Keybord not working

[Sekvanod]

ok i first i'll describe the problem and than the story:                                              sory for my english im not a native speaker (if something is written badly plese say it in comments                                                                                                                                                                                                               and i will try to explain)

 

MC-800M vulcano MODECOM

the keybord has power to ti (the lights light up and the numlock glows (iif i have 2 keybords pluged in and turn on caps it lights up as well))

so the problem is that when i turn on on screen keybord and smash all the buttons only the [SHIFT] [CTRL] [ALT] show up as presst.

 

i've tried to plug it in from usb 2.0, 3,0 and ps2 via adapter

 

annd yeh it was working at first an this hapend before but i just restarted the pc and than it worked (last time it hapend i needet to restart a cuple of times but than it worked for a wile)

 

the couse may be that taht it was sticky when i got it (used) an i took it apart and cleand it theraly and i dit let it out to dry (it was working fine after for a couple weeks but than the first time it stopt working i restart the pc and it worked)

 

if any one has any ideas what culd it be ples tell me