Commodore Amiga, C128, C64 Mitsumi Key Conductivity Tester Kit

Description

International customers – please read the shipping notice below about shipping options
I was doing some research earlier this year to try and find a way to rejuvenate the conductive rubber on the Mitsumi key stems used in the Amiga/C128 and also the C64. I needed an accurate and repeatable way to test the resistance of the rubber contacts. To that end I came up with a very simple PCB and 3D printed housing that works very well. I now find I use it when cleaning keyboards so I can test the stems before reinstalling them, that way I know the KB will most likely work properly when put back together.
It has one aperture that fits the Amiga/C128 stems and another that fits the C64 stems. This is for the Mitsumi keyboards only.
The PCBs have a ENIG (gold) finish to provide a stable contact surface for measurements.
It is very simple to use. Connect the leads to your ohm meter. Insert the key stem into the correct aperture and press down lightly. Make note of the resistance. The typical resistance is about 200ohms, research has shown that a resistance up to about 1kOhm will work without problems.
In case you are curious it is very easy to rejuvenate the conductive rubber, using common household chemicals, and reduce its resistance back down to a level that will work. I did a video about the process and will put the link below. Sear YouTube for 'Hey Birt!' for the video I did about this process.
International shipping notice – Once again we are seeing slow downs in international shipping services via the mail, i.e. USPS and destination countries postal system. Many parcels are arriving in a normal time frame and some are taking six weeks or more. Judging by the slow mail service in the spring it may take up to 12 weeks to receive your package shipped via the post. Please consult your country’s postal service for up-to-date information about mail delays.