Failing keys on IBM Model M

[Winrar]

Hi.

I own an IBM Model M keyboard (part number 1394550 spanish layout, built on 1/31/97). I don't know if it is built by IBM, Lexmark or whatever. I just love it.

A couple of days before it went 14 years old it broke. There are keys
(z,n,-, space and every arrow except for the upper one) that don't work (I mean, pressing them does not produce any output in the screen).

The problem isn't of mechanic nature, because springs are fine and keys
feel and sound as good as they always did.

I'd like to know if you can advice me with my keyboard. From
the description I gave you, could you say if the keyboard is repairable
by cleaning or some other easy way? Should I bother trying to get it
repaired? I love that keyboard so much that it will be sad for me to let it
die.

Besides, I've acknowledged how much i miss my keyboard and I have been lucky enough to be able to buy not one but two original IBM-manufactured Model Ms (both spanish but different layouts), and I am seriously considering getting one of those Unicomp keyboards, even when shipping to Europe will cost me as much as the keyboard itself.

How do Unicomps compare to my keyboard? Are they worth the money for someone used to Model M or I'd better go with Cherrys or Das?

TIA

[itlnstln]

Unicomps (internals) are pretty much the same (other than some controller upgrades/changes); there are some threads in the Reviews section you can look at.  Personally, I would keep the case and key caps and order just the guts from Unicomp.  I think it's a little cheaper that way, and due to the way they're manufactured, they are a ***** to take apart and clean.  I would just give Unicomp a call or send them an e-mail, and they should be able to help you out.  From what everyone here has said, they are a pretty friendly and helpful group.

[Winrar]

Unicomps (internals) are pretty much the same (other than some controller upgrades/changes); there are some threads in the Reviews section you can look at.  Personally, I would keep the case and key caps and order just the guts from Unicomp.  I think it's a little cheaper that way, and due to the way they're manufactured, they are a ***** to take apart and clean.  I would just give Unicomp a call or send them an e-mail, and they should be able to help you out.  From what everyone here has said, they are a pretty friendly and helpful group.

I've already contacted them. A very nice guy called Chuck answered my mail and the lots of questions I asked him.

He adviced me to remove keys and reseat them and told me that I should send them the keyboard for repairing (total: 130$) if that didn't work. I am obviously not sending the keyboard, but I'd probably purchase one of their keyboards.

My keyboard is very easy to clean. I can remove keys (two-pieced), clean, dry and put them back. I did that dozens of times and was very easy. Aren't Unicomps built that way?

Besides, I was mainly asking about the keyboard feel when typing. How do Unicomps and vintage Model M keyboards compare when it comes to sound and feel?

One more thing: How 'true' is my Model M. It has part number 1394550,  spanish layout and was built on 1/31/97. No Lexmark or Unicomp traces in the sticker, but AFAIK IBM didn't manufacture Model M in 1997. Is it a real Model M or is it just a buckling spring IBM keyboard? It has gray IBM logo with blue letters on top left corner of keyboard and looks exactly like this one:



Best regards.

[itlnstln]

I can't help you with the manufacturing info, but in order to fix/clean your M, you are going to have to do some "damage" to get it apart.  You can't actually access the membrane the hammers sit on since there is a "sandwich" of parts that are riveted together.  You will have to break the rivets to get in there, then put it all back together.  Not an easy task.  This thread will show you what you're in for: http://geekhack.org/showwiki.php?title=Island:6615

[microsoft windows]

I've already contacted them. A very nice guy called Chuck answered my mail and the lots of questions I asked him.

He adviced me to remove keys and reseat them and told me that I should send them the keyboard for repairing (total: 130$) if that didn't work. I am obviously not sending the keyboard, but I'd probably purchase one of their keyboards.

My keyboard is very easy to clean. I can remove keys (two-pieced), clean, dry and put them back. I did that dozens of times and was very easy. Aren't Unicomps built that way?

Besides, I was mainly asking about the keyboard feel when typing. How do Unicomps and vintage Model M keyboards compare when it comes to sound and feel?

