IBM Model M Cable Repair

[edragy]

Just received 2 IBM model M in the mail today, $40 USD incl shipping. As the seller noted the cable is slightly damaged on one of them. If the cable is bumped in a particular way the keyboard stops working for a second or two. Pictures of the damage is attached.



Any ideas on how to fix this would be great.

[tuxsavvy]

Doesn't those keyboards come with detachable coiled cable? rather what is the part number for the keyboard?

If the keyboard has a detachable coiled cable, the simplest solution would be for one to buy replacement cables from clickykeyboards.com:
http://www.clickykeyboards.com/index.cfm/fa/categories.main/parentcat/9417

I am not exact sure on how to fix a semi frayed cable, it looks like as if the sheathe within the cable is gone. It also depends on how bad to the extent of the damage it would be.

When you say you bump the coiled cable in a particular way the keyboard stops working. I would sort of say where the exact location of the photo on the frayed cable would most likely be the one causing the issue. Maybe the ground wire is exposed and when it contacts some other part it may cause interference (which I guess is already what is happening).

Actually on closer look, you can see the blue cable within that semi exposed coiled cable shows the bare wires. That could be the reason that when you bump the cable in a particular way the keyboard stops responding.

[edragy]

Doesn't those keyboards come with detachable coiled cable? rather what is the part number for the keyboard?

If the keyboard has a detachable coiled cable, the simplest solution would be for one to buy replacement cables from clickykeyboards.com:
http://www.clickykeyboards.com/index.cfm/fa/categories.main/parentcat/9417

I am not exact sure on how to fix a semi frayed cable, it looks like as if the sheathe within the cable is gone. It also depends on how bad to the extent of the damage it would be.

When you say you bump the coiled cable in a particular way the keyboard stops working. I would sort of say where the exact location of the photo on the frayed cable would most likely be the one causing the issue. Maybe the ground wire is exposed and when it contacts some other part it may cause interference (which I guess is already what is happening).

Actually on closer look, you can see the blue cable within that semi exposed coiled cable shows the bare wires. That could be the reason that when you bump the cable in a particular way the keyboard stops responding.

No this keyboard does not have a detachable cable. Its part number is 52G9658 which is meant to be made by Lexmark but this one has a regtangular IBM label on it, rather than a Lexmark label. It was one of the first 52G9658 keyboards made in 1993 I believe. The black wire inside the cable has the exposed wire, which causes the keyboard to stop working when it touches the silver stuff in the picture.

[rowdy]

Detachable and attached cables:

http://pckeyboard.com/page/category/Cables

[tuxsavvy]

Doesn't those keyboards come with detachable coiled cable? rather what is the part number for the keyboard?

If the keyboard has a detachable coiled cable, the simplest solution would be for one to buy replacement cables from clickykeyboards.com:
http://www.clickykeyboards.com/index.cfm/fa/categories.main/parentcat/9417

I am not exact sure on how to fix a semi frayed cable, it looks like as if the sheathe within the cable is gone. It also depends on how bad to the extent of the damage it would be.

When you say you bump the coiled cable in a particular way the keyboard stops working. I would sort of say where the exact location of the photo on the frayed cable would most likely be the one causing the issue. Maybe the ground wire is exposed and when it contacts some other part it may cause interference (which I guess is already what is happening).

Actually on closer look, you can see the blue cable within that semi exposed coiled cable shows the bare wires. That could be the reason that when you bump the cable in a particular way the keyboard stops responding.

No this keyboard does not have a detachable cable. Its part number is 52G9658 which is meant to be made by Lexmark but this one has a regtangular IBM label on it, rather than a Lexmark label. It was one of the first 52G9658 keyboards made in 1993 I believe. The black wire inside the cable has the exposed wire, which causes the keyboard to stop working when it touches the silver stuff in the picture.

From the close-up photo to me it seems like the leftmost wire (to the left of black wire even) seems exposed. Unless if that is part of the black wire I was under the impression it was the blue wire that was exposed.

I believe that silver stuff is the sheathe. It is mainly used to prevent wires from being subjected to inteference. It might even be grouding, I am not sure.

There might be other ways to rectify the issue even if the cable is not detachable. I do personally think such attribute of non-detachable cables are a bit of a shame but.. There are other ways I guess one could rectify such as to maybe make their own cables to suit the scenario. I am not an expert on this but surely there has to be other ways. Fixing up a frayed cable seems more difficult to me than replacing the entire cable. Even if you managed to fix up that area, somewhere/sometime down the track something else intermittently works. What then?  Better to replace the whole thing (cable) in my opinion instead.

[edragy]

Doesn't those keyboards come with detachable coiled cable? rather what is the part number for the keyboard?

If the keyboard has a detachable coiled cable, the simplest solution would be for one to buy replacement cables from clickykeyboards.com:
http://www.clickykeyboards.com/index.cfm/fa/categories.main/parentcat/9417

I am not exact sure on how to fix a semi frayed cable, it looks like as if the sheathe within the cable is gone. It also depends on how bad to the extent of the damage it would be.

