Saturday, February 27, 2016

Connector Archaeology

Yesterday a local band was having problems with the DC power jack on their main keyboard, a Hammond XK-1c, so I offered to fix it.

It is very odd to leave a bar with a keyboard from the band you just watched, and very uncomfortable to see it in pieces when you know they'll need it the next night.

Back at the makerspace, I extracted broken plastics which jammed the jack and prevented it from powering up. But did I have a replacement jack to fit this odd kind of DC plug?

An EIAJ-04 plug. I was looking for the jack.

The only harvestable jack did not look like it could handle the keyboard's current requirements. I needed to order one but had no idea what type of jack this was. The parts search pages for Digikey and Mouser don't have a column for "looks kind of like a regular DC connector, but isn't".

Looking around the makerspace, I realized that HP, Dell and Sony laptops all use a similar style connector. With that clue, I finally discovered that this is an EIAJ connector. They come in five sizes, so that you can't accidentally plug a higher voltage adapter into a lower voltage device.

The Sony laptop plug, needing 19 volts, appears to be an EIAJ-05 connector, while the Hammond, needing 12 volts, has the same measurements as an EIAJ-04. (The HP's connector looks just like the Sony's but is a little larger. Perhaps an EIAJ knockoff?)

It took a bit more searching to find that CUI and Hosiden make these jacks. Both Mouser and Digikey sell the CUI version, part number PJ-019.

As far as the band was concerned, I got the keyboard returned to them usable for their next show. In a few days the new connector will arrive, and it will be good as new!