One more thing: How 'true' is my Model M. It has part number 1394550,  spanish layout and was built on 1/31/97. No Lexmark or Unicomp traces in the sticker, but AFAIK IBM didn't manufacture Model M in 1997. Is it a real Model M or is it just a buckling spring IBM keyboard? It has gray IBM logo with blue letters on top left corner of keyboard and looks exactly like this one:

Show Image

Best regards.

It's a perfectly  "true" Model M. It's more or  less the  same as the ones  IBM  made.

What you may want  to consider is  taking  apart your keyboard and inspecting the keyboard assembly inside for broken rivets.

The  insides of your Model M consist of  the  mainboard(s) and the keyboard assembly. The assembly has a black plastic part and  a metal  plate that hold the  springs and  keys in  place, and  house the  mechanisms. The plastic  and metal  plate are held together  by plastic  rivets which are prone to  breakage.

Since most  of the  keys that  failed on  your Model  M  are on  the  edge of the  assembly, rivet failure is the  likely culprit in this  case.  There's a  guide here to  replacing  broken rivets.

Now you don't need to  replace all of  the keyboard rivets in  order for  it  to work properly. Only the broken ones.

[Winrar]

It's a perfectly  "true" Model M. It's more or  less the  same as the ones  IBM  made.

I'm happy to read that. But building date is 1997. It really comes from IBM?

The assembly has a black plastic part and  a metal  plate that hold the  springs and  keys in  place, and  house the  mechanisms. The plastic  and metal  plate are held together  by plastic  rivets which are prone to  breakage.

Since most  of the  keys that  failed on  your Model  M  are on  the  edge of the  assembly, rivet failure is the  likely culprit in this  case.

This makes sense. Keys don't feel loose and the clicking is perfect. Maybe the rivets broke and the upper mechanism can't reach the bottom membrane.

I am hopeless in manual jobs, but my dad is ace, so I will forward that info to him and we'll see if we can fix it. This will happen in 2 or 3 weeks, as I am far from home and my dad and keyboard are there.

I'll keep you updated about the process. Thank you very much.

[theferenc]

A unicomp would be essentially identical to your Model M. I have a Customizer 101, and several Model Ms, and I love them all. It won't feel exactly the same, as the springs will be new, rather than 14 years old, but I would wager it actually feels better.

I feel the Customizers are definitely worth the money.

Oh, and I think microsoft windows is right about the rivet issue.

[itlnstln]

My feeling is that unless you really want to do the nut/bolt mod, I would just get a Unicomp and swap the internals.  That said, it does sound like they want a lot of money to fix yours, but maybe they don't typically stock Spanish layouts.

[Winrar]

A unicomp would be essentially identical to your Model M. I have a Customizer 101, and several Model Ms, and I love them all. It won't feel exactly the same, as the springs will be new, rather than 14 years old, but I would wager it actually feels better.

I feel the Customizers are definitely worth the money.

Fantastic. I'll get one then. Probably with USB and Windows keys. I have vintage ones already.

Besides, I'm growing a nice Model M collection. Just purchased the variant with two rows of function keys on the top and a bunch of extra weird keys (with full spanish layout). This one has a DIN plug, though, and comes with a green screen. This was a kind of dumb terminal, but the keyboard is superb. And it was really cheap.

The vendor will contact me every time he receives a Model M, so I am off to become a real IBM Model M collector.

[Winrar]

My feeling is that unless you really want to do the nut/bolt mod, I would just get a Unicomp and swap the internals.  That said, it does sound like they want a lot of money to fix yours, but maybe they don't typically stock Spanish layouts.

It's not that much money. They charge $30 for the repairing work, but there is and additional $50 + $50 cost for shipping. They are not asking that much. Shipping a 7+ pounds package across the Atlantic Ocean much likely costs those 50 bucks, and the keyboard would have to travel to the US and then return to me again.

I'm getting the Unicomp with modern bells and whistles and also I'll try to repair the old keyboard by my own means. I'm not sending it to repair, but in such case they wouldn't need to touch the layout, since every single key works flawlessly.

