CM QFR (w/ Frosty Flake) glitching out?

[MidnightXZ]

So I've been using a QFR with a Frosty Flake v2 for the last month or so and it's been working out beautifully. However, I only just got home today, and it started glitching out like crazy as I was typing, such as endlessly typing the same set of random letters over and over. Normally, you would say that I had a broken layout file. However I was using a relatively unmodified layout generated by metalliqaz's Easy AVR Keymapper, changing the default only by adding in media keys to the Fn layer. After a bit of experimenting, I realized that when I was able to get the keyboard in a somewhat working state, it would send almost every key perfectly fine, except the keys Q,W,E,R and U,I,O,P were unresponsive in Aqua's Key Test. In another case, those keys and the rest would be working perfectly, but when I held down the 'I' key and any combination of I and the 'K'  ', <' '8*' keys, Aqua's Key Test would light up almost all the keys on the row of what I would be pressing along with a few other random keys.

<- Pressing I and '8*'
<- Pressing I and ',<'
<- Pressing I and K
<- Pressing all four keys in the above screenshot.

Of course I tried putting the original controller back on, and it ended up glitching in other ways as well. Notably, where it would start hitting keys that wouldn't even exist on a TKL, such as numpad keys.

The weirdest thing that I noticed was when I removed the keyboard from the case (removing the top and bottom, and unscrewing the daughter board for the USB connector off and letting it flop around and attempted to type with the PCB/Plate/Keys/etc, it started functioning perfectly fine! None of the problems I stated above occurred. However, once I put it all back together, the exact same issues above came right back!

I'm rather stumped by this. My keyboard was working perfectly fine for the last month and when I last used it the night before in a gaming session, and yet when I come home the next day it has these weird issues which is severely affecting its functionality. Would anyone possibly have any idea as to what could be wrong with my QFR, because I haven't the slightest clue.

[tp4tissue]

board shorting out some where

or the PCB is flexed / cracked somewhere

[MidnightXZ]

I had a feeling it was possibly shorting somewhere. How would I be able to check if the board is shorting out somewhere? I don't have much in terms of tools and I have a lot to learn about electronics and stuff. I wonder how the PCB would be damaged like that if it's mounted onto a plate. The PCB is rather gross though, covered in what I think is flux all over. Although the keyboard has been working perfectly the whole time until just tonight when I got home.

EDIT: Also, that doesn't explain why the keyboard starts working perfectly fine again when I remove it from the case.

[tp4tissue]

I had a feeling it was possibly shorting somewhere. How would I be able to check if the board is shorting out somewhere? I don't have much in terms of tools and I have a lot to learn about electronics and stuff. I wonder how the PCB would be damaged like that if it's mounted onto a plate. The PCB is rather gross though, covered in what I think is flux all over. Although the keyboard has been working perfectly the whole time until just tonight when I got home.

EDIT: Also, that doesn't explain why the keyboard starts working perfectly fine again when I remove it from the case.

if the pcb has a crack

once it's stressed in the case, one of the main traces is not connected as the board is flexed..

if it's not a trace, then it may be a cold joint near the controller.

but outside of the case, the flex goes away, and the board is fine..

the plate isn't always straight either.. sometimes the plate warping due to cold weather can actually crack the pcb..

[MidnightXZ]

I had a feeling it was possibly shorting somewhere. How would I be able to check if the board is shorting out somewhere? I don't have much in terms of tools and I have a lot to learn about electronics and stuff. I wonder how the PCB would be damaged like that if it's mounted onto a plate. The PCB is rather gross though, covered in what I think is flux all over. Although the keyboard has been working perfectly the whole time until just tonight when I got home.

EDIT: Also, that doesn't explain why the keyboard starts working perfectly fine again when I remove it from the case.

if the pcb has a crack

once it's stressed in the case, one of the main traces is not connected as the board is flexed..

if it's not a trace, then it may be a cold joint near the controller.

but outside of the case, the flex goes away, and the board is fine..

the plate isn't always straight either.. sometimes the plate warping due to cold weather can actually crack the pcb..

From what I can tell, the PCB doesn't look damaged in any way. No cracks, no forms of stress anywhere. I can't imagine how the PCB how the PCB would be stressed or flexed when its inside the case. The standoffs and the plate prevent the PCB from flexing, does it not? The keyboard is left in a room with central heating, where the ambient temperature of the room should be the same constantly. I personally can't see anything wrong with the board or how it would have gotten damaged overnight with nobody touching it. I also can't understand why it works perfectly fine outside of the case, or how the case is affecting it either since there is only one screw holding the whole keyboard together so there isn't exactly a lot of stress on the keyboard in general.

I could just be acting completely ignorant about the issues you're pointing out though because I looked at it and believe its fine as it was working the very last time I used it and nobody has touched it.

Bad Potato pic:


EDIT: Okay I think I have discovered what is causing the keyboard to freak out why it works perfectly fine when it's outside of the case. When the keyboard is in the case and everything, typing on it hard causes the plate and pcb to flex very slightly downwards and touch the daughter board for the detachable USB cable connector. This seems to short out the pcb as the daughter board is basically under the I key so I guess its shorting out that column of the matrix? Anyways, when the keyboard and daughterboard is removed from the case, everything works perfectly fine. When it's back in the case and I type very lightly, to the point where I'm not bottoming out on this MX Red board, it works fine as I'm not flexing the keyboard to make contact with the daughter board. When I start pressing down on the keyboard to flex it to make contact, all the issues listed in the OP appear. Without flexing the keyboard to where it's touching the daughter board, everything works all fine and dandy.

Tl;dr: Somehow my keyboard starting making contact with the daughter board for the detachable USB cable connector and it's shorting out the PCB, specifically the 8IKM column of the matrix and I presume that is what is causing all the symptoms listed in the OP.

No idea why it started happening overnight but at least I know why now. Guess I need to replace that daughterboard with a cable or something.

[Dreamre]

Try putting some electrical tape/drawer liner to prevent it from shorting. I had a Ducky Shine 2 with it shorting with little pressure. It was fixed with some electrical tape inside the case.

[MidnightXZ]

Try putting some electrical tape/drawer liner to prevent it from shorting. I had a Ducky Shine 2 with it shorting with little pressure. It was fixed with some electrical tape inside the case.

That sounds like a good solution as well, I'll try it. Thanks!

[rowdy]

This is a QFR, right?

Some of those were a bit flaky if the case was tightened too much.

You might try not quite tightening the screws all the way - it might help too.

[MidnightXZ]

This is a QFR, right?

Some of those were a bit flaky if the case was tightened too much.

You might try not quite tightening the screws all the way - it might help too.

The problem occurred before even getting screwed on. But yeah, I found the problem already. Thank you though.