The officially official Devuan Forum!

matze72

Member

Registered: 2020-06-02

Posts: 12  

Problem with keyboard: Key presses are sometimes ignored

I have the following problem with my keyboard:

when typing sometime (actually one or two times per line) key presses are ignored.
Especially if I start to type something in firefox, but the problem is not restriced to firefox and happens also with different apps.

The problem does not appear when using the keyboard with my windows laptop (using a kvm switch).
And it also happens with my other keyboard.

Andre4freedom

Member

Registered: 2017-11-15

Posts: 271  

Re: Problem with keyboard: Key presses are sometimes ignored

Have you checked by swapping the connections from your kvm switch to the 2 computers? It may be a flimsy contact or cable.

rolfie

Member

Registered: 2017-11-25

Posts: 1,526  

Re: Problem with keyboard: Key presses are sometimes ignored

That sounds like a typical HW problem. Remove your KVM switch and test.

matze72

Member

Registered: 2020-06-02

Posts: 12  

Re: Problem with keyboard: Key presses are sometimes ignored

Indeed, if I connect the keyboard to the computer the problems disappear.
Thanks

kapqa

Member

Registered: 2019-01-02

Posts: 808  

Re: Problem with keyboard: Key presses are sometimes ignored

have similar issue with kvme with 4 usb ~ on newer devices like risc-v or raspberry tipes it may fail to enter properly the keystroke or miss completely; also i noticed, that not all keyboard are equally ideal for use with with kvm, some seem not supported at atll.
the vendor support said i should switch to anoterh "mode" > sun os/2 or similar, but the keystroke to achieve it are somewhat difficult or elusive, or maybe just did not understand it properly (could also be bit faulty since second hand-warehouse  buy). otherwise, very pleased with the item, just hoped it could offer also ps/2 functionality next to usb ~ but that maybe be considerable more expensive.

edit: just checked with the support podf:

• Sun / Mac keyboard support and emulation*
Firmware upgradable
* 1. PC keyboard combinations emulate Sun / Mac keyboards
2. Sun / Mac keyboards only work with their own computers

Last edited by kapqa (Yesterday 15:07:19)

Ron

Member

Registered: 2018-04-22

Posts: 628  

Re: Problem with keyboard: Key presses are sometimes ignored

What brand KVM switch is it? Mine is StarTech and never had a problem with them (I have a 2-way and a 4-way). I tried a cheap brand once but the looks on the monitor sucked so I returned it.

Last edited by Ron (Yesterday 13:54:47)

blackhole

Member

Registered: 2020-03-16

Posts: 282  

Re: Problem with keyboard: Key presses are sometimes ignored

If the KVM itself is hub powered rather than self powered, then there's a potential problem.

With basic USB KVMs, when you switch it over, it momentarily disconnects, then connects to the other device and proceeds to draw power from that.

Wih those types of devices, neither of the two connected host PCs will detect the KVM, they will simply register the keyboard and mouse connection/disconnection.

If it's only problematic on the one device, that points to either a cable problem or power problem.

As the problem goes away with the KVM out of the picture, you should switch the cables around and see if the problem moves to the other PC - if it does then ypu've found the problem. If it remains with the same computer, despite switching cables, then it's clearly specific to that PC and likely power related.

Last edited by blackhole (Yesterday 18:28:20)