Beam Spring IBM 3278 A02 restoration

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02 Aug 2014, 10:58

Today my IBM 3278 A02 Beam Spring Keyboard arrived :) ... WHAT A BEAUTY!!! ...
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... and it is in worse condition than i hoped. :(

Some Brass parts inside are heavily corroded and so it seems likely that it was moist or even wet (with hydrofluoric acid or something similar -.-). I hope that the PCB and the switches are ok (the liquid shield is in good condition but the brass underneath is corroded around every switch what makes me worry - the switches are all pressable and nothing is stuck though). Bevor having a look at them i want/need to remove the Keycaps (sturdy little bastards :lol:, one need a looooooooot of patience to remove them... will take some hours, literally).

From the outside (case) it is besides this maaaaaaaaaaassive amount of dirt it is ok aside from some minor imperfections (some scratches at one edge of this black led holder thing at the top, some cracks in the painting, corroded spring and axis from the plastic-cap of the manual and keys are more or less shiny).

Here are the first scary pictures:
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Sorry for the Picture quality, i only have a Tablet-PC-Camera atm.
P.S.: I am searching for spare parts for the restauration: ... t8500.html pleas PM me if you can help :)
Last edited by Monster-Toys on 02 Aug 2014, 18:41, edited 3 times in total.

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02 Aug 2014, 13:11

Nice! This is one of my favourites. I'm a big fan of the colourful keycaps. I'm very jealous. Where did you manage to find this one?

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02 Aug 2014, 13:14

It was a 24h Ebay Auction, but atm there is no need to be jealous, i am unsure if i can bring it back to life.

I opened it before removing the Keycaps. First the PCB looked ok after cleaning but i spottet this (less strong in some other places, too):
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I am not good with electronics... so: is this as fatal as it looks to me?

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02 Aug 2014, 13:41

I'll let Xhwhatsit and the other Keepers of the Beamsprings speak, as they actually know about this stuff. But as someone who's looked at a few stripped down photos of these, yours doesn't look too bad. They are strong. I bet you can bring this one back to life!

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Wild Duck

02 Aug 2014, 13:45

It's a loss. I'd pass it off to some gullible collector.

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02 Aug 2014, 13:47

Uh, oh, good point. Maybe you ought to step aside for us wizards…

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02 Aug 2014, 13:54

I just started to think of ways to recreate or repair such sort of pcb (lasercut copperfoil and beef it between layers of thin acrylic plates or something like that. But I do not understand enough of electronics and capaciti-stuff atm to know if this is possible, have to read in it first ... i WILL write on this board some day :evil: (i do not plan to give it away but if I would, there is already a waiting list wit top spot taken ^^).

Hopefully i am just falsely alarmed *keeps fingers crossed*
At least all flyplates/switches seem to be ok even after removing the pcb as far as i can tell.

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02 Aug 2014, 14:00

The corrosion in the corner is concerning, so you're right to focus on that. The PCB is typically one of the last things to go wrong, usually you'd be talking about metalwork on the case interior.

Good and bad news about capsense PCBs, as I asked Xwhatsit about these for an unrelated project of mine earlier. Bad news: they're multi layer and this matters. The capacitance these boards are sensing is actually all between pads and layers on the PCB. The switch mechanisms merely alter it. Good news: Such PCBs are well within our ability to get manufactured these days! Even flexible ones like in the Model F (and I presume beam spring?).

But I suspect yours still works. It's just a hunch. I'd investigate where to fit Xwhatsit's controller!

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02 Aug 2014, 14:09

Metalworks and get rid of the corrosion is not a big problem i think, just some work.

The PCB is flat and non flexible (indeed it is very stiff).
I am not that bad with cad and as far as i can see there are two layers of conductive stuff and three layers to sandwich them. Designwise (not sure if it will be precice enough for this capacitive electronic stuff wich is sorta magic for me^^) it should be doable to recreate it with home equipment but ... will think of it later if there is a need to do so.

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02 Aug 2014, 15:55

Thanks for opening this thread, gives me a chance to sneak my pictures, in, too.

Some of you might know that I got the same model from the same seller as Monster-Toys a few days earlier over (And no, Monster-Toys' was the last one the seller had).

I mainly want to show some key caps here, because that's where I started so far.

Lots of large pics ahead:
When my keyboard arrived, a first look showed that it had this frightening problem:
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Someone obviously had decided to renounce the Vaterland (a popular notion amongst Germans back in the 80s when this keyboard was used), and scribble a US layout directly on the keys. There's nothing to say against the US layout, especially for a programmer,, but ... now that we won the world cup and all ...

