ISA-486SV2 Keyboard interface error

[ZapdoZ]

Hi there!

Whenever i start the computer, the BIOS loads and i always get a Keyboard error message. I tried out different keyboards, different keyboard settings (on the keyboard), different BIOS chips and different Keyboard BIOS chips, but i still always get the Keyboard interface error or just a keyboard error.

What can i do?

Thank you in advance,

ZapdoZ

 

[Stone]

Check for battery leakage and board damage from it.

 

[ZapdoZ]

The battery is leaked and you can see some board damage. images provided

 

[Stone]

That might be the problem. Try checking the traces to the keyboard connector for continuity. If you find one or more that are discontinuous solder a jumper across the discontinuous area(s). See if that helps.

 

[ZapdoZ]

Is it possible to desolder the Battery?

 

[Chuck(G)]

Not only possible, but recommended. If necessary, you can clip the leads at the board--that will make desoldering easier. Look around the board for a 4-pin header (usually missing one pin) for attaching an external battery (after you've got the corroded traces patched). If those are present, you don't even need to remove the clipped-off battery leads.

 

[Unknown_K]

Is the square metal shield on the front of keyboard connector still attached to the motherboard or have the 2 legs broken? You need that ground intact.

 

[modem7]

I have the same motherboard, and used it for the diagram at [here].

Per the diagram, after you have removed the leaking 'internal' battery, and repaired any damage, fit an appropriate 'external' battery to the 'BCON1' connector, and change the 'INT/EXT' jumper to the 'EXT' setting.

For an idea of what can be fitted to the 'BCON1' connector, see the options at [here].


The 'gunk' from the leaking battery can get into all kinds of places, so look carefully. An example photo is at [here].

... but i still always get the Keyboard interface error or just a keyboard error.

I will look for my motherboard and see what the error message is for:
1. Keyboard controller removed (simulating non-responsive keyboard controller, or its poor connection to motherboard); and
2. No keyboard (kind of simulating broken traces, etc. in the path from controller to keyboard socket)

Because different BIOS' can give different error messages/codes, I will also provide details of the particular BIOS fitted to my motherboard.

 

[modem7]

I will look for my motherboard and see ...

I cannot find the motherboard.

 

[ZapdoZ]

Thank you all so much!

I found three broken traces and set a jumper to replace all of them.

Now I can finally get into the system BIOS and the keyboard errors is gone!

 

[keenerb]

Thank you all so much!

I found three broken traces and set a jumper to replace all of them.

Now I can finally get into the system BIOS and the keyboard errors is gone!

View attachment 50683

Those early BIOS color schemes were god-awful. What were they thinking?

 

[retro-pc_user]

Worse than the AMI WinBIOS. The WinBIOS was actually pretty good since it'll allow the user to use the mouse to navigate, and they ended up going back to the keyboard-only navigation BIOS. A lot of people didn't like the AMI WinBIOS at all, which I understand.

Better to have AMI for the BIOS over Award (I had a board that suffered miserably and the BIOS had the infamous Y2K bug). Also, you can switch to different color schemes for that BIOS, I believe.