keyboard not work!!

[yangyan12]

I just received a pearl 2000, the problem the keyboard don't work! The desk can
boot up properly and the LCD display properly but the keyboard and softbutton ,
functiong button , fixture attributes buttons all don't work. But the preset
button and faders works well . It seems the chip used to control the keyboard failed
isn't it? So would you mind tell me which chip used to control the keyboard is it
the chip DN74LS374N on pcb PP-1201-5995A?