ciao a tutti,
I'm about to restore a CA501 recently purchased.
The module is working, but the front panel is missing.
I have found a nos front panel which I'm about to receive in the next days.
I started to clean the module, since the keyboard was not responsive at all.
Differently form other CA from Casio, the keyboard is a multiplexed sistem,
like in some of the calculators.
The pressure of a key, cause the underlying structure to generate a single
combination of contacts that thru a zebra strip will go to the module.
As a matter of fact, passing the zebra with a tweezer, gently, will make
the module behave like the keys were pressed.
At first, I have cleaned the zebra with cotton and alchool and some of the keys
began to work.
As it can be seen in the pictures, the keyboard is made of several pieces.
We have the rubber keys, just mechanical action, no electrical conduction.
The yellow strip, adhesive, that is the first thing that goes into the case
against the keys (from the inside). The the white one, the side with the continuos
strips will go toward the adhesive layer and the keys, and represent the row
contacts.
Then the trasparent layer, double side, than the zebra and the module.
When I have cleaned the transparent plastic layer a lot of dirty came away,
but I'm worried that it was more graphite, than dirt. Does anyone has done this before ?
Now, I can only get the keyboard to work if I put the two layers directly
on the module but out of the case, looks like when the keyboard is in place
again, the zebra is not pressed against.
Anyone has a suggestion ? Can I keep cleaning the layers ?
Thanks again for help, Alberto
I'm about to restore a CA501 recently purchased.
The module is working, but the front panel is missing.
I have found a nos front panel which I'm about to receive in the next days.
I started to clean the module, since the keyboard was not responsive at all.
Differently form other CA from Casio, the keyboard is a multiplexed sistem,
like in some of the calculators.
The pressure of a key, cause the underlying structure to generate a single
combination of contacts that thru a zebra strip will go to the module.
As a matter of fact, passing the zebra with a tweezer, gently, will make
the module behave like the keys were pressed.
At first, I have cleaned the zebra with cotton and alchool and some of the keys
began to work.
IMG01660.jpg
IMG01661.jpg
IMG01662.jpg
As it can be seen in the pictures, the keyboard is made of several pieces.
We have the rubber keys, just mechanical action, no electrical conduction.
The yellow strip, adhesive, that is the first thing that goes into the case
against the keys (from the inside). The the white one, the side with the continuos
strips will go toward the adhesive layer and the keys, and represent the row
contacts.
Then the trasparent layer, double side, than the zebra and the module.
When I have cleaned the transparent plastic layer a lot of dirty came away,
but I'm worried that it was more graphite, than dirt. Does anyone has done this before ?
Now, I can only get the keyboard to work if I put the two layers directly
on the module but out of the case, looks like when the keyboard is in place
again, the zebra is not pressed against.
Anyone has a suggestion ? Can I keep cleaning the layers ?
Thanks again for help, Alberto
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Alberto Fenini
alberto.fenini@consys.it
alberto.fenini@consys.it