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Re: Crumar T1 repair

2007-06-20 by Daniel Desy

Les,

I finally got around to trying guitar string to solve my keyboard
problem, and it did indeed work!  Thanks again!

Dan

--- In crumar@yahoogroups.com, Les Bampton <albion_sp@...> wrote:
>
> Hi Dan,
> 
> Pleased you found my tips useful even though they are probably a bit
unconventional, any purist would probably be quite shocked, but in the
case of my Stratus, a complete change of keyboard was the best option.
> 
> If you want to change the keyboard on your T1 the first thing you
will need is a donor keyboard. The best source for these is cheap
electronic keyboards that kids learn to play on, like Casio's ect. You
can buy them really cheap on ebay. The easiest to convert are said to
be Casio's, but I used a Yamaha in mine partly because I just happened
to have a spare one, and partly for quality. Your donor keyboard will
probably be from a digital keyboard which means that on the keyboard
PCB will be lots of Diodes, these all need to be removed. Now you will
need to work out the wiring, for the keyboard, each key needs two
connections, one side for the individual wires to each key, and the
other side for a common contact to all of the keys. On my Yamaha
keyboard it was easy to work out where the individual wires had to go,
but on the common side I had to trace several contact points and join
them all together to make one common point for the single common wire.
You should now be able
>  to wire your donor keyboard like the original keyboard.
> 
> To fit the donor keyboard you will need to do a bit of engineering.
First remove the plastic parts from T1's metal keyboard chassis (drill
out the rivets). Now you will need to cut away part of the chassis to
fit the donor keyboard into or it will not fit. You may also have to
modify the donor keyboard to remove unwanted bits that get in the way,
but leave enough extra on the donor keyboard so that you can bolt it
to the chassis. On the Stratus there are circuit boards under the
keyboard chassis and I assume the T1 will be the same. you need to be
very careful that your donor keyboard does not short out the circuit
boards. If this is a possible problem you will need to insulate the
circuit boards from the keyboard and chassis with a none conducting
material like wood, cardboard or plastic. I can't give you exact
instructions of course as yours will be different to mine, but at
least should should now have an idea of what is involved.
> 
> Pleased note that I am trained in both engineering and electronics,
so for me it was not to difficult to work out what to do. I suggest
that unless you are confident in your engineering and electronics
skills, then you just replace the springs with bits of guitar string
as that should be fairly easy to do. But if you replace the keyboard
with a donor keyboard then be very careful and double check all of
your measurements and everything else.
> 
> Good luck and best wishes ..... Les
>

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