So I got a Kaypro 16/2 computer and it boots up to DOS just fine, but the keyboard does nothing. I always get a "check keyboard" message. At first I thought it was the keyboard itself, but now I know that there is something wrong with the keyboard logic on the processor board. It is either that 1. the 74LS322 chip is bad, and that I can buy a replacement or 2. a tantalum capacitor is bad. The capacitors in question are 640 picofarads, which are a weird size and I cant find replacements anywhere. My question is, could I use a 620 or 650pf capacitor instead, or is there another solution?
I found a schematic of the 16/2 which I've attached below.
Any help would be greatly appreciated!