[Daniel Beaver]

This is almost assuredly a problem of popped rivets, as others have mentioned. Most telling is that all the keys you mentioned are directly adjacent to rivets. The symptoms you describe are typical; broken rivets don't usually interfere very significantly with the mechanical action of the buckling spring, so you'll still feel the snap when you click. But without something hold the membranes firmly, the hammers may not bridge the membrane.

In any case, everyone else's advice in this thread is sound. Your logical choice of action is: buy brand new Unicomp, or attempt a bolt mod.

[Daniel Beaver]

This is almost assuredly a problem of popped rivets, as others have mentioned. Most telling is that all the keys you mentioned are directly adjacent to rivets. The symptoms you describe are typical; broken rivets don't usually interfere very significantly with the mechanical action of the buckling spring, so you'll still feel the snap when you click. But without something hold the membranes firmly, the hammers may not bridge the membrane.

In any case, everyone else's advice in this thread is sound. Your logical choice of action is: buy brand new Unicomp, or attempt a bolt mod.

[Winrar]

This is almost assuredly a problem of popped rivets, as others have mentioned. Most telling is that all the keys you mentioned are directly adjacent to rivets. The symptoms you describe are typical; broken rivets don't usually interfere very significantly with the mechanical action of the buckling spring, so you'll still feel the snap when you click. But without something hold the membranes firmly, the hammers may not bridge the membrane.

I'm almost sure this is the problem. I can even try to hold both plates together with tweezers or clips or something like that.

[keyb_gr]

BTW, Ms were made up to '99 or so. If the label says "Manufactured in the United Kingdom", which would be likely for a European layout sample, it left IBM's factory in Greenock, Scotland.

[Winrar]

BTW, Ms were made up to '99 or so. If the label says "Manufactured in the United Kingdom", which would be likely for a European layout sample, it left IBM's factory in Greenock, Scotland.

Yes. The sticker in the back of the keyboard says "Manufactured in the United Kingdom". I own a genuine IBM Model M manufactured by IBM itself then?

[microsoft windows]

This is almost assuredly a problem of popped rivets, as others have mentioned. Most telling is that all the keys you mentioned are directly adjacent to rivets. The symptoms you describe are typical; broken rivets don't usually interfere very significantly with the mechanical action of the buckling spring, so you'll still feel the snap when you click. But without something hold the membranes firmly, the hammers may not bridge the membrane.

In any case, everyone else's advice in this thread is sound. Your logical choice of action is: buy brand new Unicomp, or attempt a bolt mod.

You don't  need to  do  a full  bolt mod though. I bet if  you even replace a couple of the  broken  rivets, the  keyboard will work much  better.

[ch_123]

I'm happy to read that. But building date is 1997. It really comes from IBM?

Yes. It would have been made in IBM's plant in the UK. Nonetheless, there is some question over just how much was made locally. If you open your keyboard, you will more than likely see Lexmark markings on the electronics for example.

The problems you have sound like they could be membrane failure. I think the nut/bolt mod has been discussed before... in order to fix the membrane, you need to do this mod, but also repair the dead traces with a conductive gel pen.

EDIT: Seeing some posts before mine... Try replacing the few dead rivets first before replacing all the others I guess. Might save you some time if there is actually nothing wrong with the membrane.

[Winrar]

Hi.

We've opened the keyboard and there are no broken rivets in it.

Next step would be cutting the rivets to reach the PCB, but that's serious as it could mean killing the keyboard.

I work in another city and I'm using the keyboard just for a day of two every 3 weeks or so. The keyboard is in a wet region near the sea and my dad says that maybe there is mold covering parts of the PCB.

Any other ideas? What could be the problem if there are no broken rivets?

[jpc]

I have seen an M with some keys that did not work, mostly near the bottom row of typewriter keys. Most of these keys would never report a keypress, though one in particular (the left Alt key) was always reporting a keypress and would not report a key release. (The physical keys all moved up and down and clicked fine.)

After removing the rivets and disassembling everything, the membranes were sticky. My guess is that this board suffered a drink spill. Washing the membranes with soap and warm water fixed it. You need to do the full bolt mod to access the membranes.

