The place to share knowledge about upgrades, mods, customisations and all other cool DIY projects for MPCs and other music equipment.
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By proppa Wed Apr 10, 2013 10:34 pm
greets all - though there's been several of them i've yet to find one comprehensive thread regarding tact-switch replacement for mpcs. i'm hoping this thread becomes a summary of the process.
to be clear: i have yet to open the lid of an mpc much less go to work on the internal electronics - but i'm trusting there are others like me both dealing with decaying mpc's and yet to take the internal-electronics plunge.

the information i've been collecting here from the mpc-forums threads applies to the mpc 2500 but from what i understand extends to (most?) other models as well - any experienced users please feel free to add or correct info in this thread.

here's what i've got so far:

main tacts:
ALPS-SKHHAKA010
OR:
Omron B3F-1020

transport (play, stop, record, etc) tacts:
Omron B3W-1000

tools needed:
phillips head screwdriver
new tacts
lead free solder
soldering iron specifically for PCBs (lower heat)
de-soldering braid and / or:
de-soldering sucker gun
needle nose pliers
jewelers screwdriver

2500 case removal:
http://www.youtube.com/watch?v=RhYqySGH-7k

video showing replacement of mpc 3000 tacts:
http://www.youtube.com/watch?v=K6XbdAAQj1s

de-soldering instruction:
http://www.epemag.wimborne.co.uk/desolderpix.htm

collected notes:

do not pull the old tact switch out with pliers directly after heating-
always use a desoldering pump otherwise you run the risk of destroying the solder connections on the circuit board.

(modified step via sciguy)
Best way IMO to desolder is skip the solder sucker, and go for desoldering braid. Once you get the hang of using it right, you can get basically 100% of the solder out of the joint, and you can just pull the part out, leaving nice clean PCB holes behind.


anyone else have further tips / techniques / corrections?
Last edited by proppa on Wed Apr 10, 2013 11:00 pm, edited 1 time in total.
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By sciguy Wed Apr 10, 2013 10:47 pm
proppa wrote:
to save time in getting the old tact switches off clip the leads at the top where they connect to the body and then remove them one leg at a time when de-soldering the thru hole.


I would not recommend this.

Best way IMO to desolder is skip the solder sucker, and go for desoldering braid. Once you get the hang of using it right, you can get basically 100% of the solder out of the joint, and you can just pull the part out, leaving nice clean PCB holes behind.
Cutting the legs gets irritating, it makes it harder to get it out, because the solder will tend to cling onto the leg in the PCB hole. You'd have to do some funky maneuver with pliers or something.

But do whatever works, this is just what I find easiest when (de)soldering.
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By proppa Thu Apr 11, 2013 1:36 am
SimonInAustralia wrote:
Are they the same as the originals, or better?


both are rated at an operation cycle of 1,000,000

(alps) http://www.alps.com/WebObjects/catalog. ... KA010.html

(Omron) http://www.onlinecomponents.com/omron-e ... p=12043512

unless my 2500's were badly installed i doubt they had life cycles that high

i've put countless hours on my 2000classic and to this day have no button / tact issues whatsoever - i'm hoping the alps / omrons are akin to the original 2000's parts
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By SimonInAustralia Thu Apr 11, 2013 10:47 am
Thanks for the info.

I have a couple of bad tacts on my 2500, so might as well do them all while I am in there.

From the amount of bad 2500 tact switches you read about, they must have used some cheap and nasty switches.
By konc3pt Thu Apr 11, 2013 11:49 am
SimonInAustralia wrote:
proppa wrote:main tacts:
ALPS-SKHHAKA010
OR:
Omron B3F-1020

Any idea if one is better than the other?

Are they the same as the originals, or better?



Replaced entire right PCB with these n can say they operate smoother, more responsive n less clicky