Problem: Some pads fail when top panel is re-attached?

Hi folks.

Got a problem with my 4K, any help really appreciated...

I just installed new pad sensors, and one set of corx which are attached to the (factory) pads.

* With the top of the MPC off, all the pad sensors work when tapped.

* When I put the pads on over the sensors, all the pads work

* And all pads *still* work when I put the top back on the MPC, so that all the knobs stick through the holes in the top panel and the panel is resting where it’s supposed to be.

BUT ... after I then re-install all the screws that hold the top panel in place, and the four Allen screws around the pads, certain pads don’t work.

The first time I locked everything down, it was 1 or 2 pads in the left column that didn’t work. After opening the box up, re-checking everything, then re-attaching the top, the left pads were all fine ... but now 1 or 2 in the right column didn’t work. (The center 8 pads always work.)

The pads that don’t fire are consistent until I reopen the MPC—it’s not random.

———————
Very strange—I can close the top, but not put in the screws, and everything works. Tighten the screws down, and trouble starts.

Any ideas? I’ll call MPCStuff if I have to, would rather not.

Thanks!

Check the pad’s ribbon cable connector is fully inserted and seated.

JUKE 179r wrote:Check the pad’s ribbon cable connector is fully inserted and seated.

Thanks for that.

I pulled the box apart again, and did my best to get the ribbon seated as far in as possible. Also got rid of the original plastic strip that’s supposed to stick to the ribbon to make it thicker—the adhesive was weak—and used a couple thicknesses of packing tape in the same place, to make a tight fit for the ribbon.

At this point, everything is fine except that Pad 13 (Upper Left) will act up if the Allen screw near it is too tight. Tighten it a little more and Pad 13 goes dead. Whether this means the left edge of the ribbon isn’t seating tightly, or that something stranger is going on, I don’t know.

I’m gonna play it as it is. Just got a Live, but I’ll ride the 4000 ‘til it drops.

Thanks again for your help!

It sounds like the screw is creating some change in how the ribbon cable interfaces with the mounting bracket. You might want to play around with varying the amount of tape you use in there as it might causing the ribbon to bow or bend a bit causing a faulting connection. Sometimes thinner is better in these kinds of situations

This stuff certainly isn't too complicated, but it can certainly feel like it when it gets fiddly like this. As long as the connector isn't broken or damaged, you ought to be able to get this to work. Stay patient and avoid doing things that would permanently modify or damage it.

NearTao wrote:It sounds like the screw is creating some change in how the ribbon cable interfaces with the mounting bracket. You might want to play around with varying the amount of tape you use in there as it might causing the ribbon to bow or bend a bit causing a faulting connection. Sometimes thinner is better in these kinds of situations

This stuff certainly isn't too complicated, but it can certainly feel like it when it gets fiddly like this. As long as the connector isn't broken or damaged, you ought to be able to get this to work. Stay patient and avoid doing things that would permanently modify or damage it.

Yeah, that seems like the logical explanation—particularly since iirc the pad that was acting up has its trace on the left end of the ribbon, where it could lose contact a little more easily.

Since all the pads are working consistently now with the front panel screwed on, I’ll probably leave well enough alone until something acts up.

Thanks for your thoughts about tape thickness—I’ll bear that in mind if things go south again.