Weird LED Problem for Filco MJ1

[cgbuen]

I recently picked up a cheap "as is" Filco MJ1, whose owner said was having trouble getting it to work over USB. Upon receiving it, it seemed to work fine.. until I noticed something weird - if I pressed Caps Lock or Scroll Lock several times quickly, there was a decent chance of the keyboard turning off completely, until I used another keyboard to press the respective Lock key again to "free up" the original one.. it was a pretty odd situation.

The warranty seal was already broken, so I opened it up, but didn't see anything really glaringly wrong with the soldering or the traces, and on contacting the seller he said the same exact thing - that he had opened it and didn't see anything wrong either. I did manage to do something that helped alleviate that issue, which was to re-seat the USB connector and the controller - this stopped the keyboard "turning off" issue.

However, it still has a different (less annoying) issue of the LEDs at times not being able to "catch up." That is, if I hit Caps Lock or Scroll Lock several times quickly now, the keyboard doesn't turn off anymore, but every 10 fast presses or so, either the LED won't turn off even when the Lock is off, or it won't turn on if the Lock is on. Another two presses or so gets it back on track.

Anyone have any thoughts on what the issue might be? Other notes..

- Other keyboards that are plugged in always show on or off correctly, no matter how fast or how many times I press the button, and no matter which keyboard I press it on. Only this MJ1 has the LED problem.
- I've been able to replicate this on two different machines.
- The LEDs aren't dim or anything.. so I don't know if the LEDs themselves are bad or something.
- The thing that the USB connector connects to (the thing connected to the PCB.. "mount shrouded header"? Is that what that's called?) was dirty only on the top when I first opened it up - probably not an issue at all but just want to point that out.

[elitekeyboards]

This was a rather funky issue with MJ1 Full size and Tenkeyless board controllers. The problem is difficult to diagnose since it is intermittent, but it's usually drawn out of the shadows by pressing the Caps or Scroll lock repeatedly, wherein a delay will occur in the LED changing. Diatec was told by the factory that it was likely some kind of controller firmware corruption and we were never informed that they were able to pinpoint the issue so I don't know if it was every solved definitively, but the occurrence of it did taper off after a while.

Long story short, unless your keyboard is a Tenkeyless or a late model full size (which is a MJ2 in disguise) then there is no way to replace the controller and you've got a lemon:(

You mention re-seating the controller, but don't mention which board you have; if you have a Tenkeyless, then the HID Liberation Device might be the fix...though I can't vouch for how stable this controller is; haven't tested it.

If you have a full size board, then you're going to have find someone willing to sell you a new controller, as it is different from the Tenkeyless controller.

[cgbuen]

Oh, nice info.. it's a TKL. I just swapped controllers with an TKL MJ2 that I had, and sure enough, the MJ1 works now and the MJ2 is having issues. I'm on my way to picking up a couple of the bpiphany programmable controllers. Thanks so much!