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Thread: Keyboard error, press <F1> to enter setup OMG o_O

  1. #1

    Default Keyboard error, press <F1> to enter setup OMG o_O

    Hello everyone,

    first of all, sorry for my bad english, I'm Italian. I found this great forum jumping around with google

    I'm in trouble with my old 386 pc, I cannot identify motherboard brand/model, the amibios string is "30-01]1-ZZ1326-00101111-043091-HT18SX-0" and it has a 386sx onboard and 387 coprocessor on slot.

    Yesterday I tried to boot it after some year, 3 times it booted ok, after 3 times it freezed on boot with "Cmos error, default loaded" and "Keyboard error, press <F1>". Battery had some electrolyte out, and I've seen on some forum that cmos battery low may cause bios fault, so i unsoldered old ni/cd battery and soldered a new one, now I've only the keyboard error.

    Sometimes the keyboard seems running ok for 5, 10, 20 seconds, in one of this rare moments I've entered bios setup and set bios to not halt on keyboard errors, but i've not resolved my problem. Btw so I think that (fortunately) keyboard bios is ok.

    Tomorrow I will try to post some photo of the motherboard!
    Can someone suggest to me something to try to fix it? (I don't want to buy another one ) I've tried to put a deoxidant spray on the keyboard connector and checked the three fuses near this connector (I suppose that components marked as "FB" are fuses).

    Thank you in advance.

  2. #2

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    I've forgot to tell you that the three leds on the keyboard flashes at startup, even with the keyboard error.

    Tomorrow I'll try to re-solder contacts of the keyboard connector... hope it will fix the mobo

  3. #3
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    Quote Originally Posted by aSaSSinoooo View Post
    Sometimes the keyboard seems running ok for 5, 10, 20 seconds, in one of this rare moments I've entered bios setup and set bios to not halt on keyboard errors, but i've not resolved my problem. Btw so I think that (fortunately) keyboard bios is ok.
    It really sounds like the acid has damaged a copper track that is part of the keyboard circuitry, which makes sense because the battery is normally located near the keyboard connector/circuitry.

    It could also be a bad solder joint where the keyboard socket is soldered to the motherboard. Try powering on the machine with your hand pushing the keyboard plug slightly to one side, then try the other direction, etc.

    It could also be a bad keyboard. You don't have a spare to try?

    Quote Originally Posted by aSaSSinoooo View Post
    and checked the three fuses near this connector (I suppose that components marked as "FB" are fuses).
    No. FB is an acronym for ferrite bead. Think of them as a doughnut of ferrite that sits around the wire. They reduce RF signals getting in/out of the computer.

    Quote Originally Posted by aSaSSinoooo View Post
    I've forgot to tell you that the three leds on the keyboard flashes at start up, even with the keyboard error.
    Keyboards normally do that when they get power.

  4. #4

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    First of all, thank you for your prompt reply

    Quote Originally Posted by modem7 View Post
    It really sounds like the acid has damaged a copper track that is part of the keyboard circuitry, which makes sense because the battery is normally located near the keyboard connector/circuitry.

    It could also be a bad solder joint where the keyboard socket is soldered to the motherboard. Try powering on the machine with your hand pushing the keyboard plug slightly to one side, then try the other direction, etc.
    I tried this, but no results. I've seen something strange on a copper track, but copper tracks are covered by a green plastic sheet, and they seems to be tracks from ali to isa slots, not related to keyboard connector. Tomorrow I will post some photo...

    Quote Originally Posted by modem7 View Post
    It could also be a bad keyboard. You don't have a spare to try?
    Yes, I've 3 AT keyboards, any of these running on my 486 so i can exclude bad keyboard.

    Thank you!

  5. #5
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    Is the keyboard controller (a 40 pin DIP package usually near the keyboard connector) in a socket? If so, try removing it (gently) from the socket, give the pins a visual inspection and a bit of cleaning if corroded and then replace it. Sometimes, mechanical stresses will cause a socket to produce an intermittent connection.

  6. #6
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    When I powered up my 486 after being dormant for many years I found the battery electrolyte had eaten through some of the tracks and the mouse wouldn't work. (Serial port U/S)

    I put another board in and that worked fine for a day or so (after also cleaning off the electrolyte as this one had also rotted, but not as bad). There were a couple of tracks under the keyboard socket which I scraped clean and tinned, I also cleaned the crud off the DIN socket before I refitted it, but then the keyboard stopped working after a day or so. Although the tracks were supposedly OK when I fitted the board, powering it up must have finished it off as on examination one track had developed an obvious gap under the green lacquer and measured O/C. I scraped the lacquer off and soldered a wire across it and it cured the fault. So it seems the nasty stuff from your NiCd can cause more damage after you thought you'd dealt with it


    BG

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    Speaking from experience, battery electrolyte is nothing compared to cat urine when it comes to dissolving PCB traces...

  8. #8
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    Quote Originally Posted by Chuck(G) View Post
    Speaking from experience, battery electrolyte is nothing compared to cat urine when it comes to dissolving PCB traces...:puke:
    What! You mean that all this time I've been buying expensive chemicals to etch my boards, when I could have been using my cat's litter tray instead !

  9. #9

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    Thank you for your interest in my trouble

    Here are some photos of the board (sorry, i've not put imagese here because they are too big to fit in the webpage):

    First to change battery, board w/oxide and electrolyte tracks: http://i40.tinypic.com/2gxkzur.jpg

    After battery change, used a spray to clean contacts, I removed also AMI KEYBOARD BIOS and cleaned pins: http://i44.tinypic.com/24w57bs.jpg

    Zoom of another place covered by electrolyte and oxide: http://i41.tinypic.com/2zi1rvc.jpg

    Zoom of 3 copper tracks that seems darker than normal (2 biggest, 1 smallest near the resistor R3): http://i40.tinypic.com/124ja69.jpg

    It seems that the green protection over the copper tracks is intact, but tracks under are darker, do you think that they may be corroded?

    See you!

  10. #10

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    I'd start by testing for continuity/resistance on the suspect-looking tracks.
    Quote Originally Posted by aSaSSinoooo View Post
    Zoom of 3 copper tracks that seems darker than normal (2 biggest, 1 smallest near the resistor R3): http://i40.tinypic.com/124ja69.jpg
    That narrow track leading from the keyboard connector towards C5 is definitely worth looking at, as is the diagonal one passing the positive end of the battery (where does that go?). Looks like there's also a plated hole at the top centre of that photo that may need checking. R3 is also chipped but I don't think that should matter too much.

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