Dead & Unresponsive MPC Button need New Tact Switches
This is a quick DIY for repairing the tact switches on any MPC 500, 1000, 2500.
The process is quite easy, but if you do not have any soldering experience I would recommend paying another to do the repair or purchasing a pre-made board (either new or refurbished). I will post some pictures below of boards I have come across which the owner(s) should of definitely not touched.
The method I show below is for removing the solder, dependent on the abuse of the board, cutting off the tact switches from the top side of the board works great as well. Just don't cut the prongs so short you have no grip to grab onto when you heat up the solder from the back.
Tools for the Job
Pretty simple tools that any DIY'er should have.
- Soldering Station - No, switches and potentiometers can not be "clicked" in or glued down. You can probably get away with using a $10 solder wand from your local Radio Shack (are they even around anymore?) or Harbor Freight, but unless you are heavily practiced with how it preforms, it's probably not a good idea.
- Solder - Ace Hardware or Autozone, I can't seem to find it anywhere else locally, so if you have some time to waste order online.
- Solder Wick - Again I can't find it locally so I just order in bulk from China. You can also use a solder sucker (never had any luck using those, besides for sucking gobs of solder from lug post). Or....
- Dremel - A dremel works great for cutting off the legs on the component side of the board, then heating up the remaining pin and pulling it out, but if the solder closes up the hole and you don't have solder wick you are a little up s**t creek as the repeated reheating is going to burn off the solder pad.
- Flux - A nice shoe polish size container of flux will last you ages, again I would recommend buying online. I stocked up on Worthington when Home Depot/Lowes had it on close out and it has worked great for all my projects.
- Toothbrush, Rubbing Alcohol, Paper towels. - All can be found around the house.
Don't Forget About Your MPC Parts and Stuff!!!
- Tact Switches
- Encoder - (might as well change it out while you're in there)
- Fresh Screen
- Add some Tape or Rubber to those non-responsive pads!!
Remove the MPC500 Top cover / Faceplate
There are a total of twelve screws between you and the access needed to to remove the top cover. Three on the front side panel, Three on the back side panel and six on the back, each side having three to remove. the two screws in the top center do not need to be remove or loosened. They hold grounding post on the inside of the unit to the main board. Leave them alone.
Once all twelve screws have been removed. wiggling the unit should pop up the top. With the top of the unit facing you, gently lift up the left. side. If it does not easily lift up, look in the crack and you will see the ribbon cable that the faceplate needs to be worked around. No need to go Hulk on the b***ch. once the left side is up you can easily slide it to the right ad lift it up.
The picture below shows the approximate location of the screws. Just remember when putting it back together, the red screws are flat on the top, the yellow screws are curved, an again, no need to go Hulk on the b***h, it's plastic, finger tight will do.
Removing the MPC-500 Control Board
First pull off the Jog Wheel Knob.
The cursor buttons have small tabs on the left and right side. Gently pressing the tabs inward while pulling up the plastic button block is the best way to get it out. A small screwdriver is recommend so the plastic tabs do not get bent.
You will now have the following five screws to remove (picture below) and two ribbon cables. Again, very gently work the cables out from side to side. They will unclip and pull out, no need to try and bend the clips with a screwdriver.
Once you have the board out you can press out all of the plastic buttons from the backside for cleaning. This machine is old so you know there is staph, sh*t, boogers and all kinds of stuff on those buttons. Just clean them.
Desolder, Cut, or Suck
If you are de-soldering, or using a solder sucker your board should look as below at this point. you can see that all the solder has been removed, with the top to solder joints left for visual reference.
None of the pads should be peeled up or missing from the board.
If you cut the switches off from the other side of the board. Pinch the remaining leg with some tweezers from the component side, heat the solder (with fresh solder on your iron) and pull them out.
Push out the old switches.
At this point you can continue to remove old solder (be careful because the solder pads on these boards can only take so many reheats) or clean the board with some paper towel and rubbing alcohol. Try to get all the un-cleaned flux from the factory off.
Gently push in your new switches, apply a little flux and solder them back into place.
Clean the melted flux off with a toothbrush and rubbing alcohol to get the board clean. No need to get it perfect as you more than likely just cleaned it better than the factory.
Double check that none of the solder joints are touching adjacent pins and put that bad boy back together.
If you don't Know what you're doing......
If you don't know what you are doing, please don't try it or you will be in a situation as below needing to scrap your board, add jumper wires or flat out just buying a new board.
Manuals For the MPC500
This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.
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