Erratic Keyboard Behavior (randomly)

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andresv
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Erratic Keyboard Behavior (randomly)

Post by andresv »

Hi guys, since a few days now I'm suffering from a failure in my STE.
The keyboard starts acting funny, pressing keys won't work or generate the wrong character.
This happens more or less randomly, sometimes the machine boots OK and sometimes the machine boots and the keyboard starts misbehaving.

Any ideas?

Agv
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exxos
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Re: Erratic Keyboard Behavior (randomly)

Post by exxos »

Clean keyboard header on the motherboard with IPA ?
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viewtopic.php?f=17&t=1585 Have you done the Mandatory Fixes ?
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rubber_jonnie
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Re: Erratic Keyboard Behavior (randomly)

Post by rubber_jonnie »

Perhaps remove the KBD microcontroller if it's in a socket and spray with contact cleaner and re-insert. Check the wires have not frayed where they connect to the keyboard PCB and they have continuity to the connector, and check the soldering on the mainboard connector.

Continuity check all the traces between the connector on the mainboard and the 6850 (U21 I think).

It is possible that the KBD PCB is cracked, so you may need to disassemble and check for that or bad solder joints, but watch out for the rubber domes.
Collector of many retro things!
800XL and 65XE both with Ultimate1MB,VBXL/XE & PokeyMax, SIDE3, SDrive Max, 2x 1010 cassette, 2x 1050 one with Happy mod, 3x 2600 Jr, 7800 and Lynx II
Approx 20 STs, including a 520 STM, 520 STFMs, 3x Mega ST, MSTE & 2x 32 Mhz boosted STEs
Plus the rest, totalling around 50 machines including a QL, 3x BBC Model B, Electron, Spectrums, ZX81 etc...
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andresv
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Re: Erratic Keyboard Behavior (randomly)

Post by andresv »

I was about to start removing the case screws (again) on my Atari STE but remembered that a few days ago I dropped my STM1 mouse on the floor and started to behave strangely. Apparently the left button micro-switch got smashed by the drop and not it "gets stuck".

So it seems that this is what was causing the keyboard to behave the way it did... don´t really know what that might have to do, but it is.

When I remove the faulty mouse the keyboard functions perfectly, so mystery solved.



Thanks!



Agv
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rubber_jonnie
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Re: Erratic Keyboard Behavior (randomly)

Post by rubber_jonnie »

andresv wrote: Mon Oct 04, 2021 1:36 pm I was about to start removing the case screws (again) on my Atari STE but remembered that a few days ago I dropped my STM1 mouse on the floor and started to behave strangely. Apparently the left button micro-switch got smashed by the drop and not it "gets stuck".

So it seems that this is what was causing the keyboard to behave the way it did... don´t really know what that might have to do, but it is.

When I remove the faulty mouse the keyboard functions perfectly, so mystery solved.



Thanks!



Agv
Ahh, good stuff :)
Collector of many retro things!
800XL and 65XE both with Ultimate1MB,VBXL/XE & PokeyMax, SIDE3, SDrive Max, 2x 1010 cassette, 2x 1050 one with Happy mod, 3x 2600 Jr, 7800 and Lynx II
Approx 20 STs, including a 520 STM, 520 STFMs, 3x Mega ST, MSTE & 2x 32 Mhz boosted STEs
Plus the rest, totalling around 50 machines including a QL, 3x BBC Model B, Electron, Spectrums, ZX81 etc...
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