And in fact, after a night of this and the loving use of a toothbrush and a tiny bit of toothpaste here and there,
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it's fortunately much better now:
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Roll call after the cleaning (I didn't take out the space bar):
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Roll call
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As you can see, the function keys on the left and right side of the board don't have row profiles like the alphanumerical keys, but all of them have the same profile. This is welcome because it means they could be swapped around later if needed...

The longer keys have stabilizing "feet", which is why they stand out in the previous picture.

Some of my favourite keys on this board:
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Start and Stop
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These are of course double shot keys. Strangely, there are two different designs of alpha keys on this board. On some, the mount is part of the first shot, on others it seems to be part of the second shot.

Except for the space bar, there are no keys that have real stabilizers with wire. Instead, the longer key caps only have "feet" that help stabilizing the key when pressed down on the side. Real stabilizers feel much better of course and are more effective.
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key caps upside down
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The return key even has this strange form:
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The front legends are not doubleshot, they are printed with obviously different methods for the black and white keys. On the white keys, the black front legends feel like they're carved in, while on black ones they feel like they stand out.

In any case, the key caps are really beautiful. I can imagine that they already looked kind of outdated when this keyboard was used though. The board was made on August 05, 1980 in Greenock. In 1981, the IBM PC and first Model F keyboards appeared with their cylindrical keycaps and the beige that should haunt computer design for the years to come.
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white key
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black key
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The keyboard itself looks teethless right now:
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board wo caps
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The protective foil is brittle, but in much better shape than on my first beam spring board. I won't take it off for as long as I can afford. Mind the crud of decades in the pictures.
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I haven't really looked much deeper yet, but it seems like mine is pretty corroded, too. We'll see.
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controller and corrosion
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Last edited by Halvar on 02 Aug 2014, 16:13, edited 1 time in total.


02 Aug 2014, 16:10

Halvar wrote: (I didn't take out the space bar)
That was a good decision. You can easily break the stabilizer bar holders on the space bar. They should have made them sturdier and used more plastic.

(Mine arrived already broken.... "pre-broken", saving me the trouble of breaking it myself ;) )

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02 Aug 2014, 16:11

One particular thing about this model is the so called "Operator Control Panel" above the keyboard that is actually a separate device in the same case with its own cable and no connection to the keyboard at all. It's rather simple and passive, featuring 5 LEDs and 3 switches and no electronics at all.
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ocp cable
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02 Aug 2014, 16:25

mr_a500 wrote:
Halvar wrote: (I didn't take out the space bar)
That was a good decision. You can easily break the stabilizer bar holders on the space bar. They should have made them sturdier and used more plastic.
Thanks for the warning, I'm afraid I will have to do it rather sooner than later given the state of corrosion ... :?

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02 Aug 2014, 16:42

Superb pictures. Really getting a feel for just how much I want one of these, and yet how much work both of you have to do. Fingers crossed you get there.

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02 Aug 2014, 16:56

Nice Pics (I should buy a camera). I am happy all the red is gone :) .

Here are pics from my "PCB inspection":
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I cleand it as good as possible atm (tomorrow i will totaly dissemble it and start with the fight against corrosion) and put it back together to pull the keys. Most were more easy then i thought but some of them were a ten minutes wiggle fight ( I won) and they are now taking an overnight bath in water with Spüli (yes, here in germany we have dish liquid with röck döts 8-) ).
I also removed the space bar. I popped the stabilizer out of the holder carefully before removing the key (one side, was easy, the other one uiuiui).
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I decided to get rid of the liquid shield (board does sound and feel much better without it imho) but i will rack my brain to build an better sounding alternative.
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Have sooo many ideas what to do with this Operator Control Panel ^^
Last edited by Monster-Toys on 02 Aug 2014, 17:50, edited 2 times in total.

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02 Aug 2014, 17:02

P.S.: I want one of these :shock:
Last edited by Monster-Toys on 02 Aug 2014, 17:14, edited 1 time in total.

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02 Aug 2014, 17:13

Take the video ID (/watch?v=XXXXXXX), then do [ youtube ]XXXXXX[ /youtube ]

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02 Aug 2014, 17:15

Thx scottc :)


02 Aug 2014, 17:31

Be careful with those keycaps. Some (all?) of the front-facing legends on beamsprings were printed rather than double-shot.

