I am relatively new to the DJ scene and the tools of its trade; I am no music professional (of any sort) but I do enjoy messing around with music in a number of ways. I have been spending a significant amount of time reading and learning in this forum for about 6 months and I thank the community for their willingness to share their experience and their assistance. Recently I purchased a second-hand NI Kontrol S4 through EBay (sold “as is” with a mangled USB connector and no power adapter) for a bargain price of $202 (a bargain assuming that it would work!). To make a long story short, I took the plunge and now I am the lucky happy owner of a fully working S4 (well, at least 99% working). In my previous readings I had seen a lot of interest/curiosity from various members about the “insides” and maintenance of the controller so I thought that I would share my experience with dismantling, cleaning and reassembling it.
WARNING: Obviously, warranty service was NOT an option for me and you should remember that opening your controller as I have done WILL undeniably, irrevocably and absolutely VOID YOUR WARRANTY! If you have any warranty coverage still left and your S4 is giving you trouble, do yourself a favor and send it in to NI for repairs.
Although the controller did turn-on from usb power (I used the advice provided by tekki in the thread http://forum.djtechtools.com/showthr...ighlight=broke after I unbent the contacts with needle nose pliers), it had a number of problematic issues: broken usb connector, dirty-sticky surfaces (some sort of sticky liquid had been spilled on it), many sticky buttons and poor fader/jog wheels response. The good news: most of these problems can be fixed with a good cleaning!
First I removed all the surface knobs and fader sliders (carefully prying them up with a flat head screwdriver resting on a piece of cloth to protect the controller’s surface), then I opened the back of the unit by removing the 22 screws (they really do not want you to open it up!, Pic 1), please note that the last of the screws is hiding behind the NI sticker (once you pop a hole through that there is NO turning back, no more warranty!). Inside there are a total of 6 separate boards connected by their respective wiring: (uppermost: Sound card, bottommost left: Phones/cue/vol/Mic board, bottom middle: Replaceable crossfader, leftmost: Deck board, rightmost: Deck board, middle: Mixer board, Pic 2). You can easily remove the sound card board by removing the two knobs from the back of the unit (input gains) and the two screws on the inside. I found it to be a good idea for me to take pictures of the process and label all the connectors with a numbering system as I disconnected them so that later I knew what connector went where… there are a lot of cables in there (Pic 3)…. The sound card board is also where the USB connector is located (Pic 3). I then removed the two bottom-most boards by removing their respective screws. The crossfader was absolutely disgusting (Pic 4), no wonder this unit had issues…. After removing the three boards (sound, cuemix and crossfader), then you can start the process of removing the deck and mixer boards (Pic 5). Again, NI does not make this easy at all. Even though there are a number of screws that hold the board in place from the inside of the unit you CANNOT remove any one of these boards UNTIL you have removed the pot fasteners from the top of the unit and you CANNOT remove those fasteners until you first remove the two metal faceplates off the decks and the middle plastic faceplate from the mixer This is probably the most frustrating and slow part of the disassembling process. Those faceplates are attached to the plastic frame by very stubborn glue. I was able to remove them with a thin kitchen knife and lots of patience (Pic 6, you do not want to rush this, you can end up bending the metal faceplates or scratching/breaking the plastic one, patience and manual dexterity are key, slow and consistent prying pressure from many different angles will eventually get them off). Once those were off, I removed the fasteners (washer and nut) from each of the pots in the mixer and then from the two pots in each deck (Pic 7). At this point I returned to the back to remove the screws from the MIXER board. I removed it by first disconnecting the cable to the left and right jogs (I had to make sure I labeled those wires since I did not want to confuse them) as well as the cables to the left and right deck boards. The mixer board came off with the four volume faders (these faders are not replaceable unless you are willing with unsolder them, Pic 8). Then I removed the left and right jog wheels by removing the screws that attached them to the circular plastic frame. I removed the left and right deck boards by removing their respective board screws (each of the locations on the boards where the board-holding screws are located is indicated by a picture of a screw next to its hole (at least that was helpful). After that I removed all the plastic button matrices (hotcue/samples and cue buttons, Pic 9). I was able to disassemble the jogs by first reversing the instructions provided by photojojo (http://forum.djtechtools.com/showthread.php?t=20326 ) and then I turned counterclockwise the small square board located in the middle inside the jogs. Those small boards are attached to a screw and once loose it allows the two halves of the jog to come apart (Pic 10), once the jogs were open, I was able to directly clean a bunch of sticky mess clinging to the inside and the grooved wheels with a DAMP cloth with warm water and diluted dish soap (60%water/40% soap).