Fixing a Standard ColecoVision Controller
Christian Oliver Windler 1997
/!\ READ THIS ENTIRE MANUAL BEFORE DOING ANYTHING /!\
First take the Controller apart. (4 Philip head screws.) The center one doesn't need to come out at this time. That just holds down the circuit board. Next spray a small amount of WD-40 under the four metal leaf contact switches. Clean up any excessive WD-40 with a napkin or paper towel. Note: WD-40 when it dries it leaves behind a residue, however that residue over time can recollect debris. After each use of WD-40 one should use 99% Isopropyl Alcohol(from a drug store) to clean up that residue. The best method and recommend by Yurkie is to use only a de-oxidizing agent, such as DeoxIT if available. This is an electric contact cleaner.
See if the Controllers Directional work, push them repeatedly to get the WD-40 into the contact locations. If Controllers Directional are not responding recheck the contacts for dirt/corrosion, by sliding a piece of a card stock soaked with WD-40 or DeoxIT back and forth under the metal leaf contact while pressing down on the leaf contact. If using WD-40 don't forget to clean up the residue with 99% Isopropyl Alcohol. Recheck to see if the direction works, if not read on...
Check the metal leaf contacts for cracks and breakage, by pressing down on it in random locations with a pencil tip. If you find some cracks then you will need to de-solder them, once they are removed gently bend and twist them to find the cracks again, place a bit of solder over the cracks and then sand them down so there flat.
Now that you have the metal leaf contacts removed, you can now see round chrome contact underneath. If the round contacts are dirty clean them thoroughly with a dab of dish soap. Next Clean them with 99% Isopropyl Alcohol, use a cotton swab to apply it.
If the round contact is pitted badly it maybe necessary to put a thin layer of solder on top of the round chrome contact, first prepare the surface with a fine sand paper and then put the solder on, next with fine sand paper sand down the solder to a smooth surface.
Re-solder the metal leaf contacts back on, make sure they sit high enough so there not touching the round contact underneath, but low enough so the Joystick can make the two pieces contact. See if the Controllers Directional work now. If they do then reassemble and use your controller. (I currently don't have any further instructions)
-Unresponsive Fire Buttons-
Disassemble the the button and clean the rails and slide with Isopropyl Alcohol. Put a bit of WD-40 or DeoxIT on the slide and both sides of the rail (the rail is the 3 flat extensions) and let it sit for about 5 minutes.(be carefully not to bend anything) Take the slide and carefully straddle it on a strip of paper and move it back and forth to remove any corrosion. Clean the corrosion off the rails with a cotton swab. If using WD-40 don't forget to clean up the residue with 99% Isopropyl Alcohol.
Put the slide back on the rail, apply a nice thin layer of dielectric grease or any nonconductive grease to protect against corrosion and friction. Put it back together. Test with a multi-tester using the 1K OHM setting. Press button in very slowly and make sure that contact is continuos from the point where it first makes contact to the point of being fully depressed. If the slide is damaged or rail is bent, contact can be intermittent and button is damaged. If you get a good reading...Solder it back to the board. (I currently don't have any further instructions)
If you have the revision of the board that has couplings holding the wire on then just reattach the coupling and do any soldering that needs to be done. Put a little hot glue along the surface of the PCB where the couplings meet the board. This will prevent them from coming off again.
-One Of The Keypad Buttons Works Sporadically-
Take the Controller completely apart. (5 Philip head screws.)
The Keypad itself has three layers, Two of which are very similar to a modern keyboard: A domed contact touches the layer underneath making a connection. The dome contact maybe cracked. If so, that contact needs to be replaced...
Use a blow dryer to warm up the glue holding down the second layer, this will be the dome contacts, and the final layer which you don't need to remove is the lower contacts. After repair use double stick tape to hold down the Number Pad. Be careful not to place the tape over the dome contacts, but beside them. (I currently don't have any further instructions)
-The Controller or Keypad Activate By Themselves-
The chip is located on the main PCB of your ColecoVision.(Texas Instruments SN74LS541N.) There are two chips(Octal Buffers,) one for each port. This IC needs to be replaced for the port that's malfunctioning. They are located at U19 for port 1 and U18 for port 2. You will have to open your CV unit up.(I currently don't have any further instructions)
-The Entire Keypad Not Working-
3- One or more wires maybe broken where the colored wires connect to the controller PCB. See the two sections above titled -Wire Broken From PCB- and section -Broken Cord-
4- Could be corrosion on the keypad traces, where they make contact with the Keypad Socket. Possibly corrosion on the Keypad Socket itself. Use a multi-tester and touch the front side of the Socket and with the other pole touch to the flat trace on the opposite side, see if you get a 1k OHM reading. If you do on all 13 locations on the socket then its not corrosion here.
If there is corrosion, then pull the Keypad out of the socket, clean the contact points with WD-40 or DeoxIT, slide a piece of card stock with WD-40 or Deoxit in/out of the Keypad socket several times to get grime and corrosion out. Reinsert the Keypad into the socket and test the Keypad.
5- The Keypad itself has three layers, Two of which are very similar to a modern keyboard: A domed contact touches the layer underneath making a connection. The inside of this dome contact or the layer if comes into contact with maybe corroded. Use a blow dryer to warm up the glue holding the layers in place, this will help to remove each layer. The top layer will be the number pad, the second layer will be the dome contacts, and the final layer which you don't need to remove is the lower contacts. Read on...
6- If the Number Zero (#0) is continually activated then it might
appear that the entire Keypad is not functioning. Check to see if
its corroded or stuck down. If it is then clean the domed contact
and the contacts on the plastic board. You might need to replace the
domed contact if it is cracked.(I currently don't have any further
Place a pole on the Keypad socket and another on one of the exposed traces, if these two locations connect then you should get a reading, if not the the break is somewhere in between. Narrow the search down by moving the poles closer together. Once you found where the break is use a Conductive Paint for painting electrically conductive traces and ground planes, it's usually a Pure Silver in lacquer based carrier. You may find the Silver Print Conductive Pen version easier to use(Radio Shack#276-037.) Lightly sand the exposed trace at the two points you intend to connect, do this until you clean off the surface, the trace will change colors to a silver appearance. Using the Conductive Paint apply it on over the breakage and let dry before testing the keypad. Do not try to use a solder gun and solder cause this will just melt the plastic and the trace.
Reassemble the Keypad, lay the layers back into position and warm them up with a blow dryer and work the layer so the glue sticks. If the Number Pad doesn't want to stay, use narrow pieces of double stick tape to hold it down. Be careful not to place the tape over the dome contacts, but beside them. You should see where Coleco originally has theirs. (I currently don't have any further instructions)
8- This next section is extremely uncommon and rare: The CV controller uses a diode matrix to decode the keypad, one or more diodes may be blown on the controller PCB if the entire keypad doesn't work. To test a diode you would have to un-solder one end from the PCB board, next run a 1k OHM through the diode, you might have to reverse the poles to get a reading, once you do then hold the poles the same way for each diode. If you replace one, make sure you put the replacement in with the correct orientation. (I currently don't have any further instructions)
The last resort is to find a replacement: The ColecoVision plastic foil keyboards seem to be an ordinary standard part, used for burglar alarm devices. They should be cheaply available in big electronic parts shops. The Keypad pulls out of the socket. (I currently don't have any further instructions)