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By plpl Fri May 21, 2021 5:14 am
My sp1200's main issues are sticky buttons and

the bank select button doesn't function, it's funny when I hit 3rd sound pad, the bank changes. I don't understand it, is it possible some soldering wrong with it?
For the basic cleaning, any tips? How can I take buttons off?

Much appreciated.

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By Ill-Green Fri May 21, 2021 8:21 pm
Wow, thats an ancient can of worms. If you know what to do, all props to you bro.

I do know the buttons are built as one mechanism so you won't be able to remove the plastic shell on top. You would have to either desolder or unscrew from underneath just to remove the whole piece completely.

And yeah, lots of naked wire, looks like it was "serviced" before because manufacturers like to hide wires and solder. I would resolder all that I can with fresh wire, clean it with some Contact spray, then spray clear acrylic all over the circuits to preserve them another 50 years. But thats me, nowadays I pour wood glue all over my circuits **WAIT UNTIL IT COMPLETELY DRIES BEFORE POWERING UP** only if you want to though...
By fobedafied Sat May 22, 2021 7:47 am
actually the cap of the "pad" comes off, but doing so isnt for those with heavy hands or who is lighthearted. the cap is the only part visible when assembled protruding from the "control surface" area. but disassembled the cap should be an easy recognizable part of the switch assembly. you want to get good upward pressure from both sides of underneath the "pad" cap with small screwdriver or knife or other thin tool without applying much down pressure if its assembled since you dont want to damage the "control surface". slow and steady but firm pressure upwards will dislodge the cap of the switch with some finesse and patience.

I actually paid Forat to do mine, which I requested new switches for all drum "pads". But he was very adamant about wanting to clean the serviceable ones and only replacing the ones which are absolutely necessary to replace as the switches are in very limited supply these days. I ended up only getting one switch replaced and the rest cleaned/serviced. All are now much more responsive feeling than before servicing, but you can slightly tell the difference between the old "pads" and the newly replaced one.

once inside the switch mechanism there is an arm type mechanism which lays across a spring and has a contact point on the other side. hopefully your spring is in good condition. if not you may want to order a new switch if you can locate one. anyway. blow the switch out with compressed air and/or swab out with a q-tip and some 91+% isopropyl to clean out any particulate debris which may have found its way inside over the past few decades. then you would want to identify the switch contact points and clean them up with either a deoxidizing solution and/or manually scraping with a metal tool so that the contact points are clean of any corrosion. the contact point and underside of the arm thingamajig need to be clean so as to allow unobstructed conductivity. reinstalling the cap to the switch mechanism should be self explanatory. just keep in mind that patience and being firm yet gentle are the key with these virtually irreplaceable machines/components.

there is also a "hack" of sorts which involves installing a paper/cardboard SHIM type piece of material inside the cap of the switch mechanism just to take up a very small bit of distance between the plastic cap of the "pad" and the arm mechanism that contacts the contact point beneath it so that it takes less pressure to actually make contact and allow conductivity between the 2 points without having to impact the "pad" with as much pressure as usual.

:-D :-D
Last edited by fobedafied on Sat May 22, 2021 7:53 am, edited 1 time in total.
By plpl Sat May 22, 2021 3:48 pm
Ill-Green wrote:Wow, thats an ancient can of worms. If you know what to do, all props to you bro.

I do know the buttons are built as one mechanism so you won't be able to remove the plastic shell on top. You would have to either desolder or unscrew from underneath just to remove the whole piece completely.

And yeah, lots of naked wire, looks like it was "serviced" before because manufacturers like to hide wires and solder. I would resolder all that I can with fresh wire, clean it with some Contact spray, then spray clear acrylic all over the circuits to preserve them another 50 years. But thats me, nowadays I pour wood glue all over my circuits **WAIT UNTIL IT COMPLETELY DRIES BEFORE POWERING UP** only if you want to though...


Thank you for the reply. I actually removed the top plastic and I learned that there's nothing to do with the plastic. Pads sticky due to the spring aged and it has to be the whole button replaced, it's basically some easy soldering work. I just can't find pad buttons for sale online, there's a seller on Reverb but he never replies my msg......
By plpl Sat May 22, 2021 4:28 pm
fobedafied wrote:actually the cap of the "pad" comes off, but doing so isnt for those with heavy hands or who is lighthearted. the cap is the only part visible when assembled protruding from the "control surface" area. but disassembled the cap should be an easy recognizable part of the switch assembly. you want to get good upward pressure from both sides of underneath the "pad" cap with small screwdriver or knife or other thin tool without applying much down pressure if its assembled since you dont want to damage the "control surface". slow and steady but firm pressure upwards will dislodge the cap of the switch with some finesse and patience.

