puslar123

Casio SP33 is a 3-Pedal Unit which was an option for Casio PX150 and PX350 (should be used with CS-67 stand stand). My sustain pedal recently broke (specifically, the part of the plastic body which holds the axe for the sustain pedal cracked), and the sustain function no longer worked reliably. (From my google search, this seems to be a fairly common problem.)  I looked around, and it looks like it's no longer possible to buy the pedal assembly (it's discontinued). 

 

So I ended up fixing it myself, by doing some metal work (cutting / drilling) on a small metal bracket from a dollar store. I think these photos explain the process well.

 

The pedal works now, but it remains to be seen if the fix will last - there is always a chance that now the plastic body itself (where the metal bracket attaches to) will eventually crack.

 

 

Thanks!

 

As I mentioned in my OP, the single key contacts are apparently only for the sustain functionality, though of course Casio in addition can use them in a smart way to compensate for issues of the double contacts.

I am glad my post helped other people!

 

An update - it's been more than a month since I fixed my issue, and the keyboard worked well all this time. Just in case I ordered more replacement contacts (to be able to completely switch to new contacts if needed), but so far the rest of the old pads worked fine.

Yeah, sorry about that! At that time I just wanted something large and soft, and wasn't too worried about picture background

I don't think dirt can cause it (these contact pads are well protected from dust - see my photos in the post). I successfully fixed the same issue on my Casio PX-135 by replacing bottom (double-padded) contact strips for the defective keys. See the detailed description here:

 

 

It is for PX-135, but PX-130 should be very similar.

 

The cost to replace all seven 12-key stripes is 2$ x 7 + 13$ shipping to Canada = 27$. It wasn't in stock, but it was delivered in one month. The fix takes half a day (to disassemble and re-assemble the keyboard; the fix itself takes seconds.) No special tools are required: only a few screw drivers, and lots of patience and attention.

 

If you pay somebody to do this, the cost can easily be 2-3 hundred bucks as it takes a lot of time to disassemble/assemble the keyboard, even for professionals.

 

EDIT: Of course it is entirely possible that your issue is caused by a different problem (e.g. just dust). But given how cheap these replacement contact pads are, and how much time it takes to disassemble and re-assemble the piano, it makes a total sense to have them in hand before attempting the disassembly.

 

Update (and success story!).

 

I finally got the replacement contact pads from PacParts (I ordered a few different kinds as I wasn't sure what I needed; it wasn't in stock, but I got it after one month; I ended up only needing the long double-padded stripes, which apparently measure velocity = loudness of key strokes: http://www.pacparts.com/part.cfm?sku=91087274212 )

 

Here is the disassembly of my Casio PX-135 piano. The most time consuming was removing all keys, one by one, using two small flat screw drivers, and (as far as I recall) removing white keys first. This is after removing all keys:

 

 

 

 

Closer view of the problematic keys (marked with red). As you can see, no obvious issues here:

 

 

 

 

 

Next I removed the top layer of boards with single-padded contacts. (My test showed that these contacts are only responsible for the sustain feature, and have nothing to do with triggering a sound or its volume, so I knew they are not the culprits.)

 

 

Close-up on a bad key: nothing suspicious here either:

 

 

 

Finally when I removed the second layer of boards, I discovered stripes of double-padded contact stripes. I instantly saw the culprit: the key which I knew just got "stuck" at the highest volume had the corresponding double-padded contacts literally stuck in a pressed position. (Unfortunately I was so excited that I found the culprit that I forgot to take a picture of it.) Otherwise nothing obviously wrong with it - contact pads were clean and not worn out, no sticky stuff inside the pad. My only explanation is that perhaps these stripes are defective (may be too thin rubber; or perhaps wrong composition which deteriorated quickly).

 

The PacPart part which seemed to be identical was this one (Casio 91087274212; only 2$ each 12-key stripe): http://www.pacparts.com/part.cfm?sku=91087274212

 

It was very easy to replace the defective stripes (I had two stripes with bad keys): they are not glued or attached in any fashion to anything, they just lay in there. I lifted the bad stripes (grey colored), and put there the good ones (green colored, from PacPart):

 

 

 

 

After that my issue with stuck keys was gone.

 

If I knew what was the culprit in advance, I would have ordered replacement stripes for all the keys, because there is a good chance the rest are also defective which will eventually show. I will probably order the missing replacement stripes for the future, and if the problem returns I will replace the rest of them.

 

Dust couldn't possibly be the culprit here: the placement of the contact stripes is such (under double boards, and most importantly - with the contact pads facing down) that it is extremely unlikely for the dust to get there. (I am sure this is by design.) So my prior attempts to fix the issue using canned air were obviously doomed.

 

It's been one month since I fixed the piano, it was heavily used by me and my three kids, and everything seems to be perfectly fine.

 

I just tried to blow air from an air can around one of the bad keys, no improvement. So no easy fix for me.

 

I've ordered a few contact strips from the link above, and will be disassembling the piano again when I receive them.

Thanks - I only tried with a hair drier, pointed right at the contact strip (with the keyboard partially disassembled)  - obviously not as strong flow as with an air can, and it didn't make any difference. I probably should try an air can.

Recently (~1 year ago) my fairly new PX-135 developed a nasty problem with a few keys (random: not the same octave, not next to each other). Specifically, if one hits one of these keys harder than a certain amount, it gets "stuck" at the highest volume (so touch response no longer works). The "fix" I found is to hit it even harder a few times in a row, and then it's back to "normal". This is not a purely electric issue - if I turn the piano off, wait, and turn it back on, the issue is still there. From the research I've done it looks like the culprit are the rubber contacts responsible for the velocity measurement (touch response). Because this is a recurrent issue, perhaps this is as simple as some dirt getting inside the contact and moving back and forth there, depending on how hard the key is hit.

 

I tried to get to the bottom of this by disassembling the piano. Unfortunately the keyboard  design is really bad: it looks like the only way to get to even one of these rubber contacts one has to remove one by one all the 88 keys, which is tricky. I tried, and removed some, but then accidently broke a part of a black key support, so it became wobbly (but still works), at which point I decided to stop, especially because I didn't have any replacement rubber pads.

 

I think I will attempt a disassembly one more time, because the problem drives me and especially my kids (who are learning to play piano) nuts, but this time I want to have some spare rubber contacts in case I need to replace some. I did find this spare parts store which apparently has some contacts for PX135:

 

http://www.pacparts.com/library/model.cfm?mfg=Casio&model_id=PX135WE&action=list_part&back=0

 

Does anyone know which of these are for velocity measurement? Also, can I buy somewhere the conductive paste/powder used inside the contacts (is it possible to replace it?) For exazmple, how about this repair kit:

 

http://www.oaktreevintage.com/parts/keyboard/casio_key_contact_repair_re-coat-kit.htm

 

Any other advice?

 

Thank you!