40-pin IC means a chip on the motherboard with 40 pins - the little wire legs that are usually soldered to traces on the board. In this case, the idea is that maybe this chip is not soldered onto the board, but pushed into a socket from which it could be prised and hence replaced, with a similar chip from another board.

I had this happen on a few of my boards. It turned out to be a blown keyboard fuse. You might want to look into that.

They are usually small yellow cylinders located beside the keyboard port, though they may come in other colors as well.

ratfink wrote:

40-pin IC means a chip on the motherboard with 40 pins - the little wire legs that are usually soldered to traces on the board. In this case, the idea is that maybe this chip is not soldered onto the board, but pushed into a socket from which it could be prised and hence replaced, with a similar chip from another board.

Ah, please forgive my ignorance, I understand now. The only chip on the mobo which appears to be replaceable is the BIOS chip. All other chips appear to be soldered on to the mobo.

@Anonymous Coward,
I see a tiny rather fragile looking "thin green thing" with the wording "125V/3A fuse" nearby. I can only inspect it from certain angles. I cannot inspect its underside, as it's so close to the mobo. Visually, it appears OK. It's really interesting, because my other Asus PVI-486SP3 board (which is a 1.22 revision, the initial board in question being a 1.2) doesn't have this "green fuse", but a chunkier looking black "cyclinder thing" with the same "fuse information" written on the mobo. Perhaps they upgraded this keyboard fuse, after customers reported having problems with their keyboards?

All of this is making me increasingly aware that I lack soldering skills (and equipment). Hmmm.

I don't suppose there's a way of bypassing the socketed keyboard connector? It seems to be a potential Achilles' heel.

(Edit: Vogon's user elfuego said that the chances of a PCI usb controller, which unfortunately I don't have ATM, working are pretty low.)

The keyboard lights wouldn't flash if the fuse was bad.

When my fuse was bad, for some reason the lights on the keyboard still flashed. I'd check the fuse anyway.

h-a-l-9000 wrote:

The keyboard lights wouldn't flash if the fuse was bad.

The mystery deepens.

h-a-l-9000 wrote:

Controller, not connector. Black rectangular IC with 40 pins.

I'm sorry, I understand now. On a different mobo (a UMC board), I can see a black rectangular chip with 40 pins. It has the wording "AMIKEY (tm) - 2" written on it. This chip appears to be replaceable - just like a BIOS chip. Unfortunately however, on the mobo in question (the Asus board), this AMIKEY 40 pin chip seems to be soldered on to the mobo.

Anonymous Coward wrote:

When my fuse was bad, for some reason the lights on the keyboard still flashed. I'd check the fuse anyway.

I would like to check the fuse, but I have no idea (or equipment) how to do this. I know how to change a fuse in my mains power plugs. But this "thin green thing" which is soldered on to the mobo - to coin a phrase - that's a "different kettle of fish". I wonder if there's anyone in the UK (to keep postage costs down) who's interested in this kind of challenge? I mean, I am interested, but I don't own the equipment or have the know-how to investigate this kind of situation. Unless of course, it's a bit easier than I imagine..?

you can get adapters so you can use a ps2 keyboard

Davros wrote:

you can get adapters so you can use a ps2 keyboard

Yep, I tried that, but alas no joy.

(I tested my new keyboard adapter on two other 486 mobos, and they both worked fine with a ps2 keyboard.)

> When my fuse was bad, for some reason the lights on the keyboard still
> flashed. I'd check the fuse anyway.

Either your fuse was not completely blown or your keyboard was so extremely power saving that it could supply itself somewhat from the data lines...

Checking the fuse should be possible using a regular multi-meter.

Anonymous Coward wrote:

Checking the fuse should be possible using a regular multi-meter.

Multi-meter added to RG100's bottomless pit-like retro shopping basket! 😉

Or you can use a coin battery, some wire, and an LED.

Actually, you can just use a wire and solder the the two ends of the fuse together temporarily. While you shouldn't leave it like that, in the short term it will at least tell you if the fuse is the problem or not.