When I was a kid I'd take apart my C64 and other computers, but the keyboard disassembly was always a bit scary because part of it was soldered. It took videos like this to finally get me over that! I have a SX-64 keyboard I need to fix now...
Another here for the graphite approach. This is my favourite way to restore conductivity. Some graphite powder mixed with isopropyl and painted on, left to dry, then wiped off with a q tip. Incredibly effective and I've used it on many keyboards now to restore them to like new.
Tried this with my PET, didn't work. Tried a thin coat of silver epoxy paint stuff, didn't work and actually made things worse. Currently investigating a new approach, to suspend a carbon dot above the PCB and activate it with the old plunger mechanism.
thats overkill. i used a carpenters pencil and "colored" the contact pads on the board and all over the rubber pieces. fixed all my keys i had a issue with
Be thankful it wasn’t replacing the entire cable on a C128D keyboard! I should point out I actually had no idea if the keyboard even worked after all that work. As for plungers, I’ve had the best result with the piece of paper method.
Ha, I can imagine that being tedious... Yes, definitely have to be more careful with those plungers. I'll try to use the paper method next time I think. Rubbing them with IPA was not the best idea although I didn't manage to break a key like that before.
Yes but 98% graphite ..... Staedtler Lumograph 9B for example (Made in germany) ........ give you 11 o 15 Kohms... You also use it for "redraw / revive" the black contacts in the circuit board...
Nice! Keyboard issues are a pain and more to the point fragile due to their age. I have on hand spare plungers, springs and carbon paint. The 128 keyboard is easy to troubleshoot because you can follow the keyboard grid map to rule out problem keys and test repairs before reinstalling the keyboard for testing. I went down a rabbit hole with a 128D keyboard which actually tested out fine but because a couple pins on one of the control port were shorted it actually caused several keys not to work including the RETURN Key. Had I done a full external inspection I would of saw this and saved myself a ton of work. Thing is I am not much into games so the control ports were not on my radar and over the years I have never seen bent pins on a control port so I never looked. That bit me badly and I know better, because inspection is the key to everything you work on before and after the repair.
@@JanBeta Thing is I am not much into games so those ports for me rarely get used. Today I inspect everything even those control ports. Eventually your going to get to them anyway to confirm everything is working as it should.
Great job! I think the same thing has happened to that key that Hey Birt described in his early A500 keyboard repair videos! On his, he found that the keys where there's a metal bar supporting it (eg. Enter key), Commodore put some kind of grease / lubricant into the key and on the bar, and that leaks inside onto the key pad. I am sure that's what the cause is - he found the exact same thing, specifically the resistance change to the surface.
I remember hearing many years ago not to use cleaners (even alcohol) on ST keyboard contacts because it could ruin the conductivity. I only lightly used an eraser (rubber) on a few mylar carbon contacts, which seemed to work fine.
Yes, alcohol seems to be a bit too aggressive to clean the plungers. I'm going to try different methods in the future. Although this was the first time I actually seem to have damaged a key.
This was a useful tip for me as I have a broken key on my 128, the plunger has split which causes the key to get stuck down. I have a later edition flat 128 with a cost reduced board (quite rare apparently) but the keyboard looks to be the same as this one, so I'm off to ebay now to look for a replacement key plunger. Thanks Jan!
I solved my stuck keys due to split plunger by: 1) Swap split plunger with rarely used key. 2) Slightly widening hole in support base (where plunger is inserted) so that it does not stick.
I think they probably used these keyboards starting with the first C128s and up to the last Amigas. My A1200 has the same style plungers at least, although most Amigas used a foil membrane instead of the PCB for the contacts.
I think there have been at least experiments of mounting speakers blasting an annoying high-pitched tinny noise into areas kids like to hang around and ruin. Does not bother adults of course :-)
@@benbaselet2026 There were 3 revisions of the A2000 keyboard, so it really depends on which version you're comparing it with. The one with the rubber cup was the last revision: ua-cam.com/video/cJjZ6QjfmiE/v-deo.html
If you would t have a replacement, what you can do as well, is grind up a lead pencil to dust, and use that to repair the conductive carbon later. You’ll have to use something to pressure fit a tiny layer across it (little flat piece of plastic works best). This lasts surprisingly long, but obviously is still temporary (couple years at best). Nice to see another C128 video though, recently did mine too, enjoy this machine a lot :D
Yes, I heard people using pencils to fix these contacts. I would be a bit sceptical about how long that lasts actually. I'll definitely have to tinker with some different methods and chemicals when I get the chance. :)
@Jan Beta I had this problem several times, mostly with the select and start buttons of gameboys, but also with apple ii and amiga keyboards. I think this is all the same stuff, some conductive paint on rubber or plastic that shortens the contacts on the pcb. What i recommend: Go to Lidl and get yourself a bottle of their pink colored nailpolish remover. Soak a kleenex stick in this and gently (very gently) rub the contacts on the rubber. You will see the kleenex stick will get a bit black, as it seems to do a chemical reaction with the contact paint stuff. Let it dry a few minutes and it should work like new. I tested this with some Mitsumi Amiga 500 key stamps and it also worked.
