VZ1 Audio and keys

[rixupi]

Hi all.

I have 2 casio synths in my collection. A VZ1 and a CZ101. The VZ was second hand and the CZ I bought brand new a long time ago. I have 3 problems with the VZ -
1. The display has a fault on one of the lines.
2. The Line Out L and R are intermittent, quiet and crackly at best
3. The rubber key contacts are shot.

Number 1 is no major problem, but the other two are.

I`m a fairly amatuer electronics person but I know my way around enough to fix certain problems, but my guess is that with 2, maybe the op amps have a problem, but the headphone outputs are fine, which is how its connected at the moment.
Number 3 is real pain as I cant use the keys, and I have to use it as a glorified rack unit, and I`d like to be able to use it as a controller keyboard, rather than using my Roland piano. I have cleaned the pads and circuit boards at least 3 times, all to no avail.

Hopefully some of you out there can suggest a fix for the last two

[IanB]

Number 2 might well just be poor contact in the connectors. Easiest way to check this would be to open it up and tap a signal direct off their connections to the PCB and see (er, hear) how that sounds. When op amps fail, they usually fail completely. It's also possible the circuit board is cracked by the connectors- inspect closely with a magnifying glass with a light source arranged to cast shadows.

 

As to the contacts, I'm not familiar with the mechanics of this device, but is the rubber still springy and in good condition?

[Chas]

In addition to what IanB said above, with regards to Number 2, I'm not sure if the VZ-1 has the output relays as per the CZ series, but if it does, the symptoms you describe is exactly the same as when the play up in the CZs. See video below of what you can do to rectify the issue. Though obviously, if the VZ doesn't use output relays then this won't apply.

 

Concerning Number 3, do any of the keys work or is it just a few? IIRC, they use  springy silicone domes with carbon pads, and if these carbon pads wear, or get cleaned too vigorously, they can lose some of the carbon and also conductivity. I had this issue on a 1980 CT201 that had some barely functioning/ dead keys at the upper end. Before I bought it, it looked like something had been spilt and got between the keys and the circuit traces. I cleaned it up as best I could, but I might have been a little over zealous with cleaning the carbon pads as they sort of worked after cleaning, but then stopped working again. I managed to resurrect them by taking the keyboard apart once more, and this time I applied a carbon pencil over the pads to try and replace the suspected lost conductivity. Amazingly, it did the trick and continues to work months later, even though what I've read suggests that the carbon pencil trick is likely not a permanent fix.

 

If it's just a few random keys that aren't behaving, then maybe try the above. If the whole keyboard is not responding, then that likely suggests an issue between the keyboard and circuit connectors.

 

 

 

[IanB]

Further to Chas's comment, I just found the VZ1 service manual and it does indeed have the output relay as he suggested. A likely culprit!

[pianokeyjoe]

For the key contacts you may need to contact syntaur dot com for parts. The rubber contacts are used but known to work from them. Another option which I use alot is EBAY. The cheapest used classic Casio keyboard with touch response you can buy to use for parts for your synth is CPS201, CPS700 or CT6000. Yes I know, these are just as precious but they are NOT synths and if you got lucky and bought more than one of the same model, you can part one out for your VZ1 which is NOT cheap nor readily available for purchase cheap anywhere that I am aware of. The keybed of the VZ1 is the same as the FZ1 but is a semiweighted version of the CT6000 and CPS201 version which they themselves have a light metal weight in those keys. The HT6000 also uses the same keybed with no weights but the same rubber contacts. The CPS2000 and cps700 use piano style keys but again, same contacts as vz1 and the cps80 and cps85 also use the same contacts but piano style keys.. So you have choices but they require either buy it IF the contact is available or cannibalize another precious classic Casio. Ouch..

[CYBERYOGI =CO=Windler]

You can buy on eBay conductive carbon paint. It is normally intended for repairing PCB traces or EMF shielding, but it may also work to fix the black carbon rubber contacts of the keyboard silicone strips.

 

In cheap keyboards where individual contacts of the strip were destroyed/torn, I occasionally cutted out that dome and replaced it with a piece from another keyboard or cheap calculator with similar domes (independent of the contact strip layout). It might also work to glue only the carbon rubber dot of something else on the strip using silicone bathroom sealant or fishtank glue (be very careful not to soil the conductive side). However it may be that for velocity sensitive keys it will feel to uneven.