beolover: Beogram 400x DIY Keypad Restoration Kit ... "How-To"

This post discusses a new keypad restoration kit that is now available through DKaudiolover, made by a partner company TangentialLab. The kit is available through the DKaudiolover store and is also used when ordering the DKaudiolover Keypad Restoration Service.

I have restored several dozen keypads over the past few years and have learned a lot in the process. Extracting the original keypad plate (without bending it) and then coating it reliably, without showing signs or wear (in the spots where the original lacquer wore through) and then it not immediately wearing out again is not really possible/reliable/repeatable (I tried!). Getting everything back to the level of quality it was originally can't really be done at the scale of "one keypad" at a time.

I have felt increasingly that given the right set of tools, and the secrets of the procedure, this could be something other restorers and enthusiasts may be able to do. The kit was put together using this experience and includes most of the items that would be difficult to source otherwise.

Note: If you're doing this yourself, make sure you read this entire post (and the user guide) so you are very familiar with the process before you begin. Some steps involve timing and it's best to know what's coming up.

Today, I have 4 keypads that I'm working on, and I'm going to use the restoration kit for each of them.

This first step is relevant to DC model keypads only. DC (551x/552x) keypads that have "START/STOP" buttons and very sticky glue. AC (550x) keypads have "ON/OFF" buttons and generally don't need to go in the oven. The oven is required to loosen up the sticky glue B&O used on the later models. For earlier keypads, you can usually just press on the back of the keypad and it'll easily pop off the frame, as will the plastic pieces. If your AC keypad does not easily pop off, you can still use the oven method, it works for any keypad, even if it has been previously restored.

According to the guide, the first step is to place the DC keypad inside an oven-safe aluminum container to protect it from heat-cycling during the oven stage.

Place this container inside a preheated oven at 300ºF/150ºC for about 20 minutes. After this time has passed, use heat-resistant gloves to remove it from the oven. Starting on the back side, use a large flathead screwdriver, placed between two key back pieces and rotated (to apply sideways pressure on both keys); they should break loose. Continue this process until all the backs have been removed, then put the screwdriver underneath the center piece and pry it upwards.

If you have done this quickly, there is a chance that the front side is still hot, if not then you should pop it back (in the container) in the oven for another 5-10 minutes. You don't need to keep the original plastic pieces, we will not be re-using them.

Next use the included x-acto to slide under one of the corners of the keypad plate, then slide across to the other side (front to back or vice-versa, not side-to-side yet). This will give you a gap big enough to fit a metal spatula, I suggest using a paint/spackle spatula.

Slide the spatula towards the center, make sure not to slip as you can easily scratch the frame. When you get to the inside edge of the "45" or "33" keys, you'll have to start rotating the spatula towards the front (so it's pointing towards the back). The center section is the most difficult to get across, so it's best to approach from both the left and right sides before attempting to go across. Trips back to the oven can help keep it warm if you are having trouble. Do not put too much pressure as it could suddenly break free and scratch things up. Near the end of this process, ideally you will be in this position:

Try to slowly lift "up" instead of pushing back, as it could break free and it's best to break upwards and not towards the back.

Next, for both AC and DC models, we need to deal with the old glue that is stuck to the frame. Use the included x-acto to "slide" under the glue as much as possible, try to avoid scratching the metal surface. There is a perfect angle you may find where it easily slides under. You can also "bear down" on the circle in the middle of the blade, this is the best place to put pressure.

Make sure there is no glue left over on the black painted areas, it's better to scratch the paint than to leave the glue.

It's the same process on the back side; you may even decide to start on the back side, since it's a little easier and you can practice getting the right angle and pressure.

Rinse it with warm soap and water, remove all loose glue. Use a melamine pad ("Magic Eraser") to clean the surfaces (don't put too much pressure on the visible areas of the frame as melamine can scratch or remove the lettering). Make sure it's dry before continuing.

Next, use the included paint pen to touch-up the black lines along the edge of the frame. They will have finger marks and potentially a few scratches from removing the glue.

Next, find the small bag with 4 white plastic pieces. These are alignment pieces used to make sure the keypad is centered front-to-back on the frame. They have a special type of adhesive that is "reposition able" and will not damage the frame. Remove the backings and place them at the 4 corners of the frame:

Before proceeding, test out the new keypad plate between these 4 pieces, make sure it fits and get used to centering it horizontally "by feel". I.e. you will feel when the keypad plate and frame are lined up on the sides.

Next, we'll need to remove the backing from the new keypad. It can be a little difficult to lift the corners of the backing, if you have trouble then just put a light diagonal "nick" in the corner and lift one of the side of the nick; it's the best way to remove the backing from this very strong adhesive, I don't usually attempt to get the corner lifted any other way.

The next part is critical. Don't touch the back of the plate in areas where the adhesive is now exposed. Hold the plate by the left and right edges so you can "feel" the horizontal center point with the frame. Don't push down on the keypad until you are satisfied with the centering. You can "nudge" it about 0.2mm side to side when it's lightly resting on the frame.

Note: I don't recommend re-lifting the plate to reposition it; once it's got a strong bond, it won't let go easily. If it's in a really bad spot and you can't nudge it, then just contact us so we can help.

Once you have it in a good place, press down in all the areas where the plate touches the frame.

Next, we will be preparing the black plastic pieces for adhesive. Keep the pieces "all together", do not cut them apart yet. Wipe down all the pieces to remove excess dye (there could be a lot!) and oils from the surfaces where we will be applying adhesive. Don't waste the wipe on areas that won't have adhesive, focus only on the front side.

Once the pieces are clean, wear gloves and be in a well-ventilated area. Wipe all the cleaned front sides (in the areas that will have adhesive) using the adhesive promoter. Remove gloves and wait for the promoter to dry.

Start applying the adhesive to each piece, making sure it is centered (the small pieces of adhesive are slightly larger than the key backs). Press down on the entire surface of each piece, and the edges of the small pieces (so the bond is edge-to-edge). Try to avoid air bubbles; if you get one, you can try to put a hole or two in it using a blade and carefully push the air out as much as possible.

Bend the pieces back and forth a few times to weaken the connections and cut them off (using a blade or wire cutters). Trim the sprue's so the edges are completely flat in the previous connection areas.

Note: The two upper back pieces, used for 33/45 keys, ARE DIFFERENT from the other key backs. Make sure not to mix them up! They are dimensionally unique, optimized for a tiny slope the keypad has.

Next, put a nick in the corner of each piece and peel the backing off. Below you can see where I nicked the center piece before peeling it off:

Last step is placing all the pieces into the keypad frame. Start with the center piece. Next, align each key back piece with the center of the key, about 1mm away from the center piece. You can drop the key backs in lightly and then position them with the chisel blade before pressing down too hard.