In case someone is in a pinch with spares, I've had some success fixing conductive strips of MIDI keyboards applying Graphit 33 from Kontakt Chemie with a very small brush. I think that could apply to this type of a keyboard as well.
Nice job! Depending on the kind of contacts, you can sometimes restore conductivity by rubbing them on a piece of paper to actually remove the top layer of carbon. But this only works on the kind of contacts that are solid carbon moulded into the rubber dome or whatever. The cheaper kind just have a thin coating of carbon on the surface of the silicone, so rubbing them on a sheet of paper makes them worse! Those ones definitely need some kind of conductive paint to fix, and even then it's not always permanent. I guess the C128 and Amiga keyboards must use that kind. Speaking of keyboard repairs, I just picked up a couple of IBM Model M boards off eBay for a relative bargain. One was working, but was missing the cable and some key caps (as well as one spring), the other wasn't working, but had the cable and a full set of key caps. I've swapped over the key caps and the cable to the working unit, and it still needs a very thorough clean, but I'm happy to have one working Model M. I think the other might be repairable, as it looked like it had a leaky cap on the controller board, but the cable and key caps might be expensive to replace. Anyway, I love these repair videos. Even the simple ones like this are fun to watch. Keep up the great work!
I've successfully used "Keypad Fix" from Amazon US (don't know if it is available in Europe), to restore conductivity to a couple C128 keys. In the past, I used a homemade paste of graphite and IPA brushed on the key pads to restore a VIC20 keyboard. This was not sufficient to fix the C128 keys, so I've decided to try the commercial "Keypad Fix" , and it worked.
Oh, never tried that. I know that there are several different paints and sprays you can use to restore the conductive layer. I definitely have to try some of those.
I'm 45, can still hear 15kHz whine (and crickets/grasshoppers) which is more annoying now than back in the day - when there were no other screens. ;) Well done!
I always figured that Commodore would have had a killer machine with the 128 if they used an 8088 CPU instead of the Z80, so it would have worked with DOS. There's not a lot of big changes hardware-wise to make that work -- imagine a computer that would be able to play your C64 games natively as well as your MS-DOS games and applications. The graphics and sound capabilities would blow a competing system like the Tandy 1000 out of the water.
Interesting thought. I guess it would really have sold a lot more if Commodore had realized in time that CP/M was nearly dead and DOS was on the rise when they released the 128.
@@JanBeta I agree, it was probably mostly a bad business decision by Commodore to go for CP/M, which was only used in older office environments in the 80s. Everybody was moving towards DOS. But at the time the C128 was developed IBM still had pretty strict licensing conditions on the PC platforms, so it could also be too expensive to go for an 8088 instead of a Z80.
Had the same problem on my 128DCR keyboard - the numpad "0" key in my case... I didn't have Amiga plungers available, though. so I glued a small sliver of tinfoil on the plunger rubber itself - works without a hitch :)
@@JanBeta I was too, that was the reason that I made sure it was a single layer only - that way, the plunger would keep its flexibility and the foil wouldn't scratch at the carbon. I was more worried about the resistivity - as the tin foil is less resistive than the plunger material - basically dead short instead of a few hundred ohms. Then again - I rarely use the numpad, so it'll be good enough for now :)
That was a nice surprise that the Amiga 500 keyboard plungers work with the C128, or at least with Mitsumi keyboard. I remember Robin at "8-bit show and tell" had a video where he had a tablet next to the C64 to display frequencies from programs in basic. Then he mentioned the 15kHz whine. I remember the sharp whine and that it gave me headaches but I have no chance of hearing it now :) Have you tried using silicone with graphite ?
Yes, quite useful that the plungers fit both keyboards. :) I think everybody loses the higher end frequencies of their hearing with age slowly. I could not hear the whine for a while. I think playing in rock bands and being an audio tech didn't help my hearing much... ;D Didn't try silicone with graphite yet. I'll have to test some different methods sometime. Lots of suggestions in the comments. :)
On my A500 I found it was the grease from the metal hoops on large keys that caused the problem. The grease liquifies, leaks inside and damages the conductive rubber. I did quite a bit of testing last year and did not find any coating that worked on the Mitsumi key conductive rubber because of the shape. Interesting that the C128 and Amiga have same contacts!