[ch_123]

It's almost certainly a membrane issue at this stage. You could try removing the controller and seeing if there is anything wrong with it.

Oh, out of curiosity, does the chip on the controller board (well, the largest chip) say Lexmark on it?

[Winrar]

It's almost certainly a membrane issue at this stage. You could try removing the controller and seeing if there is anything wrong with it.

Oh, out of curiosity, does the chip on the controller board (well, the largest chip) say Lexmark on it?

That membrane issue thing doesn't sound good. If it is broken, how can I fix it?

About the Lexmark marking, I don't know. I haven't seen it. My dad was taking apart the keyboard and I was just talking to him in the phone.

I'll go home next week. I'll look for Lexmark signs on the electronics.

[Winrar]

A guy that sold me a Model M has offered me two mechanical keyboards.

One of them is a Model M exactly like mine. The other is a Lexmark keyboard that he says is exactly like the IBM Model M.

Did Lexmark sell Model Ms under his own brand? Is it a regular Model M? Should I buy it?

[ch_123]

Fixing the membrane itself is easy, but you just have to break open the rivets and then replace them with nuts and bolts.

And yes - Lexmark did make Model Ms under their own branding.

[Winrar]

Fixing the membrane itself is easy, but you just have to break open the rivets and then replace them with nuts and bolts.

Ok. Good to read that. What should I do to fix it? Cleaning? Conductive pen?

And yes - Lexmark did make Model Ms under their own branding.

Fine. I'll get two new keyboards then.

[ch_123]

It depends on what has actually gone wrong in there. I'd advise getting a silver conductive gel pen (you can get them off eBay from Taiwan for about €10-15) and a multimeter. Find the trace on the membrane where the dead keys are located along, and then use the multimeter to find problems and then use the gel pen to repair it.

If you want more detailed pointers, give me a shout if you open it.

[Winrar]

Well. I finally came home and got my hands on the keyboard.

First, there IS indeed a broken rivet, the bottom left corner one. None of the other rivets seems broken or loose.

Second, bad news. Now there are failing keys all over the keyboard, even in the upper rows (backspace doesn't work now for example).

But there is also weird stuff. The down arrow key, which was one of the few non working keys 2 weeks ago now works perfectly. The upper arrow is acting funny: if the keyboard is standing like normal (in horizontal position) it doesn't work, but if I put the keyboard in vertical position and upside down (arrow keys in the top and F keys in the bottom), then the up arrow keys DOES work. Tested this several times in the GRUB menu.

Does this tell something about the issue my keyboard suffers? Is it now membrane or rivets?

BTW, there are Lexmark markings in the huge chip where the status leds sit.

[Winrar]

We are going to cut the rivets in order to see if the membrane has mold. Then we'll clean it and try to put the keyboard together. We are going to use glue (strong professional glue) instead of nuts and bolts. We'll see...

If it goes wrong, then I'll have some spare keys, keycaps and springs. I have one more M and 3 of them are on their way home.

Besides, I'm going to order a Unicomp with USB and such stuff.

A question about Unicomp: My other M has both legs missing? Do the legs in Unicomps fit Model Ms? I guess I could order a bunch of spare legs if they fit.

[itlnstln]

Gah.  I thought you were tim4wmail for a minute (old member).

[Winrar]

Gah.  I thought you were tim4wmail for a minute (old member).

lolwut?

[itlnstln]

Tim had the same avatar (Japanese Brother BS unit).  He was one of our more "colorful" members for awhile.

[ch_123]

We are going to cut the rivets in order to see if the membrane has mold. Then we'll clean it and try to put the keyboard together. We are going to use glue (strong professional glue) instead of nuts and bolts. We'll see...

This has been tried before with less than desirable results. Even if you apply the glue in such a way that it doesn't melt the membrane, it doesn't really hold the thing together strongly enough.

[ch_123]

Tim had the same avatar (Japanese Brother BS unit).  He was one of our more "colorful" members for awhile.

Colourful in that he seemed genuinely convinced that all non-Christians would burn in hell.