I actually paid Forat to do mine, which I requested new switches for all drum "pads". But he was very adamant about wanting to clean the serviceable ones and only replacing the ones which are absolutely necessary to replace as the switches are in very limited supply these days. I ended up only getting one switch replaced and the rest cleaned/serviced. All are now much more responsive feeling than before servicing, but you can slightly tell the difference between the old "pads" and the newly replaced one.

once inside the switch mechanism there is an arm type mechanism which lays across a spring and has a contact point on the other side. hopefully your spring is in good condition. if not you may want to order a new switch if you can locate one. anyway. blow the switch out with compressed air and/or swab out with a q-tip and some 91+% isopropyl to clean out any particulate debris which may have found its way inside over the past few decades. then you would want to identify the switch contact points and clean them up with either a deoxidizing solution and/or manually scraping with a metal tool so that the contact points are clean of any corrosion. the contact point and underside of the arm thingamajig need to be clean so as to allow unobstructed conductivity. reinstalling the cap to the switch mechanism should be self explanatory. just keep in mind that patience and being firm yet gentle are the key with these virtually irreplaceable machines/components.

there is also a "hack" of sorts which involves installing a paper/cardboard SHIM type piece of material inside the cap of the switch mechanism just to take up a very small bit of distance between the plastic cap of the "pad" and the arm mechanism that contacts the contact point beneath it so that it takes less pressure to actually make contact and allow conductivity between the 2 points without having to impact the "pad" with as much pressure as usual.

:-D :-D


I did some cleaning before reading your comments haha. Yes, I'm pretty impressed by how friendly the design is, it's really easy to learn and deal with. Unfortunately, the cleaning didn't help too much. All springs and small metal pads looked good yet half of them performance bad. I think I have to order some buttons to replace them. Hope I can find some at a decent price...
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By Ill-Green Sat May 22, 2021 11:12 pm
Good work man. Yeah, those style of buttons are not made anymore but there are alternatives and function the same. Ebay has depending on how many pins, I bought a pack of 10 2-pin latching buttons for $7 or $8 bucks. Mouser.com is a good place and you might wanna try Small Bear Electronics, just google it, I don't remember the actual website, but its a little electronic store in my old neighborhood in Brooklyn, but they specialize in old parts as well as new alternatives. My other place is Newark.com tons of parts and where I get germanium transistors. Really a giant walmart kind of store for electronics. ;)
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By peterpiper Sun May 23, 2021 2:27 am
ouch! looking at the pics hurts.
I wouldn't turn this machine on untill completly cleaned.
And by saying that I mean desolder all pads (probably even every button) and faders, open the faders, clean them with isopropyl, open every pad and clean them if thats possible. BTW can you upload a pic of an opened pad? cause as far as I remember they look different (more flimsy) compared to these ones https://retrogearshop.com/products/e-mu ... -drum-pads
right?

The bank select error you got maybe caused by SW12 (PAD 1). This pad was serviced with bad soldering and to me it looks like there is a false bridge between soldering points. SW5 solderingpins also looks ugly and (from what I can see) wrong (bridged).

Would love to take care of this baby (after taking some sedatives to keep hands still/relaxed ;) )

I'd even think about buying a Weller soldering iron station. Good investment to get a 3000+ $ machine running flawlessly again.
By plpl Sun May 23, 2021 5:07 pm
peterpiper wrote:ouch! looking at the pics hurts.
I wouldn't turn this machine on untill completly cleaned.
And by saying that I mean desolder all pads (probably even every button) and faders, open the faders, clean them with isopropyl, open every pad and clean them if thats possible. BTW can you upload a pic of an opened pad? cause as far as I remember they look different (more flimsy) compared to these ones https://retrogearshop.com/products/e-mu ... -drum-pads
right?

The bank select error you got maybe caused by SW12 (PAD 1). This pad was serviced with bad soldering and to me it looks like there is a false bridge between soldering points. SW5 solderingpins also looks ugly and (from what I can see) wrong (bridged).

Would love to take care of this baby (after taking some sedatives to keep hands still/relaxed ;) )

I'd even think about buying a Weller soldering iron station. Good investment to get a 3000+ $ machine running flawlessly again.



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Hey Peter, I don't see much difference in buttons, do you know how much was it from Retro? And yes you are right, I resoldered the sw12 and the bank button is ok now, the bridge was messed up. I'd consider to have a soldering station, thanks for your advice:)
By plpl Sun May 23, 2021 5:09 pm
Ill-Green wrote:Good work man. Yeah, those style of buttons are not made anymore but there are alternatives and function the same. Ebay has depending on how many pins, I bought a pack of 10 2-pin latching buttons for $7 or $8 bucks. Mouser.com is a good place and you might wanna try Small Bear Electronics, just google it, I don't remember the actual website, but its a little electronic store in my old neighborhood in Brooklyn, but they specialize in old parts as well as new alternatives. My other place is Newark.com tons of parts and where I get germanium transistors. Really a giant walmart kind of store for electronics. ;)


Wow I'm gonna dig it! Thank you!
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By peterpiper Sun May 23, 2021 6:19 pm
Thank you for the pics. Yeah they look identical. I don't know the price but because of their business (retro gear) they are probably overpriced. It all depends on how much are you willing to pay.

You see the round deepening in the button cap? Seem the buttons can hold a LED. In the bottom part of the buttons are two holes for the pins. I wonder what kind of other devices (industrial machinery etc) the buttons have been used.
By plpl Tue May 25, 2021 2:19 am
peterpiper wrote:Thank you for the pics. Yeah they look identical. I don't know the price but because of their business (retro gear) they are probably overpriced. It all depends on how much are you willing to pay.

You see the round deepening in the button cap? Seem the buttons can hold a LED. In the bottom part of the buttons are two holes for the pins. I wonder what kind of other devices (industrial machinery etc) the buttons have been used.


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Yes man I tried to go deeper, the small button is easy to deal with. The little trigger inside is oxidized and turned black. Scratch it with dw 40 till it turns back into metallic. The stroke of the small metal plate is hard to lose even it has been serving for decades. Having some patience and people can save some money.