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!


  1. Now this is something which is beyond my understanding, I need to know basics first to get this blog. Going to show it to my friend to get more understanding of it, thanks for sharing it

  2. Yes it could be worst if your keyboard gets stuck right at the time of performance. But i appreciate your efforts to be offered freely to help them and you fixed it finally.