Yes, I saw your video but didn't remember... Shame on me. That may well be what happened in my case, the C128 RETURN key has one of those metal brackets, too. And I probably made it worse by wiping the contacts with IPA again.
@@JanBeta I was taught a long time ago that alcohol was bad for rubber. I learned more recently that this is only true for a few types of rubber which are commonly used for seals and gaskets. It does not hurt silicone rubber at all.
I hate chores to work on the keyboard cleaning eg all my c64'ers have done 6 or so what a job especially with my old eyes, 49 years already but is now all finished with dust cover or minimal dust cover. Do not want to work on it for some time, some were filthy after a few years dirty and had no love. I could have saved you the work the search for another plunger or key element, will not work with a C64, the Amigas are better suited for that, even once experienced in a gray-gray past. ;)) this is not a criticism, making old computers (or demolishing that is not so difficult) should also take a bit of searching because you have forgotten UA-cam is still a fantastic Tool. Although it doesn't include everything, that's why I love your channel so much and do this to help each other. I have always been a Hardware man used to pull things apart did not always end well usually :) but I learned a lot from that. X without tongue :))
Nice find that the plungers are identical to the Amiga Mitsumi plungers. I designed and printed a replacement plunger for an A500 (just the plastic part) using my 3D printer when I didn't have any salvaged plungers on hand. It worked quite well so it's good to know it fits the C128 as well. I put it on Thingiverse: www.thingiverse.com/thing:3910131
I'd just use a small piece of aluminium tape (used for thermal protection while using hot air) and stick it on the bottom of the plunger. It's conductive. I'm using it often lately while repairing Sega Mega Drive controllers.
That's why I'm not a fan of these sort of mechanisms for a keyboard. One little slip up and you lose some keys and then you have to take the keyboard apart (insert obvious hatred of so many screws here) and then you have to get the right amount of conductive material or as you did a replacement part. That aside, at least you didn't have to do that to the entire keyboard. I've never seen it in person but is it actually possible to completely rub away the material on the plungers that easily though, I feel that as people describe it that it's as simple as alcohol rubbing can easily undo it so it's not even worth cleanin? Keep it up Jan! Also, great hair, do what you want with it.
Yes, quite a tedious process. But at least it worked. I didn't think that it was so easy to wipe away the whole conductive layer but this fault proves me wrong I guess. Good thing I had several options to look for spare parts. :)
Ive repaired conductive rubber contacts in remote controls before by gluing a tiny piece of aluminium foil to the rubber pad(s). Its guaranteed to work. I don't have any conductive silver paint and it is expensive.
It makes perfect sense that the keys of the Amiga and C128 would be the same because they were ALWAYS looking to cut costs at Commodore. So using the same keyboard parts makes perfect, economic sense. You should have had a bit more faith in that :).
Haha, makes sense. To be fair to Commodore, the Amiga keyboard is a different construction apart from using the same plungers. And the same mechanism most likely was used for other Mitsumi keyboards as well. ;)
All you need to do to make C128 keyboards work again is give a light scuff on the conductive pad on the plunger, with a fine fingernail file or emery board, only *just* enough to get rid of the surface shine. On the PCB side, scrub with a pencil eraser. You won't damage the carbon, it ain't THAT thin. 😛 The clean everything with alcohol.
Always a relaxing video. Thanks. Have you tried "Bare conductive Electric Paint" It goes on like water based paint so can be helpful for weird tracks and funny shaped pads... Yes...
Hmm...I would never think to clean the rubber pads with IPA. A common trick is to use a piece of paper and give it a slight rub. that's worked very well for me in the past.
Yes, it would have worked. There are a number of different lacquers and paints that can be used. I didn't have any of that but the spare A500 keyboard so I figured this would be the most reasonable fix in my case. :)
Hi Jan great video on keyboard repair for the C128. I do have a question. My 128 needs the F1 & F7 plungers replaced. I have heard those use different parts than the normal keys. do you know if this is the case? or can I just use parts from an old Amiga keyboard like you did here? Thanks!
On my particular one all the plungers are the same but unfortunately there are different versions of the keyboards, some have plungers that don’t match the Amiga ones.
@@JanBeta I just want to give you an update to pass onto your viewers. I checked the top row of keys on my 128, which includes ESC, TAB, and all of the function keys, those all use different plungers than the normal keys on the lower part of the keyboard. so I would say that for letter keys & other ones on the lower keyboard, it's probably safe to use the Amiga plungers, but, for the upper keys probably not but I really can't say for sure. I may go ahead & experiment to see if Amiga plungers will do the trick. I'll check back with you then.
I can hear CRT whine even when there's no CRT around me... I do remember going into TV shops as a kid and being hit by a giant sound from all the TVs. It wasn't very nice.
