Random Interestingness on Omron B3G-S

User avatar
hellothere

18 Apr 2022, 00:29

Amber. I bought one of these. Mine is, cosmetically, a little better.

Chain of events:
* No power/lights. Bad 5 pin DIN to PS/2 adapter. Replaced.
* Approximately 10 keys weren't working, at all. As mentioned elsewhere, my new fix is to spam a key a zillion times to see if it'll register. Fixed two keys. A couple worked every now and then.
* There were maybe two dead keys in the function line row. I desoldered all the good ones, desoldered the bad ones in the alphanumeric block, then swapped the switches.
* Now the ESC key registers an entire diagonal row, like 5 t h m. Two or so keys in the numeric row work. Maybe two or three other random keys work.

At this point, you may have noticed that I didn't say I resoldered ALL the switches. I did so and all but two are consistently not working and four or so are inconsistent.

I was wondering if anyone else has seen this and, if so, this is related to the fact that the Omron switches have three legs. I've left keys unsoldered on Alps keyboards and I haven't seen this behavior.

User avatar
Polecat

18 Apr 2022, 00:57

If the two connected legs were used as a jumper, to eliminate the need for separate jumper wires (or a double sided PC board), then having one of the two internally connected pins left unsoldered would cause anything past that point on a row or column not to work, and would cause that switch itself not to work if the unsoldered lead is on the "active" side. That makes more sense to anyone who's tried to lay out a single sided PC board without using jumpers.

edit: having one key activate an entire row suggests there may be multiple switches that are shorted internally or stuck on.

User avatar
Morron

19 Apr 2022, 10:50

hellothere wrote:
18 Apr 2022, 00:29

* Approximately 10 keys weren't working, at all. As mentioned elsewhere, my new fix is to spam a key a zillion times to see if it'll register. Fixed two keys. A couple worked every now and then.
I found that manually shorting the stubborn switches with a jumper got them started, and then spamming would make them work consistently.

User avatar
JP!

19 Apr 2022, 17:19

Morron wrote:
19 Apr 2022, 10:50
spamming would make them work consistently.
This was all I needed to do on was of my boards! I had < 10 keys that would not register. Out of frustration I spammed one a few times in quick succession. To my surprise it worked. I tried it on the other with similar success. One key was extra stubborn but I didn't give up and eventually I had all keys working consistently. :D

User avatar
hellothere

13 May 2022, 17:16

So, I bought another keyboard with Omron B3G-S. This time, it's a Chicony 5161A. Apparently I'm cornering the market on Omron switch keyboards. This one has only two keys that are an inconsistent problem: E, which chatters or just doesn't register, and the right shift, which sticks.

Again, spamming some of the keys made them work properly. I started with 7 bad.

I can't find the link I had on opening these switches. Anyone got any info?

User avatar
Muirium
µ

13 May 2022, 20:41

‘DT Wiki’ wrote:The switchplate in the B3G-S series is a partially sealed unit: the front panel affixes to the back panel using melted plastic lugs. The contact bridge fits so tightly into the back panel that it is virtually impossible to remove it. The centre leg is also fitted in such a way that it is impossible to remove it: the movable contact lug is above a square block of metal that is walled in on all four sides, with the leg protruding from a hole in the plastic. It is possible that the plastic is moulded in around the metal, as it does not appear possible to assemble the switch. No switchplate has ever been sighted fully disassembled. In comparison, the Alps switchplate is a simple sandwich of metal and plastic layers that can be manually disassembled and reassembled with very little damage.
Is your middle name Houdini?

User avatar
hellothere

14 May 2022, 17:52

Well, I don't think "Houdini" would really fit me all that well.

Yes, I'm aware of what the Wiki says, however, I think the info really applies to the switchplate and not the entire switch. I'm still pretty sure I remember seeing a take-apart, but it wasn't on Deskthority ¯\_(ツ)_/¯

If someone comes across something like that, RSVP.

User avatar
Polecat

14 May 2022, 19:45


User avatar
hellothere

19 May 2022, 19:52

Polecat wrote:
14 May 2022, 19:45
Perhaps this will help:

https://forums.arcade-museum.com/thread ... es.417705/
That's exactly it! Thanks very much!

User avatar
hellothere

19 May 2022, 21:11

Review:
My below comments are mostly from using the Chicony, not the Wang: the Wang has a lot of keys that need help. Also note that my current two favorite keyboards are a Abko 935P capacitive and a Realforce R2 Topre, both with 45g weighting.

I like the Omron. A lot.

FEEL: A happy medium of IBM buckling springs, brown tactile Alps, and Kailh Box Jade. It is a bit too heavy for me, but I've already mentioned that l like keyboards with a bit lighter switch. However, it's rapidly growing on me, just like the brown Alps did. It's really crisp and satisfying.

SOUND: Very close to an actual typewriter, although muted. It's much louder than the Kailh and the Model M/F, I think. The sound is also more crisp and higher pitch.

Now, for the elephant in the room or, in my case, a 90lb dog: reliability.

As mentioned, when I got the KB, it had 7 bad keys. During the week-ish that I've been using it, I've occasionally had key ghosting/repeating, but this happens less often the more I type. The E key is now working again. The right Shift still occasionally sticks, but it's better. However, note that I haven't done any cleaning or other work at all. So, it might just be that you have to use the keyboard often for it to work properly.

I have not tried amber Alps. I'd love to compare the two.

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