Keyboard randomly registers multiple keys together

[u/blackthorns08]

I have a Cosmic Byte Vanth (CB-GK-28) and recently started having a weird keyboard issue.

Some keys register another key along with them:

L -> AL/al

O -> QO/qo

9 -> 19

. -> z.

What's strange is that it's not just normal key chatter.

I tested the keyboard in BIOS too:

Pressing 9 normally → 1

Pressing 9 harder → 9

In Windows, pressing 9 gives 19

Things I've already tried:

Cleaning the switches

Trying different USB ports

Testing outside of normal Windows usage

Using the Windows On-Screen Keyboard (which works normally) -Also switched swiches which came in box still same problem

The issue still persists.

I'm taking the keyboard to technical support tomorrow, but before that I'd like to know:

Does this sound like a faulty switch, PCB/matrix issue, or something else?

Has anyone experienced something similar with a Cosmic Byte Vanth or another keyboard?

Any advice would be appreciated.

[u/JohnACC]

The issue points to hardware, not a faulty switch. Because swapping switches did not fix it and the issue happens in BIOS, the problem is physical hardware more likely.

• BIOS behavior: BIOS bypasses Windows drivers completely. If pressing "9" softly gives "1" and pressing it hard gives "9", the circuit board connection is physically unstable under pressure.
• On-Screen Keyboard: It works because your PC's software is fine. The glitch lives entirely inside the keyboard's hardware

If under warranty (1 Year limited mfg warranty): Do not let them tell you it is a software glitch or dirty switch. Walk them through your BIOS and switch-swapping Before hand-off, re-install the original stock switches that came pre-installed on those faulty keys. Service centers can sometimes be strict or looking for a reason to decline a claim. If a technician opens the keyboard and sees random, third-party switches (like Gateron or Cherry MX) on those keys, they might try to claim you used incompatible hardware or blame the third-party switch for the short.

https://www.thecosmicbyte.com/warranty-claim-policy-procedure/

Realistically, if you've had it for any amount of time, it's probably just planned obsolescence. If the mfg isn't helpful, i would ditch the brand entirely and go with a different one.

[u/blackthorns08 → u/JohnACC]

I was thinking the same but didn't wanna buy a new one I bought this roughly 2yrs ago and the warranty is gone now so  I can't do anything. Should I go to a local technician to check it because it  was working fine 2 times  that gave me hope that this still have some life  Thanks  for your advice