Exchange tips and tricks for the Akai MPC4000
By Vendetta Mon Mar 27, 2006 7:03 pm
Yesterday i stared experiencing a problem with my pads.

Pads 1, 5, 9, 13 (All the right hand side pads) won't work.

Every now and again they respond. Do you think there's something wrong with the circuit baord?

Any advice is appreciated.

By drumtrack Mon Mar 27, 2006 11:43 pm
my upper right pad is too sensitive... :?


you could open up the mpc and see whats going on with the pads and/or contacts. its very easy
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By squareSOUL Tue Mar 28, 2006 6:59 am
Yeah Like he said, If you open it up you can see if the pads moved from where there corrosponding sensors are.
HOpe for you thats all it is. Fixing the beast is a drag
By djredhead Tue Mar 28, 2006 10:00 am
My pads on the mpc stop working everyonce in a while.

Currently, pads 1,5,9,13 and 4,8,12,16 work all the time. I spent most of yesterday pressing, massaging and other wise messing w/ pads 2,6,10,14 and with limited success over time was able to get them to trigger. Pads 3,7,11,15 still don't trigger. ;(

That is this week. I've jammed those pads for years and everyonce in a while some cr@p out.

So, thanks for the post about the sensors for the pads. I will see if they are lining up in my machine soon. Drag.

Anymore explanations about the pads would be appreciated.

;)

By benjamin9999 Tue Mar 28, 2006 11:02 am
when i got my used mpc4k, pad 16 was non-working.

the sheet with the sensors had a broken printed trace at the point where all of the lines turn 180 degrees to enter the connector on the board.

repair seems impossible, they are certainly the printed type and i tried three different ways to solder a patch onto it but it was just a mess.

each column of pads is supplied by the same +V line. so there are 4 +V lines, and 16 returns. sounds like the +V to that column is not there.

if you open it, check the traces - although i have no idea how you could mangle the machine to do it - my guess was that the one i had was this way from the factory and the previous owner just never knew.

a fresh sheet of contacts was $80 from VST and easy to install.

you can test the sensors out with a meter as well. you can probe at the points just before the connector.

there are some resisitors there for each return, i forget what is in the path of the +V signal, but there could be another simple component that has burned up. might be easy to bridge the +V from the next column somewhere.

it's no bad thing that the top pc board is nearly wire-wrap design, it's easy to trace and most of the components are easy to find and repair.

By drumtrack Tue Mar 28, 2006 5:49 pm
did you fix it or is pad 16 still broke?

By benjamin9999 Tue Mar 28, 2006 6:52 pm
yea it's fixed. all fresh sensors now. the sensors are layered in plastic, and come with a sticky back -- not pre mounted on the metal frame.

i took the old one off with a razor blade. it left the sticky residue but it's so thin it doesn't matter... the new one just goes on like a sticker.

there are little notches in the metal frame that help guide you.

inserting the flex-cable into the connector is the tough part, without damaging the printed cable. a little plastic "card" i peeled off of the old one gives it more strength to insert.

good as new
By djredhead Wed Mar 29, 2006 1:44 pm
Where did you get the contact sensors for the pads?

thanks.

By benjamin9999 Wed Mar 29, 2006 2:04 pm
i called up VST, they had them in stock and sent them out that day. if i remember correctly they were around $80. the rep i spoke with said the price had recently dropped on that part.

they're the same sheet used in every mpc, except the 1000 of course.

i didn't bother replacing the pads, i just washed mine with soapy water while i had it open.

vst

By djredhead Wed Mar 29, 2006 2:38 pm
I understand that VST has the sensors.

Could you post the website or phone number?

I can't wait to fix my pads.

thanks.

By djredhead Wed Mar 29, 2006 2:46 pm
thanks. lol