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02 Aug 2014, 17:37

In case you haven't yet, check out the solenoid action in this clip (starting at 1:50 )


02 Aug 2014, 17:40

quantalume wrote: Be careful with those keycaps. Some (all?) of the front-facing legends on beamsprings were printed rather than double-shot.
Yes, daedalus found this out the hard way:

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02 Aug 2014, 17:46

THX for the warnings :)


03 Aug 2014, 00:54

Hey Monster-Toys, sorry this turned out to be a bit of a let-down for you! It looked really nice in the eBay auction.

Still, I don't think it's as terminal as it looks. You're right in that the major concern is the PCB itself. That said, the picture you showed up the top which has obvious bubbling and corrosion only shows corrosion in that big thick trace. This is simply just a ground plane/ring which runs around all of the sensitive stuff to make it more resistant to electrical noise. It's still not ideal having this a bit damaged, but given that everything is also sandwiched inside a big thick metal enclosure (which is also tied to signal ground by the controller), I'd be surprised if it still didn't function OK.

Also, that corrosion may just be on the surface between the solder mask and the copper & HASL plating; as I recall, that `shield ring' ground trace goes all the way around the outside of the keyboard, so it's not the end of the world that it's broken in one place. It may even be repairable by scraping away the solder mask in that place and either dumping heaps of solder on (would look pretty horrible) or laminating a piece of copper foil on in its place.

I'd give it a try first without trying to fix anything first—you have a Beamspring controller already don't you? Or was it a Model F controller? I'm not near my spreadsheet right now so I can't recall... If it does turn out to be non-functional, as Murium mentioned it wouldn't be impossible to manufacture a new PCB (or `pad card' as IBM called them). I'd be way more worried if there was actual mechanical damage to the keys and internals themselves, as it's currently impossible to manufacture replacements, and it's very hard to get spare parts.

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03 Aug 2014, 10:18

Thx xwhatsit,
I have a model f controller for my kish but will order a beam spring controller and solenoid driver within the next days.
This "bubbling" is not only in this place but there one can see it best. Will make some other photos today.
What exactly is this bubbling? The PCB seems to be "waterproof" to me (or did moisture soake in from the sides of the pcb somehow?).
I hope it will work. I fear making a multilayer pcb that size will be expensive but doing the layout could be fun^^ (i would use autocad, is it possible to import autocad data into some pcb-design-software?)


03 Aug 2014, 10:47

I'm not sure what the bubbling is either; clearly whatever nasty fumes corroded the surface treatment on the bottom plate is pretty aggressive towards metals. I don't think either was just moisture, unless it was some salt/sea water or something like that.

A PCB that size may be one of the few remaining times where a DIY etch makes financial sense. You wouldn't even need to get it into a PCB package then, simply drawing it in CAD (if that's what you're comfortable with) and printing it out onto transparency or for the toner-transfer method (it's not exactly high-resolution, this board design) would suffice. There are also plenty of home-laminate solder masks, which becomes even easier because you don't actually need to expose any of it (apart from the edge connector, but that would be simply enough to just mechanically cut around). I'm not actually sure how necessary the solder mask is to be honest (there is that plastic/vinyl sheet between PCB and bottom plate, but direct contact with the beams themselves may cause minor conductivity? I don't know!).

Post up some more photos, if it's just confined to the shield ring you might be in luck.

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03 Aug 2014, 16:19

I Used my DIN A3 scanner to scan the PCB. Here is the detail that worries me most:
3278 pcb.jpg
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Seems that i have to made a PCB myself then (even if it works now it is questionable if it will not get worse over time).
Would it be possible to cut it out of copperfoil and gluing it onto a thin acrylic plate instead (and then mask it) instead of etching?(If yes, how thick should the copper be?).
You see i am a total beginner with this stuff.


03 Aug 2014, 17:49

It does not look that bad have you checked the continuity and see if any of the tracks are broken ?

I am not 100% but the way older PCBs where made you do get some amount of bubbling as they where done with tin roll traces ? I don't know if this is the case on this PCB.

If that is the only bad corrosion could you not just remove the solder mask and tin the traces ?

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07 Aug 2014, 21:00

Today in "Monster Toys loves his Beam Spring Board": Derust
Removing the switches
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Removing the "IBM Nasty Foam"®
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Taking a 24h vinegar bath (the metal parts, not me)
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After the bath and cleaning
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Rust converter applied ...
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... to all metal parts to prevent them from further rusting
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This will sit for 48 hours, then i will clean it and do two more 48h runs with the rust converter to err on the side of caution.

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07 Aug 2014, 21:03

This beam spring really went to the right place!

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07 Aug 2014, 21:52

Great job! I'm anxious to see how it turns out.

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