IBM 5251 Beamspring Xwhatsit converter key mapping problem help.

Fkazim

16 Oct 2019, 04:08

Hello everyone I had finally finnished restoring my IBM 5251 Beamspring keyboard. I actually made a thread about the full restoration process here: viewtopic.php?f=7&t=22586. I seem to be having a problem where some keys are registering as the same keys. What I mean by that is that some keys output the same scan codes. Below is an image showing the specific keys that seem to be linked. If you guys could help me resolve this problem it would be much appreciated.

Thanks.
IBM 5251 linked keys.jpeg
IBM 5251 linked keys.jpeg (103.39 KiB) Viewed 1149 times

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ZedTheMan

16 Oct 2019, 18:56

Have you checked to see that the keys don't trigger each other's thresholds and that one doesn't override the other?

Fkazim

16 Oct 2019, 19:48

They do trigger eachother as they register as the same key. I just don't know why. I tried changing the thresholds but it's either I go low on the threshold and none of those keys I outlined register or I go higher on the threshold (141) and those keys In each square I outlined activate eachother. For now I have set left shift's pad to be ignored so my backslash works and I set the caps lock pad to also be ignored so that my tab key on top functions correctly.

Any help in fixing this problem would be much appreciated.

Fkazim

17 Oct 2019, 20:15

Any ideas to how to get the keys to activate independently?

Thanks.

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ZedTheMan

17 Oct 2019, 21:34

I forget, can you set the threshold of independent keys in xwhatsit? If so, can you change the thresholds to be low for all but one specifically?

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AJM

17 Oct 2019, 22:13

I would check, if the connector of the xwhatsit is lined up correctly with the pcb. The connector is wider than necessary. So it can be attached too far to the left or right. If this happens it can short two or more contacts, which might have such a strange effect.

Fkazim

18 Oct 2019, 01:27

Thanks for the advice will check that when I am back from my holiday.

Much appreciated.

Fkazim

28 Oct 2019, 10:05

Well I got back from holiday yesterday. I tried moving the Xwhatsit controller over on the edge connector to where it was all the way to the left side of the edge connector and it made my PC go absolutely insane with flickering black screening etc. So I don't think it is anything to do with the edge connector. any other ideas? I made sure the connector is definitely lined up correctly.

Thanks.

Fkazim

28 Oct 2019, 15:27

Any other ideas on this problem?

Please help.

Fkazim

29 Oct 2019, 19:49

Just Checked all the contacts on the edge connector and all seemed fine. Although I did still pull the capacitive pcb off of the backplate. I never realised how very thin the PCB is on the beamspring compared to the Model F's thick PCB. Anyway then I used some isopropyl alchohol and cleaned all the contacts but still no luck the problem stayed.

I really don't know where to go from here could it be the Xwhatsit that is causing the problem?

listofoptions

29 Oct 2019, 19:57

no its almost certainly the edge connector. ive restored a handful of 5251's its usually the only place they can stop working, even with corroded looking pcbs. get some 1k grit or higher sandpaper, and use some isopropanol to gently sand the connector. since you've got it apart already clean the pcb as a whole with a towel and either isopropanol or acetone. make sure there's ABSOLUTELY nothing on the flyplates, you might even have to clean them with a qtip and more iso.

Fkazim

29 Oct 2019, 20:55

OK will try that and let you know what happens I will probably report back this weekend really appreciate the input.

Thanks.

listofoptions

29 Oct 2019, 21:11

just make sure to be very careful in sanding that connector, you're only trying to break any oxide or light corrosion, if you see copper STOP!

Fkazim

29 Oct 2019, 21:29

OK will disassemble the keyboard again this weekend.

Thanks for the help.

Fkazim

09 Nov 2019, 01:06

I just finished sanding down the contacts on the edge connector. I can now see all the contacts are shiny but still have the same problem. Any ideas where to go from here?

Thanks.

Fkazim

Today, 10:51

So no other ideas?

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