Post your questions, opinions and reviews of the MPC1000. This forum is for discussion of the OFFICIAL Akai OS (2.1). If you wish to discuss the JJ OS, please use the dedicated JJ OS forum
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By Sense-A Mon Sep 17, 2018 2:40 pm
I have a fairly new MPC Stuff MPC 1000 pad upgrade. It included the pad sheet sensors and the PCB board. Unfortunately, it is outside their 90 day warranty.

It has rarely been used and shows no signs of any wear or tear. It's been safely in storage most of its life.

My problems are isolated to pads 1 and 2.

Unfortunately, I am rarely getting any velocity on pads 1 or 2. However, the pads receive pressure correctly. Also, sometimes pad 1 triggers pad 2 and pad 2 triggers pad 1. This is erratic. What sort of scenario would allow correct pressure readings but not velocity?

My suspicion is that there may be some kind of grounding issue. I wonder if the PCB board that gets tucked beneath the pad sensor tray is shorting to the chassis. However, if that were the case then all the pads should stop working. It could one or two bad solder joints on the PCB board, but they all appear okay to the naked eye. The ribbon cable also appears to be correctly seated. I tried reseating it and no change. There are no apparent cracks or scratches in the conductive leads that go from each pad to the end of the ribbon cable...

I wonder if the conductive leads from pad 1 and 2 are shorting to each other somehow....

I've tried both JJOS2 and free Akai OS. The problem is same regardless of which OS.

I am trying to isolate the problem to either the sensor sheet or PCB board.
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By Sense-A Tue Sep 18, 2018 10:32 pm
Update:

So it seems that pressing pad two selects pad one and selecting pad one selects pad two!

And here is another oddity:

The pressure for both pads 1 and 2 is constantly at 14 with sensitivity in JJOS at 23. When I turn sensitivity all the way down it still constantly registers a 1. In other words, pads 1 and 2 are constantly sending pressure data to the OS.

This leads me to believe that either:

1. The sheet is malfunctioning and acting as if it is being pressed down, constantly.
2. There is a short between the conductive tracks...
3. There is a short on the PCB board.

In other words I'm still mostly at square 1, only with a better description of the symptom of the problem.

Pressure still registers when I hit the pad. But velocity rarely works for either pads 1 or 2.

The rest of the pads work fine...

I'll keep researching and testing...

Searching the forum for this problem is difficult because most of the pad issues on this forum refer to the old style pads.

This is very frustrating considering that I paid about $170 to MPC Stuff for new pads, expecting to not have to deal with pad problems for a long time, and with less than 8 hours of usage out of the new pads they are already acting up as bad if not worse than the old style pads.
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By Sense-A Fri Sep 21, 2018 1:48 pm
Last night I was pounding away at pad 1 and it seemed to have loosened up and become more responsive. Pad 2 was the primary culprit. I noticed that this particular pad is located where there is a notch in the metal plate the pad sheet is taped to. The notch interrupts what is normally a taped down surface. I wonder if there is an air/suction problem that keeps pad 2 pressed/stuck down.

When I hit pad 1 or pads 3-16 the MPC 1000 reverts back to pad 2. It's as though it is sending a constant signal (simulating someone holding the pad down).

Pad 2 actually works if I hit it in the very bottom left corner. Otherwise it doesn't respond normally.

:idea: I'm wondering if this might be a solution: viewtopic.php?f=29&t=159419

"the reason why these sensor fail is something to do with air in the sensor plate.
the air works as a spring, over time the air is gone and leave only suction. no spring and the top layer of the sensor is constantly touching the the bottom layer."


A small slit near the black square space, or else slits in the pad sheet (not cutting the conductive tracks) might allow enough air in between the layers to relieve the vacuum-like suction...

I've poked around with the multi-meter and the PCB board seems to be transferring signals from the input cable to the output cable correctly.

UPDATE!!! FIXED!!!

The repair to the MPC 5000 in the video worked!

I made two very small slits in the pad to allow air in between the carbon and the conductive tracks. Now pads 1 and 2 behave normally. Each of the two cuts I made was only 5mm long. I did not cut anywhere inside the black square. I cut horizontal in the channel that allows air to travel between pad 1 and 2. I also made a small cut in the top right corner of pad two (just outside the black region).

Image

The arrow shows where I believe air escaped from beneath the pad. I believe that while in storage for over a year, and not being used, the MPC 1000 expanded and contracted with the changes in temperature. The change in temperature had the same impact on the space between the pad contacts as it does in your automobile tire.

The two red lines depict the locations where I made the cuts.

Everything is working great now. One thing I am considering is placing two small pieces of scotch tape / packaging tape over where I made the cuts to seal them back up. That could, however, recreate the problem. The two cuts increase the risk of dust or moisture working itself into and underneath the pad. This is very low risk and it is just as likely that the adhesive of the top and surrounding areas will reseal itself.

So let's review the symptoms:

Pad keeps triggering by itself.
Pad is sending a constant velocity or pressure signal.
You have problems with two side by side pads (i.e. 1 and 2, 3 and 4, 5 and 6, or one particular row)
A pad is unresponsive or only triggers a percentage of the time or in one corner

Here is what my problem looked like. Pad 2 was sending a constant pressure signal even when pressure sensitivity was turned all the way down:
Image

I would only attempt this repair after you've verified that the PCB works and that the cables are working. You can do this by using a multi-meter in the continuity setting. In other words, don't cut the pad sheet unless you've ruled out other possibilities the best you can.

