Hi Vogons Community,

I am relatively new to retro computing and I apologize if this post is misplaced. I have a 1989 286 HP Vectra ES/12 which throws an 0352 Keyboard Interface not Functional error on startup preceded by four long beeps. Other documentation shows this error as "Keyboard Error or not connected". I am using a HP PS/2 keyboard with a PS/2 to AT adapter.

Scoping the keyboard port shows a permanent 1.3 kHz square wave on the clock pin from the computer. On startup the data pin pulls high briefly and then drops low. 5V is present on the VCC pin. The motherboard is clean and I was not able to find any broken traces, solder joints or obvious issues.

The system has no hard drive and I don't have a 5.25 boot disk so this is as far as I got. I can't find a schematic for the motherboard online. The CMOS battery is a 6V lithium battery and is pretty dead at this point.

I have a scope and probes and can do mild board debugging but have no clue where to start at this point without documentation or further expertise. Could anyone point me to further documentation or does anyone have any advice how to further debug this issue?

Thank you for your help