Keyboards starts spamming many letters after soldering

[Naweo]

Hey guys!

I finished building a board, but when I plug it in it does some really crazy things.

As soon press a button, it starts opening chrome indefinitely, and I assume it like presses "C / Enter" and other buttons/keystrokes simultaenously.

Here are pictures of board:









Please note that I soldered in 3 LEDS for numlock, scrolllock and caps lock. The rest of the LEDS I did not solder in.

I may have screwed up the polarity of my LEDS, but that should not cause this keyboard issue I believe?

The two green arrows point at two solder joints that may be too tall.

I also identified solder joints that did not contact the entire pad and may have had a small hole.

What do you think could cause such an issue? How should I proceed to resolve this?

Thank you!

[Naweo]

Any help would be very appreciated!

[suicidal_orange]

It's not the LEDs - either they glow or they don't but that's as bad as they get.

Did you solder the diodes?  If they are the wrong way round you could get some random output.

Did you put it back in the case to test?  Any chance the cable was shorting on a switch?  That would do it too...

If no to the above it would be helpful to know exactly which keys get pressed - how many?  Are they all in a row/ column(s)?  A Switch Hitter screenshot would be good.

[Naweo]

It's not the LEDs - either they glow or they don't but that's as bad as they get.

Did you solder the diodes?  If they are the wrong way round you could get some random output.

Did you put it back in the case to test?  Any chance the cable was shorting on a switch?  That would do it too...

If no to the above it would be helpful to know exactly which keys get pressed - how many?  Are they all in a row/ column(s)?  A Switch Hitter screenshot would be good.

Thank you for responding,

I did not solder the diodes - it is a stock keycool 84 board. I only changed the switches and removed the LEDS.

As far as I could tell I did not screw up any diodes, but I am willing to do 20x 1080p pictures of all the board if U would be willing to investigate.

I will attempt to give you the switch hitter information as we speak, currently I can tell you the keys pressed and the pattern in word is like:

"       R        R         R      E      R      ^         ^         ^         ^          R           ^           E           ^             E          ^             E              ^             E" like that like 50 times a second.

I want you to note that I changed the cast bottom from Keycool standard to MK84, would the cord from MK84 possibly screw up my PCB? Not really, right?

I am not at all sure if the cable was shorting, I honestly just put the cable back in the case. Do I need to put it somewhere specifically?

Anyway, I will edit this as soon as I know more.

EDIT:

I pressed F, which it registered normally. But as soon as I did that, it pressed and held down all these keys simultaenously:



All of theese keys except for f3 and P.

I dont even know how it is still pressed numpad 4 5 and 6, my keyboard doesnt even have a numpad...

84/87 layout:

[suicidal_orange]

The only problem with swapping case is if it's metal and shorts, either because there's a mounting hole near a diode or it's not tall enough.

With the cable if the case is tight you need to route it round the switches - if it was shorting you would see a dent/hole in the shielding depending what type of cable it is so if it looks perfect that's not it.

Your output has a lot of spaces and looks like shift is held too - that is rather random!

[Naweo]

The only problem with swapping case is if it's metal and shorts, either because there's a mounting hole near a diode or it's not tall enough.

With the cable if the case is tight you need to route it round the switches - if it was shorting you would see a dent/hole in the shielding depending what type of cable it is so if it looks perfect that's not it.

Your output has a lot of spaces and looks like shift is held too - that is rather random!

The thing is, the rest/bottom case is exactly the same as the one the PCB is desgined to use, it even says "keycool" engraved to it in the bottom, so I would suspect it is an exact copy, and it is made of plastic.

I am not sure if the cable looks perfect hehe, not sure exactly what you mean, I am stupid!

But I tried to reroute it around the switches, and it does not touch space yet space is pressed, so I am not sure. All other keys seems to work just fine even when these mass amounts of keys are pressed. The keyboard is 6key rollover as well btw so its strange it can do this many.

[zombiegristle]

Hard to tell from the pics and I have no idea if this would contribute to your symptoms, but it looks like you may have some shorted diode connections? The diode pads between R70/R71 and the ones between R73/R74 look like they have solder bridging them. Also, at the far-right edge of one pic it looks like you might also have a short under the CAPS key but it's mostly out-of-frame so iunno, and I'd also check the connections under R-SHIFT, there are a lot of small components nearby and it looks like the soldering for the switch may be bridging some stuff.

[suicidal_orange]

That pattern looked like my Ducky matrix and I've just had a look - that pattern of keys (even the invisible numberpad) is identical to one of the blocks.   This is too much of a coincidence so they surely share an OEM.

You have a short either on one of those keys (on the leg that's not attached to the diode) or perhaps on the controller?  Looks like there could be one bottom right as pictured but not sure from the angle.

Where did you solder LEDs, in switch (I'm looking at caps lock...) or elsewhere?