The glue works.

Maybe if a small number of rivets need to be glued as is the case in that picture. Some guy did a comparison of a full glue-up compared with a full bolt mod. Gluing the entire keyboard gave unsatisfactory key feel.

[Winrar]

Well, obviously I'd like bolt mod better than glueing the keyboard, but my father, and not me, is doing the job and says that bolt mod would be too much work. He says that we will glue it back again if it brokes.

[Winrar]

We've completely taken apart the keyboard, and I finally convinced my dad to use bolts and nuts instead of glue. We have yet to find 2mm bolts, but there is no hurry.

The grey sheet of that cotton looking material that sits between the plastic and the triple PCB was a bit wet just under the two holes that hold the metal bar of the space bar, and one of the springs has a bit of rust.

There were also a dozen of broken rivets, but problem seems to be in the upper PCB (I call "PCB" to the transparent circuits). There are ten or twelve "lanes" in the bit of that PCB that is placed under the chip that holds the leds. At least 4 of these lanes seem to be lacking the silver shiny material present in the others. This explains why some keys worked when the keyboard was inclinated (they made better contact, I guess).

We are taking the PCB to a guy who works with electronics and see if he can fix it. After that, bolt mod.

[Computer-Lab in Basement]

Good luck.  I hope you can fix your Model M, for they are indeed superior to most other keyboards I have ever used.  True love to be going through all this trouble for your beloved Model M.  I would probably do the same thing.

[Winrar]

Good luck.  I hope you can fix your Model M, for they are indeed superior to most other keyboards I have ever used.  True love to be going through all this trouble for your beloved Model M.  I would probably do the same thing.

Thanks. The upper PCB looked burnt. I took pics with my low resultion cell phone. I'll post them tomorrow. We sanded it and tested it with a multimeter and there are no broken sections.

Now we will reassemble it. This will happen in two or three weeks, as I have to go to workplace in a couple of hours. If it doesn't work, maybe the problem lies in the big chip or in the contact between it and the transparent PCB.

[ch_123]

We've completely taken apart the keyboard, and I finally convinced my dad to use bolts and nuts instead of glue. We have yet to find 2mm bolts, but there is no hurry.

The grey sheet of that cotton looking material that sits between the plastic and the triple PCB was a bit wet just under the two holes that hold the metal bar of the space bar, and one of the springs has a bit of rust.

There were also a dozen of broken rivets, but problem seems to be in the upper PCB (I call "PCB" to the transparent circuits). There are ten or twelve "lanes" in the bit of that PCB that is placed under the chip that holds the leds. At least 4 of these lanes seem to be lacking the silver shiny material present in the others. This explains why some keys worked when the keyboard was inclinated (they made better contact, I guess).

We are taking the PCB to a guy who works with electronics and see if he can fix it. After that, bolt mod.

Repairing a membrane isn't really a specialized task. You can get a conductive silver gel pen off eBay relatively cheaply and fill in dead traces. The only piece of electronic equipment you really need is some sort of multimeter (even a basic one) to determine all the points of failure in the traces.

[Winrar]

Here are some pics I took yesterday. Cell phone pics. Sorry for the poor quality:

This is what we thought to be the problem. There is burnt and apparently missing sections in the upper transparent PCB. I think you call this the membrane:







We sanded the part of the membrane that joins the chip on the top right part of the keyboard and tested it with a multimeter. No errors.

This is the cotton like material sheet that sits between the black plastic plate and the triple membrane. See the wet spots under the clips that hold the space bar steel bar:



Lexmark markings on the chip. Someone was curious about them. Here they are:



"New" Model M. The guy that sold it to me in eBay says he has at least two more. I'm waiting for him to contact me to get them:



Now I got a 122 key (123 actually, as it is a spanish layout keyboard) terminal Model F. Also off eBay. The vendor says that he has more keyboards. I'll try to get them for a good price.

I'm also definitely getting a Unicomp. Both of my Model Ms have broken or missing legs. Are Unicomp's legs like Model M's legs? Can I order spare legs for my Ms from Unicomp?

