Re: Help with Gemlight GMB-386UMC , no post, no beep

Posted on 2022-10-25, 11:21

by

by Nexxen

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Have you tried changing bus speeds? JP1 & 2 I have a hunch on socket was removed and qfp was soldered on to get 40 mhz cpu on it. Blue resistor is used to deselect the pga socket. I could be wrong. Is cpu getting vcc correctly?

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Re: AT Keayboard connector not getting proper voltage (repaired)

Posted on 2022-10-24, 21:45

by

by Nexxen

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Well, I also bought this motherboard secondhand, could have been to its knees before I gave it the last blow 😀

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Re: AT Keayboard connector not getting proper voltage (repair help needed)

Posted on 2022-10-24, 20:29

by

by Nexxen

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

No idea how this could have happened. There was some grime underneath. Was there even a fuse in that trace? Looks like there was a short circuit and that trace literally turned into an electric heater, that soldermask looks cooked. No fuse. I thought about it and my best explanation is this, some …

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Re: What retro activity did you get up to today?

Posted on 2022-10-24, 18:41

by

by Nexxen

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Repaired a motherboard. Soldering is never ending 😀

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Re: AT Keayboard connector not getting proper voltage (repair help needed)

Posted on 2022-10-24, 17:42

by

by Nexxen

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

100% back to normal. Forgot to take a picture, but it's just some copper wires and solder mask. PCChips is a source for entertainment. No idea how this could have happened. There was some grime underneath.

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Re: AT Keayboard connector not getting proper voltage (repair help needed)

Posted on 2022-10-24, 16:15

by

by Nexxen

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Ok, I did a Necroware, i.e. I skipped the most obvious thing to realize it was the first thing to do. 😀 If you are in the chess world, "motherboard speaks for itself".

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Re: AT Keayboard connector not getting proper voltage (repair help needed)

Posted on 2022-10-24, 14:08

by

by Nexxen

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I have an M520 that had a bad solder joint on one end of the keyboard fuse. Likely it was never a good solder connection, but it probably worked until it was put in storage and years of dampness caused corrosion. The AT port itself also had cracked solder joints, but the fuse's connection was the …

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AT Keayboard connector not getting proper voltage (repaired)

Posted on 2022-10-24, 13:28

by

by Nexxen

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I powered on my 233MMX AT pc and I had no keyboard. Board is M530 https://theretroweb.com/motherboards/s/pcchips-m530#downloads (pics following) I took everything out and found the following: when I have keyboard plugged off // in: - clk +5V // varies from 0.** to 2.27 - data +5V // varies around 2. …

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Re: Toshiba Satellite 200CDS 810 - troubleshooting and general info (KBC error - trying to solve, help needed)

Posted on 2022-10-24, 09:55

by

by Nexxen

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

looks like pinout for keyboard matrix >internal keyboard connects to ALPS chip, (toshiba is keyb controller) and connects to T9934 too. cd4066 is switching between internal/external keyboard. I dont know how would they detect ext keyboard is plugged, does your PS2 connector have any extra pins? hmm …

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Re: Toshiba Satellite 200CDS 810 - troubleshooting and general info (KBC error - trying to solve, help needed)

Posted on 2022-10-23, 21:51

by

by Nexxen

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I'm desoldering the bios chip and reflash it. Maybe it's a corrupt data. I checked everything, but no broken traces, no evident damage; blown components. Unless I get the same model again I can't figure this out. Have no idea what keyboard pinout means.

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Re: Toshiba Satellite 200CDS 810 - troubleshooting and general info (KBC error - trying to solve, help needed)

Posted on 2022-10-23, 21:30

by

by Nexxen

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I made amistake, 2 and 6 are used as ext mouse/kbd signals. Internal and extaernal have separate paths. Didn't know. 5 - clock (goes to pins 4 & 11 H4066 - 2y 4y) 0.27V 3 - gnd 1 - data (to pins 2 & 9 - 1z +3 z) 5V 2 - should be nc but has 5V to pin 8 (3y) // is ext keyb data 4 - to pin 14 +V (Vcc) …

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Re: Toshiba Satellite 200CDS 810 - troubleshooting and general info (KBC error - trying to solve, help needed)

Posted on 2022-10-23, 20:30

by

by Nexxen

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I have the following readings on ext ps2 connector: 5 - clock (goes to pins 4 & 11 H4066 - 2y 4y) 0.27V 3 - gnd 1 - data (to pins 2 & 9 - 1z +3 z) 5V 2 - should be nc but has 5V to pin 8 (3y) 4 - to pin 14 +V (Vcc) 6 - nc but 0.09V to pin 10 (4z)

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Re: Toshiba Satellite 200CDS 810 - troubleshooting and general info (KBC error - trying to solve, help needed)

Posted on 2022-10-23, 16:40

by

by Nexxen

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

https://pdf1.alldatasheet.com/datasheet-pdf/v … S/74HC4066.html This chip goes to ext keyb, signals 3E and 4E have continuity to Gnd. But they should be active high. This means there should be V+ and not gnd?

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Re: Toshiba Satellite 200CDS 810 - troubleshooting and general info (KBC error - trying to solve, help needed)

Posted on 2022-10-23, 13:25

by

by Nexxen

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I just got a Toshiba Satellite 400CDT that was giving the "KBC ERROR" on boot up. Took the whole thing apart and the standby battery had leaked out of its heatshrink onto the "IC21" HC4044 chip by the keyboard controller, some of the legs had visible corrosion on them. I have a spare very dead …

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Re: Hi need some help please!

Posted on 2022-10-23, 11:21

by

by Nexxen

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Ok, starting with the obvious. 1) are HDD and CD-ROM correctly set to master/slave? 2) FSB speed? 3) is the card making a good connection in its slot? tried in another? 4) do you have another i/o card, ISA, to test things? Post high def pics of the motherboard. Rotate the middle pic, let it be easy …

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Re: Toshiba Satellite 200CDS 810 - troubleshooting and general info (KBC error - trying to solve, help needed)

Posted on 2022-10-23, 08:47

by

by Nexxen

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I just got a Toshiba Satellite 400CDT that was giving the "KBC ERROR" on boot up. Took the whole thing apart and the standby battery had leaked out of its heatshrink onto the "IC21" HC4044 chip by the keyboard controller, some of the legs had visible corrosion on them. I have a spare very dead …

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Re: Quickshot QS-202 joystick

Posted on 2022-10-22, 13:45

by

by Nexxen

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Manual + program Connector on the left is the culprit. I thought using some heat and cutting through the plastic casing. To be clear, the issue is the cables inside, some must have come loose or disconnected altogether.

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Quickshot QS-202 joystick (need some help troubleshooting)

Posted on 2022-10-22, 13:44

by

by Nexxen

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I recently acquired this joystick. There's an older topic I posted in but it's better to open a new one. The joystick buttons can be programmed to work as keyboard keys, basically key bindings. One connector is for game port, another is plugged in m/b keyb connector for power and signal, the last …

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Re: What retro activity did you get up to today?

Posted on 2022-10-21, 20:54

by

by Nexxen

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

FIred up my M321 and the keyboard doesn't work. Tested another one and no joy. Keyb no. 1 is good on another pc. I now have to get everything out and see what's wrong 😀 I like surprises like that water buffalo in Apocalypse Now.

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Re: I got an ASUS K7M 1.04 motherboard recently. Encountering issues

Posted on 2022-10-21, 20:32

by

by Nexxen

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Could you inspect te board with a magnifying glass to check if there are some obvious cuts on traces? Time and effort yields eventually. If it beeps it speaks, just gotta figure out the language 😀 Ok, enough pep $hit.

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