[Naweo]

Hey guys, thanks for responding, I will upload additional pictures of suspected switches in one second









I soldered in LEDs for scroll / numlock and caps. Random polarity. When I plug in keyboard, scroll lock and numlock lights up briefly so I suspect they work.

Could they interfere with the system?

I am not sure how I can put the PCB+plate better onto the case, I really try my best to make sure it fits correctly.

Lemme know if you need better quality pictures of something else!

[Naweo]

Additional Picture of F3, F7, Caps, Shift, Alt, T, Y













Note that you might find some solder on some LED pins holes that arent caps/scrolllock/numlock, thats cuz I used solder for heat to pull the LEDS out.

[zombiegristle]

Okay, I definitely see bridged connections on "]}" and the pads by R6, as well as between R73/R74 and over on Q5.

[Naweo]

Okay, I definitely see bridged connections on "]}" and the pads by R6, as well as between R73/R74 and over on Q5.

Are you refering to the LED holes? Would this cause the problems?

[zombiegristle]

Yes, the diode holes that are close together. I don't know if they'd cause your issues but it seems reasonable, since a short would allow flow both ways but a diode only allows it one-way. I know a short-circuit is definitely not going to make things BETTER though, so you should fix them.

[suicidal_orange]

Is left shift shorted to the LED pad?  The pic is a bit dark in the crucial spot...

[Naweo]

Is left shift shorted to the LED pad?  The pic is a bit dark in the crucial spot...

Yeah I would say it is like, not between the LED pads on l shift but the opposite switch solder holes.

If you guys are sure this would cause my issues then I will try to resolve it asap, what would u think is teh best method? Just add solder and pump?

[suicidal_orange]

Is left shift shorted to the LED pad?  The pic is a bit dark in the crucial spot...

Yeah I would say it is like, not between the LED pads on l shift but the opposite switch solder holes.

If you guys are sure this would cause my issues then I will try to resolve it asap, what would u think is teh best method? Just add solder and pump?

That would definitely cause what you're seeing - suck the solder off and see if the random stops, then carefully resolder.

The other shorts between the pairs of LED pads may have damaged the controller so best to clean them too, but they won't cause random keypresses.  Good eyes zombie!

[Naweo]

Is left shift shorted to the LED pad?  The pic is a bit dark in the crucial spot...

Yeah I would say it is like, not between the LED pads on l shift but the opposite switch solder holes.

If you guys are sure this would cause my issues then I will try to resolve it asap, what would u think is teh best method? Just add solder and pump?

That would definitely cause what you're seeing - suck the solder off and see if the random stops, then carefully resolder.

The other shorts between the pairs of LED pads may have damaged the controller so best to clean them too, but they won't cause random keypresses.  Good eyes zombie!

Damn, keyboard works!

Thanks guys!

The only problem is that capslock does not seem to work, but that should be a minor fix I hope

[suicidal_orange]

Glad to hear it, enjoy the new switches

[Naweo]

Glad to hear it, enjoy the new switches

Thanks a lot man,

I tried to resolder the capslock LED,  and now that works as far as I can tell.

The only problem is that I cannot get the capslock switch to work. I will try to upload my job picture now, see if there is a short or if I broke the switch:



Pad not fully soldered, is that important?

[zombiegristle]

Hmmm, it looks a little "iffy". Maybe a cold joint causing too much resistance and preventing it from working. I'd say desolder that one and clean it up a little, and redo.

[suicidal_orange]

Whole pad is better but not required.  The last pic made me realise I wasn't even looking in the right place last time - I was looking at this partially soldered pad )

This is a friendly bit of board where you can see everything, looks like a cut across the trace above D102 but as tab works I'll guess your caps key isn't connected to S on the bottom pins or the little trace from the switch down to D102 isn't connected - your multimeter can confirm.

[Naweo]

Hmmm, it looks a little "iffy". Maybe a cold joint causing too much resistance and preventing it from working. I'd say desolder that one and clean it up a little, and redo.

Heya, yeah...

I tried desoldering and soldering 4 or 5 times now, I am really not sure how I should do this. I try to do it as carefully as I did every other switch, perhaps I just have to replace the switch?

So for safety I should solder all the LED holes together even, also for microscopic better performance?

I am not sure which trace, any chance U could pinpoint?

I do not have a multimeter so I guess I have to be lucky ;P

[zombiegristle]

If you don't have a switch tester but you DO have a spare switch, may as well. It's not going to make it not-work-worse.

[Naweo]

If you don't have a switch tester but you DO have a spare switch, may as well. It's not going to make it not-work-worse.

Changing the switch worked!

I put in the LED with wrong polarity but w/e, in some situations it might actually be annoying.

Please let me  know if there are important things I should do, like if the keyboard gets artificial delay cuz I didnt solder the LED holes or something. Otherwise I guess I am done!

Thanks guys!!

[zombiegristle]

Awesome, congrats and enjoy!

[ander]

Ha ha, "spamming". As a language person, I admire your extension of the term to cover all unsolicited text.