I'll keep you updated when we reassemble the keyboard in two or three weeks. Let's pray it works.

Regards.

[Surly73]

Here are some pics I took yesterday. Cell phone pics. Sorry for the poor quality:

This is what we thought to be the problem. There is burnt and apparently missing sections in the upper transparent PCB. I think you call this the membrane:

It's hard to be certain from the pictures I see there, but I'm not sure that's "burnt".  You mentioned finding signs of a drink spill in an earlier post - I think that might be all it is that you see.  Combine that with a popped rivet and you may have found your problem(s).  Perhaps try cleaning the membranes with distilled water followed by 50:50 distilled water and isopropyl alcohol (to speed drying in nooks and crannies).  Dry thoroughly and reassemble.  I guess you have a good source for other Model Ms so saving this one may not be a big concern for you.  Generally you want to try to keep it simple - don't start sanding membranes if all they needed was water.  

[ch_123]

Some degree of erosion is common and not particularly bad on a membrane. You really need to do some testing to determine where the fail point is.

[Winrar]

It's hard to be certain from the pictures I see there, but I'm not sure that's "burnt".  You mentioned finding signs of a drink spill in an earlier post - I think that might be all it is that you see.  Combine that with a popped rivet and you may have found your problem(s).  Perhaps try cleaning the membranes with distilled water followed by 50:50 distilled water and isopropyl alcohol (to speed drying in nooks and crannies).  Dry thoroughly and reassemble.  I guess you have a good source for other Model Ms so saving this one may not be a big concern for you.  Generally you want to try to keep it simple - don't start sanding membranes if all they needed was water.  

Ok, then it is  matter of dirt in the membrane plus broken rivets. We'll clean the membrane and bolt mod the rivets.

Besides, this keyboard is special for me. I have been using it for 14 years. I didn't know it was a IBM Model M. I even ignored what IBM Model M was, and I didn't took care of it. Just cleaned keys now and then and treated the keyboard like people treats keyboards (i mean, like ****).

Now I know it is special, and maybe I'm trying to compensate that love deficit. I'll get as many Model Ms as I can, but this one is the one I'd like to keep in good work shape the most.

Talking about cleaning. How do I clean this part of the keyboard?



It looks like a regular cloth. Washing machine?

Some degree of erosion is common and not particularly bad on a membrane. You really need to do some testing to determine where the fail point is.

We tested every lane that looked ugly with a multimeter, and all of them were working. Problem is elsewhere.

Thanks for caring about my keyboard.

[theferenc]

I would NOT throw that in the washing machine. It always just feels like it would disintegrate, which would be bad for you.

Honestly, I don't know how to clean those, or even if it would be necessary to do so. Anyone else want to chime in? I have never even looked at that when I was checking over my keyboards.

[jpc]

You'd probably be OK to hand-wash the rubber mat in warm soapy water. They survive drink spills, water shouldn't hurt. I have not tried this but I wouldn't hesitate to dunk it in water.

[Winrar]

You'd probably be OK to hand-wash the rubber mat in warm soapy water. They survive drink spills, water shouldn't hurt. I have not tried this but I wouldn't hesitate to dunk it in water.

This material looks like cotton. Wouldn't warm water shrink it? That would be no good.

[ch_123]

The rubber mat isnt really crucial, its only a protective layer.

[Surly73]

I also wouldn't use the washing machine.  Hand wash in warm water with a little bit of some kind of gentle soap - maybe a dish detergent or Ivory snow.  Just to be particular you could do a final rinse in distilled water just to be sure that residues of your soap don't cause any long term problems either directly to that piece or to the other components which touch it.  I would pat dry with a towel and then lay flat to air dry.

[Winrar]

That material isn't latex nor any kind of rubber. It is a cloth.

[Winrar]

Wrap it around your head and few times and report back.

It's rubber.

It is something like 200 miles far from where I am sitting, but even from there I can tell you that it is NOT rubber. I've touched it. Not rubber.

[ch_123]

Any ones I've encountered were rubber. But knowing the boys in Greenock and their propensity for subtle differences, the mat is probably made from tartan.