In desperate need of help please, my jogwheel is gone crazy.

Hey guys, my jogwheel has rendered my mpc pretty much useless. Let me explain the problem the best I can. Say I am on track no. and I turn the jogwheel 9 clicks right, which should put it at track no. 10. Instead of going to 10 itll go to around 5 or 6 and then extremely quickly go down to zero. I had this problem once when I was changing out HDD's and I put the old one back in and it went back to normal, but this time I tried that, totally removing the HDD, removing and re seating ram , everything and no luck. I am extremely bummed about this cause I cannot make music, can anyone help me with this. Thanks so much

Replace the jog wheel.

Does that sound too obvious?

LOL. I was hoping for a answer that did not involve soldering, since i dont know how to solder. Thanks though, a new jog wheel it is i guess.

and do i need to replace just the jog wheel or a whole new PCB Jog wheel assembly? Or do i need a new rotary encoder???

It does sound like the sort of fault that comes from a worn out rotary encoder - seems like the logic circuits can't tell which direction the encoder is being turned so it jumps around crazily.
What happens when trying to set start or end points of a sample using the jog wheel, can you tell me what's happening to the values?

I had this problem on an E-mu sampler so I can't guarantee that it's the same thing here.
If I turned it really really slowly it would work a bit.
In the E-mu the encoder was totally stuffed, the back plate on it had become loose over time, probably as a result of pushing down on the wheel. New part cost me $8 but I had to solder it in.

Try re-initialising the MPC back to factory settings as well.

If you need the encoder ($50 but no soldering needed for this):
http://www.mpcstuff.com/1al4016a504a.html

Thanks so much for the reply I really appreciate it. Right now the 4k is upstairs so I have to wait until tomorrow to check the loop point thing, but when I change the values slowly it does work, so it sounds like the same thing. I will post my findings first thing tomorrow.
Is the jogwheel itself soldered onto the rotary encoder, because I dont want to rip it off and have another issue. If it's not how do I go about taking it off so I can just order that part since I have no idea how to solder.

wait though, maybe replacement is needed... but I highly suggest getting some contact cleaner and spraying some in the encoder. for example: asalco contact 2000. You can grab a can of this stuff for under 10 bucks (closer to 5 bucks) and it's always nice to have around for cleaning pots and knobs etc... once that is dry then try her again to see... maybe it's just dirty and isn't making proper contact each click.

I don't think contact cleaner is a good idea, because AFAIK this encoder in the MPC 4000 is an optical encoder - there are no contacts in it at all. A small LED shines onto a reflective disc that is attached to the shaft that you turn with the knob.

Looking at the picture of the encoder that MPC Stuff has it sure looks like an optical encoder (large square body with 4 wires). The mechanical encoders have a much lower height body and only 3 wires as they don't need a voltage source to operate like an optical one does.

Although, I guess if the encoder is stuffed then it isn't going to get worse by spraying some cleaner in.

The jog wheel that you turn should just pull off like a volume knob does, it isn't soldered on or anything. The problem here is how to get hold of it as it sits flush with the cursor controls. Then there should be a nut about 10mm in size that is holding the encoder with it's little circuit board into the front panel. Once that nut has been loosened off and removed the encoder should be able to be dropped out the back of the top panel.

I can't work out from the service manual whether you can get the encoder out just by opening the MPC up like normal or maybe the whole top panel has to be removed. Maybe to even pull the jog wheel off you have take the top layer off the front panel. I don't want to try and pull my jog wheel off because the encoder is not in great shape either so I'm being as gentle as possible with it at the moment.

A quick search using the part number from the service manual finds this:
http://datasheet.octopart.com/REC16B25-201C-Copal-datasheet-38473.pdf

So definitely an optical encoder (which is great because they last way longer than the mechanical ones). This means that using cleaner in it will bugger it up even more than it is already.

**Edit - I found some of these optical rotary encoders for sale around the $18 to $20 mark, so $50 from MPC Stuff with the PCB and wiring already on it is actually a pretty good deal IMO, particularly if you would have to get a tech to solder in the bare encoder for you.

Just wanted to let you guys know I ordered the pcb with wiring(super fast shipping from mpcstuff) and no soldering was needed. Installed it and everything works back to normal, huge sigh of relief! Thanks MPCDawk for your quick response, and thanks Clint for being a smarta$$

tomc3084 wrote:Just wanted to let you guys know I ordered the pcb with wiring(super fast shipping from mpcstuff) and no soldering was needed. Installed it and everything works back to normal, huge sigh of relief! Thanks MPCDawk for your quick response, and thanks Clint for being a smarta$$

Great news!

How did you get the encoder assembly off the front panel, did you have to remove the top layer?

tomc3084 wrote:thanks Clint for being right

Corrected for you.

Never overlook the obvious.

Good to hear you got it sorted.