When you say you bump the coiled cable in a particular way the keyboard stops working. I would sort of say where the exact location of the photo on the frayed cable would most likely be the one causing the issue. Maybe the ground wire is exposed and when it contacts some other part it may cause interference (which I guess is already what is happening).

Actually on closer look, you can see the blue cable within that semi exposed coiled cable shows the bare wires. That could be the reason that when you bump the cable in a particular way the keyboard stops responding.

No this keyboard does not have a detachable cable. Its part number is 52G9658 which is meant to be made by Lexmark but this one has a regtangular IBM label on it, rather than a Lexmark label. It was one of the first 52G9658 keyboards made in 1993 I believe. The black wire inside the cable has the exposed wire, which causes the keyboard to stop working when it touches the silver stuff in the picture.

From the close-up photo to me it seems like the leftmost wire (to the left of black wire even) seems exposed. Unless if that is part of the black wire I was under the impression it was the blue wire that was exposed.

I believe that silver stuff is the sheathe. It is mainly used to prevent wires from being subjected to inteference. It might even be grouding, I am not sure.

There might be other ways to rectify the issue even if the cable is not detachable. I do personally think such attribute of non-detachable cables are a bit of a shame but.. There are other ways I guess one could rectify such as to maybe make their own cables to suit the scenario. I am not an expert on this but surely there has to be other ways. Fixing up a frayed cable seems more difficult to me than replacing the entire cable. Even if you managed to fix up that area, somewhere/sometime down the track something else intermittently works. What then?  Better to replace the whole thing (cable) in my opinion instead.

I have another IBM model M from 1995 that is really dirty and is missing 15 or so keycaps with a  PS/2 cable on it, how hard would it be (if possible) to swap the cables over?

[tuxsavvy]

Doesn't those keyboards come with detachable coiled cable? rather what is the part number for the keyboard?

If the keyboard has a detachable coiled cable, the simplest solution would be for one to buy replacement cables from clickykeyboards.com:
http://www.clickykeyboards.com/index.cfm/fa/categories.main/parentcat/9417

I am not exact sure on how to fix a semi frayed cable, it looks like as if the sheathe within the cable is gone. It also depends on how bad to the extent of the damage it would be.

When you say you bump the coiled cable in a particular way the keyboard stops working. I would sort of say where the exact location of the photo on the frayed cable would most likely be the one causing the issue. Maybe the ground wire is exposed and when it contacts some other part it may cause interference (which I guess is already what is happening).

Actually on closer look, you can see the blue cable within that semi exposed coiled cable shows the bare wires. That could be the reason that when you bump the cable in a particular way the keyboard stops responding.

No this keyboard does not have a detachable cable. Its part number is 52G9658 which is meant to be made by Lexmark but this one has a regtangular IBM label on it, rather than a Lexmark label. It was one of the first 52G9658 keyboards made in 1993 I believe. The black wire inside the cable has the exposed wire, which causes the keyboard to stop working when it touches the silver stuff in the picture.

From the close-up photo to me it seems like the leftmost wire (to the left of black wire even) seems exposed. Unless if that is part of the black wire I was under the impression it was the blue wire that was exposed.

I believe that silver stuff is the sheathe. It is mainly used to prevent wires from being subjected to inteference. It might even be grouding, I am not sure.

There might be other ways to rectify the issue even if the cable is not detachable. I do personally think such attribute of non-detachable cables are a bit of a shame but.. There are other ways I guess one could rectify such as to maybe make their own cables to suit the scenario. I am not an expert on this but surely there has to be other ways. Fixing up a frayed cable seems more difficult to me than replacing the entire cable. Even if you managed to fix up that area, somewhere/sometime down the track something else intermittently works. What then?  Better to replace the whole thing (cable) in my opinion instead.

I have another IBM model M from 1995 that is really dirty and is missing 15 or so keycaps with a  PS/2 cable on it, how hard would it be (if possible) to swap the cables over?

I am not sure to be really frank. If you post up some photos of both keyboards with their PCB along with the places where the cables are attached you maybe able to get some further help on this.

In theory, as long as your Model M communicates as a AT sort of keyboard, AT to PS/2 conversion should not be hard. That said I really do not have a clue otherwise.

[fohat.digs]

If the cable is wrecked at the plug, that is going to be very difficult.

The tear in the sheathing is easier. If it were mine, I would use my smallest sharpest scissors to trim away the frayed area in a clean cut and expose the inner wires for a small distance (maybe the width of a finger).

I would gently pull out into a loop a small section to see if there was any exposure. You will probably find at least one nick in some of the colored insulation, and you can insulate that with a small piece of electrical tape. Then protect the whole area with tape. White electrical tape makes repairs like this look a lot nicer.

[berserkfan]

Fohat's suggestion is good, but it requires skill, and moreover coiled cables are damn hard to handle. Cleaning them is hard enough; I've found that repairing them is a PITA.

On most old keyboards, the coiled cable gets nasty and sticky after a while. I don't think your coiled cable looks very nice and it probably feels terrible, am I right?

