lighting up, you may be able to clean the zebra connector and put it back together, saving yourself the cost of a new face.

Begin by lightly prying the two side clips apart.

radiofacesideclips

With this entire process, be sure and use some finesse. Nothing should take too much pressure. Pry one side, then the other.

Once the sides are loose, gently pry open the three tabbed clips along the top of the radio face. This is best achieved by sliding the screwdriver in between the face and the backing. I tried depressing the tab with a screwdriver and pushing it from the back, but that resulted in broken clips. If you pry the crack between the face and back, the clips just pop open.

radiofacetopclips

Once you have the side and top clips open, the two halves of the faceplate simply unhinge from the bottom. When you seperate them you'll see the back of the circuit board mounted to the front of the assembly. To remove this, just gently pry around the edges everywhere you see a black dot. The black dots are the posts upon which the board is mounted.

radiofaceboardback

Don't unhook the metal retaining brackets unless you need to remove the LCD or service something on the front of the board. If you remove them, when you reassemble the unit, you'll need to rehook the bottom clips first very, very tightly, then push the top of the retaining bracket up and bend the top clips (one of which is indicated by the arrow) down. The pressure needs to be on the bottom side of the metal LCD retaining bracket to ensure that the zebra connector has good contact. Otherwise when you reassemble the face, there's a good chance that only random portions of your LCD will light up.

Now that you have the circuit board removed from the face plate, you can access all the buttons. They're simply held in place by plastic brackets with rubber strips that allow the buttons to travel up and down to contact the board.

radiolcdremoved

Gently pry out the retainers, and the buttons will slide right out for replacement. The plastic brackets on the backs of the buttons only allow them to go in one direction, so you don't need to worry about getting a put in upside down, but it is good to remember which button goes in which slot.

If you need to service or replace the LCD or the backlighting LEDs, here's a photo of what the board looks like with the LCD removed.

radiocircuitboard

While I had the units open, I cleaned all the connection points with contact cleaner. Like I mentioned before, when replacing the LCD, make sure you connect the bottom of the retaining cage first with it pushed in all the way. Then push the top side up and fold down the remaining three tabs.

It all just snaps back together. Be gentle and make sure everything is seated correctly.

In the face I took apart with the wonky buttons, I found that the rubber behind the buttons had just gotten pulled off center a bit. When I put it back together, I made sure everything was nice and in place, now it works perfectly as well -- although it has all the ugly delaminated buttons in it.

Now I'm trying to decide if I'm going to pull apart the Becker unit with the broken CD player and see if I can't fix that. If I do, I'll post photos.
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