VOGONS


First post, by BurnedPinguin

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Hi vogons, I am having an issue with a "PCI486 V1-HJ3" 486 motherboard, I saw a post about it on here but it didn't help much. Every time it turns on, it gives me a keyboard Interface error, and the 3 lock lights on the keyboard flash 2 times a second, non-stop. Things I have tried so far are:
• Replace CMOS battery
• Reseat BIOS chip
• Different ram
• Remove the socketed cache
• 2 different, known working keyboards (tested on other systems)
• Resolder keyboard connector
• Remove corrosion from SMD chips
The motherboard has an AMD-X5 133adw, aka 5x86-p75. 2x8mb edo sticks (have tried 1x16 fpm stick), and 256k real, socketed cache. I have tried multiple graphics cards too. The bios string is: "41-C101-428027-00101111-101094-ALI87/89-U" A picture of the very motherboard follows. Any help is appreciated, and thank you for your time!

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Last edited by BurnedPinguin on 2021-01-21, 20:33. Edited 2 times in total.

Reply 1 of 11, by majestyk

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Damaged soldering points at the keyboard connector come to mind.
The keyboard controller would be a possible culprit, too. It´s integrated in the super-io here.
I would carefully check the 5 soldering points at the kb-connector (on the downside) and around the super-io with a good magnifying glass before replacing any components.

Reply 5 of 11, by quicknick

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Can't find a datasheet, but AFAIK the LG/GoldStar Prime chip doesn't include a keyboard controller.

The M1487 southbridge does include a KBC, and while it can be configured to work with an external one I think in this case the internal one is employed. Pin 5 is KBCLK, pin 6 is KBDATA so check if you have continuity from these to the corresponding pins of the KB connector.

Reply 6 of 11, by BurnedPinguin

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Now that I look at it, all of the surface mount chips have corrosion on some pins. So I will clean that once I get hold of magic liquid (isopropyl alcohol) that does that (or I might just use vinegar or baking soda but I don't know if this works well)

Reply 9 of 11, by quicknick

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With keyboard plugged, check if you have +5V at the connector. Sometimes the fuse or an inductor fails to a high-resistance state, and voltage to the keyboard port drops below what the keyboard needs for proper operation.

Reply 11 of 11, by B_Cik

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I haven't figured out the best place to ask this question.
I am trying to run a program using a special keyboard that connects through PS2. This keyboard has lights that need direction from the computer to light up. I have the program running and all keyboard functions work, but the lights do not come on when they are supposed to.
Do I need a setting to send an output through the ps2? I have also connected through USB as well with the same results.