I just came across your site whilst trying to fix a couple of buttons on my MC909, and thought you might be able to help.

Two of the part select buttons (the orange ones that light up) are a not working 100% (they do eventually work, but I have to press them alot harder than the other buttons). I have downloaded the service notes, but it’s hard to identify the correct board to access (or the procedure) from there.

Do you know if its possible for for a mere mortal (ie me) to access these buttons to either clean the contacts (if this will help) or replace them (without me destroying the whole machine)?.

Really hope you can help.

I sometimes use an eraser for ballpoint pens to lightly sand the contacts on the pcb. Use a dry cloth to get any grit off the carbon part of the pad.

That’s just my 2 cents.

I am having problems with a few of the velocity pads. Trying to search for info to fix them got me here. Any thoughts on how to fix a pad that is registering several hits or not registering hits properly? Any info be appreciated. Thanks

Glad to be of help

i have been without the encoder/dial for quite some time now. it functions as long as i dial really slowly. however, in the meantime, i have grown accustomed to using the INC & DEC value buttons with ease. but i dont like knowing my 909 is busted, and sometimes my reflex still reaches for the encoder dial.

yeah first pass was rough enough, just getting under the hood of the 909 yielded so many screws.

your suggestions are very good. i like the idea of drawing a layout on paper.

for the record, this will be my first time soldering. do you suggest a bit of practice first? can a beginner handle this job?"

(removed his email address from the comment)

the part I got from mouser is EXACTLY the same as the one it replaced.

I used an electric screwdriver to do the job because as you might have seen, there are MANY screws there.

I also used a marker pen (a black one) to draw a circle where the black screws were on the main board. They have different size and threading space from the golden coloured ones.

Even better, you may draw a layout of the board on a paper and when you remove a screw, put it on its relevant position on the paper layout.

The above is to stress the need of making a note of the positions of the screws as there are 4 types of different sizes and/or threadings.

You may also need a set of pliers to place/remove the flat cables that connect the different components.

Last note. I didn’t completely remove the main board. I just raised it enough so as I can place the encoder. Removing it is an unnecesary overkill.

I ordered 3 rotary encoders from mouser so if you want, I could send you one (for free of course). (I will keep the other one, just in case…).

Hope to have helped a bit,

Aris

Hope to have helped.

Is Mouser’s replacement part better quality, or the same as the replacement part Roland sells.

Your post will be VERY helpful when i re-attempt this procedure, especially the part about the “order of removing components.”

What tools did you need for this job, other than screw set, solder pump, and soldering iron?

thanks for your response