Here are things to check:

Make sure this ribbon cable is correctly aligned:
Image

Also inspect the ribbon cable for any cracks or scratches. Look at the grey conductive tracks that carry the signal.

Check the PCB board for any shorts, scratches, bad solder joints. You can also check for continuity from one cable input to cable output. Trace the signal through the pcb and check for continuity.

Image

I hope that others who experience my problem are able to fix their MPC 1000's too. It was stressing me out and I didn't want to spend another $80 on a pad sheet that I had just bought and barely used.
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By Sense-A Fri Sep 21, 2018 2:25 pm
I was way beyond the 90 day warranty period, although I had rarely used the MPC 1000 at all since installing it.

I did notice that there were stickers on the unit marking that it had been inspected. This is indication of good quality control. I was also impressed with the precision MPCstuff or else their supplier must have used in cutting the ribbon cable. It fits perfectly in the slot on the PCB and there isn't much margin for error. The pads were taped down with strong adhesive and properly aligned. Again, there isn't much margin for error. There's raised areas which are meant to allow a little bit of air/space for each pad.

My only mild criticism is that the stock grey cable inside the MPC 1000 doesn't quite reach the white connector on the PCB if you screw the pcb to the two designated holes on the underside of the pad tray. I believe MPCstuff does, however, provide a longer cable to counter this issue. Switching out that cable involves more disassembly and increases the difficulty of the upgrade. Leaving the PCB loose under the tray doesn't seem to pose any problem and there is no high voltage going through that PCB that I am aware of.

I feel like I should sell my old mpc pads and tray for someone else to recycle or reuse. They're stuck inside a shoebox somewhere. About 12 of the pads still worked when I finally replaced it. I had tried various remedies on the other 4 pads and eventually got tired of repairing pads and opening the MPC up more than I played it.

Now I am moving on to other Akai projects. I am replacing transformers in an S1000 and S1100 with modern toroidal transformers (to convert a Japanese 100V version to US 120V and a UK 240v version to US 120V). I also noticed that one of my S1100 samplers has an internal connector on the SCSI card whereas the other S1100's SCSI card only has the external connector. However, the SCSI card has the area on it for an internal SCSI connection to be soldered on. I need to do research to find out if different versions of the SCSI card for Akai S1100's existed. I might pull both out, do side by side comparisons, and write up a tutorial how to upgrade the one with only an external connector to have both an internal and external connector. I never could find a useful schematic or detailed service manual for the Akai S1000. One exists, but it really just lists part numbers, not voltages and schematics.

I have lots of extra SCSI hard drives and want to add internal SCSI drives to all my Akai samplers. I'm somewhat concerned with the heat and noise that internal hard drives might introduce. I cannot afford to put SCSI2SD interfaces in all the samplers.

I'm willing to trade an SCSI hard drive for an akai s1000/s1100 AES/EBU expansion card.

I also have a GoTek floppy emulator installed in one of my Akai S1100's and will attempt to install GoTek drives in the others.

I have a Akai S3000XL that I want to trade or sell. I love it but I don't use it enough to justify keeping it.

Now that my MPC 1000 is working, I am going to sample some of my romplers and drum machines into it and build some valuable drum kits. My MPC 1000 is important because I have lots of samplers with no sequencer inside them. The MPC 1000 is my go to sequencer and my go to drum machine. I have lots of keyboard samplers that work well as midi controllers and have sequencers, though, not as good as the MPC 1000's.
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By Sense-A Sun Apr 12, 2020 10:27 pm
It's been well over a year since I documented this problem. And it's been about 3-4 months since I fired up the MPC 1000. Well, I turned it on today and now I am having the same exact problems I discussed having with pads 1 and 2 with the pads above them 5 and 6.

So again, after months of storage and no use, I think the pads may have formed a sort of vacuum. I will attempt to do the same repair that I did on pads 1 and 2, making two small escapes for suctioned air, and see if pads 5 and 6 stop ghost triggering. Pads 1 and 2 and pads 9 and 10 above often ghost trigger 5 and 6 and 5 is ghost triggering itself. Adjusting velocity thresholds for pads 5 and 6 in jjos2xl wasn't enough to fix it.

I will report back. (I still owe you guys pictures of the MPC 4000 I restored to beauty).

Edit> Oh yeah. About the Akai S1100. I switched out a 240 volt transformer with an after market, high quality and efficient toroidal transformer I bought online for about $25. So the Akai S1100 works on USA 120 volt now. I have a step down transformer for an old japanese Akai s1000 i have. But if anyone ever wants help converting a japanese 100 volt or European 240 volt device to USA 120 volt I might be able to help. You have to measure or get a schematic for what the transformer is supposed to output in voltage for your instrument and go from there.
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By Sense-A Thu Apr 16, 2020 12:54 am
Fixed it. Works as good as new and I made a couple beats last night.

A few tips. Make a cut in the area similar to how I did with pad 2 above. top right corner, but under the grey electrical contact. The cut should only be 1 or 2 mm in length, just enough. The entire thing is delicate.

Before cutting anything, try something easier. Make sure the casing isn't causing issues, or the rubber pads themselves. Test the pads with the case and rubber pads off.

I doubt I am the only one whose MPC acts grumpy being turned on after many months of storage.