Okay, so I've managed to sort this out so thought I'd share it here in case anyone else has the same problem.
In the end I just had a go myself and replaced the rotary encoder. To do this I would strongly recommend getting hold of a few things:
Desoldering Iron
Some basic soldering assembly and repair tools
Lead free solder with flux core
Soldering Iron
I never managed to work out the exact properties of the rotary encoder I was trying to replace. If it was working I probably could've worked it out with a multimeter, but hey. In the end I bought one from ebay like this:
Pinouts:
Encoder A output
Encoder B output
Common
2x SW - 'Select' switch (activated when shaft pressed on top)
Specifications:
Size (L x W): Approx. 15 x 11mm
Shaft Diameter: Approx. 6mm
Rotary Shaft Length: Approx. 12mm
Shaft Full Length: Approx. 20mm
Output: 2-bit gray code
Closed Circuit Resistance: 3 ohms maximums
Max. Rating: 10 mA @ 5 VDC
It works fine but is not exactly the same as the one I replaced. Each notch turned advances the programme by two, though you can still advance one programme by turning a half notch. Easier than perhaps it sounds. The other difference is that the shaft is slightly longer so the knob protrudes a little further than before.
Don't forget to buy one that also acts as a push switch otherwise you won't be able to change bpm!
So with all that in mind:
Step 1: Disassemble the Kaossilator
- Remove the knobs (programme, programme volume, input colume, gate arp) by pulling them off gently.
- Remove the three screws on the rear of the unit (where line in/out etc are). Note one screw is longer and the other two are black.
- Remove the four screws holding the base plate on to the bottom of the unit, take care not to tear the copper strips the are attached to the two screws at the sd-card end, and remove the base plate.
- Remove the four screws fixing the two top layer PCBs to the one underneath. Pull the larger PCB up and the smaller one (with headphone jack and volume) will pop up too. When they come away take care as they are attached with a ribbon cable. Detach the ribbon cable from the top layer PCB and put the top layer PCBs to one side.
- Unscrew the lower layer PCB (about 12 screws)and detach the second, thinner ribbon cable
- Pull the PCB towards you to remove, you may have to move one of the switches to get it to pass through the hole in the casing. Some of the buttons may be stuck to the PCB, if they come out just put them back in their place in the casing rather than leaving them attached to the PCB
Step 2: Desolder the rotary encoder
You really should use a desoldering iron for this. It will make life a lot easier and reduce the risk of burning out any small parts.
- Locate the broken encoder on the PCB, ideally clean the solder with some isopropyl alcohol, but don't worry about this too much.
- Remove solder with the desoldering iron. There are 7 pins in total (5 working and 2 more to hold it to the board). If you have some soldering tools try to wedge something between the encoder and the PCB so when you remove solder it starts to prise it off the board. If you make a mess of the board you can try using a small wire brush to clean it up
- Once you've removed as much solder as possible, you should be able to remove the encoder by bending its pins and wiggling it off the board.
Step 3: Solder the new rotary encoder
- Simply pop it in and solder all the joints. Easy!
Step 4: Re-assemble the Kaossilator
- Reverse of step 1. Take extra care to make sure the ribbon cables are firmly seated in their sockets. I suggest just using a few screws first, make sure all the buttons and switches are pressing properly and then finish off with the remaining screws.
- Make sure the copper strips are screwed down between the casing and baseplate!
And that's it.
P.S the "no audio out" problem was because I forgot to turn the programme volume back up...ahem.
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