# Conductive ink and diodes needed

**URL:** <https://forums.syntaur.com/t/conductive-ink-and-diodes-needed/6797>\
**Category:** Synth Repair\
**Created:** [February 12, 2024, 3:27am UTC](https://forums.syntaur.com/t/conductive-ink-and-diodes-needed/6797 "2024-02-12T03:27:07Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![Danny](https://forums.syntaur.com/letter_avatar_proxy/v4/letter/d/848f3c/32.png) [@Danny](https://forums.syntaur.com/u/Danny)\
**Post date:** [February 12, 2024, 3:27am UTC](https://forums.syntaur.com/t/conductive-ink-and-diodes-needed/6797/1 "2024-02-12T03:27:07Z")

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In my intent to fix the px100 Casio (cat perded on it) the circuits got rusted and as I tried to fix it I washed away the printed key sensor and the back shows 2 diodes are rusted and one fell off. The problem is that I’m in Cambodia and I had to do my own diy graphene from several battery rods but this is m question, what is the code for the diodes under the touch panel where the key come is contact with. As you can margine buying it for $64 would be easy but I’m on the other side of the globe and post here s not reliable.?Is there a kind soul able to lend a hand with information? Thanks  
I will try to get the diodes here.

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**Author:** ![wernersaurus](https://forums.syntaur.com/user_avatar/forums.syntaur.com/wernersaurus/32/1085_2.png) [@wernersaurus](https://forums.syntaur.com/u/wernersaurus)\
**Post date:** [February 13, 2024, 11:21am UTC](https://forums.syntaur.com/t/conductive-ink-and-diodes-needed/6797/2 "2024-02-13T11:21:50Z")

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They’re 1N4148 - should be easy to get

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**Author:** ![Oleg](https://forums.syntaur.com/letter_avatar_proxy/v4/letter/o/ebca7d/32.png) [@Oleg](https://forums.syntaur.com/u/Oleg)\
**Post date:** [February 23, 2024, 11:19am UTC](https://forums.syntaur.com/t/conductive-ink-and-diodes-needed/6797/3 "2024-02-23T11:19:56Z")

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Any common silicon diode should work there. It’s a digital key scanner circuit; it’s not really sensitive to particular diode part number  
Just make sure you install it with correct orientation

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**Author:** ![wernersaurus](https://forums.syntaur.com/user_avatar/forums.syntaur.com/wernersaurus/32/1085_2.png) [@wernersaurus](https://forums.syntaur.com/u/wernersaurus)\
**Post date:** [February 24, 2024, 12:16am UTC](https://forums.syntaur.com/t/conductive-ink-and-diodes-needed/6797/4 "2024-02-24T00:16:07Z")

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There is a paste available to “reconstruct” worn or bad carbon contacts but that only works if some original material is still present. Your problem will be that the contact interface between the carbon and the copper track may have separated. I have never been able to reliably re-create that.  
As an aside - that paste is very expensive too - about same as a new board or even more