May I suggest you take advantage of this problem to discard the cable entirely? Why not open up the entire keyboard, clean the inside out, pull the coiled cable from the belkin and substitute in another cable? Maybe do a USB mod while you're at it.

[wcass]

I have another IBM model M from 1995 that is really dirty and is missing 15 or so keycaps with a  PS/2 cable on it, how hard would it be (if possible) to swap the cables over?

it should be pretty easy. if the '95 cable is removable then you will need to swap the controller too.

[edragy]

I have another IBM model M from 1995 that is really dirty and is missing 15 or so keycaps with a  PS/2 cable on it, how hard would it be (if possible) to swap the cables over?

it should be pretty easy. if the '95 cable is removable then you will need to swap the controller too.

Neither of the keyboards in question have removable cables. Inside the keyboard does the cable plug into the controller or is it soldered on? Also what is the correct tool to open a Model M?

[fohat.digs]

I have another IBM model M from 1995 that is really dirty and is missing 15 or so keycaps with a  PS/2 cable on it, how hard would it be (if possible) to swap the cables over?

it should be pretty easy. if the '95 cable is removable then you will need to swap the controller too.

Neither of the keyboards in question have removable cables. Inside the keyboard does the cable plug into the controller or is it soldered on? Also what is the correct tool to open a Model M?

I am pretty sure that there is an internal plug for the cable, but don't trust it to pin out exactly the same.

You will need a 7/32" nut driver or thin-walled socket. 5.5mm will substitute perfectly.

[Aer Fixus]

An alternative solution to swapping cables is to swap keycaps. They are universal to all buckling spring boards*, so if the other keyboard works and has no damaged springs, and you are not attached to the one with the broken cable, this might be a better alternative.

*Edit: I have been corrected. The keycaps are not universal to all buckling spring keyboards. They are compatible between most buckling spring keyboards. The exception is the Model M2 and a somewhat-obscure ALPS format used in the Sega Teradrive.
This should not be a problem in this specific instance.

[rowdy]

I made my own replacement cable (someone had inconveniently trimmed the old cable off with a pair of wire cutters).

[0100010]

The cable that Unicomp sells on their site would work - the 'attached' version.

[rowdy]

The cable that Unicomp sells on their site would work - the 'attached' version.

Show Image

I was considering this, but ended up making my own by mainly salvaging a cable from another PS/2 keyboard and soldering the connector that was still in my Model M.  Worked fine :)

[Elrick]

I was considering this, but ended up making my own by mainly salvaging a cable from another PS/2 keyboard and soldering the connector that was still in my Model M.  Worked fine

That's it, always ghetto-ize the cable to make it work no matter what.  That's what we call Aussie-ingenuity, keep it up bud  .  Proud how a fellow convict shows the world how it's done, in the land down-under.

[rowdy]

I was considering this, but ended up making my own by mainly salvaging a cable from another PS/2 keyboard and soldering the connector that was still in my Model M.  Worked fine

That's it, always ghetto-ize the cable to make it work no matter what.  That's what we call Aussie-ingenuity, keep it up bud  .  Proud how a fellow convict shows the world how it's done, in the land down-under.

Pictures here for the morbidly curious.

[fohat.digs]

I would not use the word "ghetto"

That looks like solid competent work to me. Good job!

[tuxsavvy]

I would not use the word "ghetto"

That looks like solid competent work to me. Good job!

That attached photo... naked IBM! you dirty dirty ... *kidding*

The cable that Unicomp sells on their site would work - the 'attached' version.

Show Image

There were no photos the last time I visited Unicomp website. Though the photo looks very similar to a photo I found from some French guy who was probably selling his/her Model M. He provided some information (of course all in French though) and a photo that looks similar to the photo you provided.

The bottom line is that the OP has two options:

• Take photos of his/her internal IBM Model M keyboard (obviously the one with the frayed cable) particularly on the actual connector from the PCB to the cable itself. Also take photos from his replacement IBM Model M keyboard, same area of the photo as previously mentioned.
• Do the repairs him/herself without assistance.  ;)

[fohat.digs]

That attached photo... naked IBM! you dirty dirty ... *kidding*

It is a whole lot more than naked.

I need to revise my original stealth thread because this one is 1000% better. Those are USB sockets in the upper left.

[berserkfan]

um, how did you get the purple windows keycap?

Also wondering about your usbs. How did you get them there? I do'nt think you have a thread on how to do it yet.

That attached photo... naked IBM! you dirty dirty ... *kidding*

It is a whole lot more than naked.

I need to revise my original stealth thread because this one is 1000% better. Those are USB sockets in the upper left.

[terran5992]

Tons of electrical tape?

[fohat.digs]

how did you get the purple windows keycap?

Also wondering about your usbs. How did you get them there? I do'nt think you have a thread on how to do it yet.

After the first "stealth" project, I did it again and improved everything. I will rebuild the thread sometime soon.

Windows keys are available in any color from Unicomp. Purple and light blue blend pretty nicely with pebble, bright white, cool gray, or yellow can look good in a pearl field.

The USB port is epoxied in and shouldered with rolled felt padding. It is hard to find one small enough, but there is one made for Apples.