20:17 - Sadly, I learned this the hard way. A while ago (jeez, it was _seven_ years ago 😲), I cleaned a keyboard and scrubbed a little too hard on the end of the ribbon-cable and the conductive traces came right off. 🤦 I "recently" (almost two months ago) ordered a syringe of wire-glue from eBay and am currently waiting for it to arrive from China so that I can try to fix it. 😕
Done cleaning of lot commodore 64 or 128 keyboard cleaning, always cleaning plungers with IPA, never had issues like this. Probably plunger was already damaged.
Interesting idea, it would probably work. Although ideally, you still don’t want to take apart and reassemble your hardware every other day anyway... ;)
I did watch another youtube that did say that we should not put "heatsink" on c64/c128 chips since commodore did put thermopast on the back of the RFC sheild that works as a heatsink. So whats is your opinion on this. ?
In my experience, the metal shield often doesn't make good contact to the chips and doesn't work very well as a heatsink. I prefer to put heatsinks directly on the ICs. The RF shields are pretty useless otherwise, too, nowadays. The frequencies emitted by the old machines are not interfering with any modern electronics as far as I know.
I thought you had a frame meister or something like that. I seriously need to get a retro tink. My stupid upscaler dynamically stretches to 16:9. So playing side scrollers like sam's journey makes me a little dizzy. Static images actually look pretty good though. But yeah I'd prefer the 4:3 aspect ratio.
"Some young people can hear the CRT whine" I'm glad I can be considered young. I'm one of those bloody annoying complainers.. "oi Jan! my head hurts now!" Another fantastic Video Jan, keep it up.
slt jan me when I repair old keyboard or the carbon contacts are worn by time I pass a silver-based liquid which dries after a few minutes which used to repair the defrosting of the rear windows of cars I have never found problems with this method cordially
I am sure you have answered this a million times but why is the manufacturer name on the lcd you use for testing your retro computers censored and why is the crt to your left displaying the same manufacturer name in the wild unhindered ?
I had the same problem and fixed it with the rubber pad from another key. Here's my video from about a month ago: ua-cam.com/video/HXpSB494Vhg/v-deo.html
i have two c128 keyboard and two case and a defect supply if you want it i give it to you i'm from belgium i only collect c64 and amiga stuff but not all best regard Guntattoo
@@JanBeta The aluminium foil stuff you wrap food in is so soft and thin it would be worn away long before your pcb got any visible markings. It's a known way to fix old remotes...
When I was a kid I'd take apart my C64 and other computers, but the keyboard disassembly was always a bit scary because part of it was soldered. It took videos like this to finally get me over that! I have a SX-64 keyboard I need to fix now...
I'm more scared of the screws and the mechanics than of the soldering these days but it was the same for me back in the day. :)
Another here for the graphite approach. This is my favourite way to restore conductivity. Some graphite powder mixed with isopropyl and painted on, left to dry, then wiped off with a q tip. Incredibly effective and I've used it on many keyboards now to restore them to like new.
Yes, that is a good idea. I'll have to try some different methods and also some of the pre-made chemicals/lacquers sometime. :)
Tried this with my PET, didn't work.
Tried a thin coat of silver epoxy paint stuff, didn't work and actually made things worse.
Currently investigating a new approach, to suspend a carbon dot above the PCB and activate it with the old plunger mechanism.
thats overkill. i used a carpenters pencil and "colored" the contact pads on the board and all over the rubber pieces. fixed all my keys i had a issue with
Be thankful it wasn’t replacing the entire cable on a C128D keyboard!
I should point out I actually had no idea if the keyboard even worked after all that work.
As for plungers, I’ve had the best result with the piece of paper method.
Ha, I can imagine that being tedious... Yes, definitely have to be more careful with those plungers. I'll try to use the paper method next time I think. Rubbing them with IPA was not the best idea although I didn't manage to break a key like that before.
Graphite from a pencil works well in a pinch for restoring contact. Just color the contact in and test!
Great video!!!
Yes, good idea! I would consider that a great quick fix but would be worried a bit about how long that actually lasts. :)
Yes but 98% graphite ..... Staedtler Lumograph 9B for example (Made in germany) ........ give you 11 o 15 Kohms...
You also use it for "redraw / revive" the black contacts in the circuit board...
Really like the way you've put the video into different parts on the video progress part, or whatever it's called. That's extremely rare to see.
Nice! Keyboard issues are a pain and more to the point fragile due to their age. I have on hand spare plungers, springs and carbon paint. The 128 keyboard is easy to troubleshoot because you can follow the keyboard grid map to rule out problem keys and test repairs before reinstalling the keyboard for testing. I went down a rabbit hole with a 128D keyboard which actually tested out fine but because a couple pins on one of the control port were shorted it actually caused several keys not to work including the RETURN Key. Had I done a full external inspection I would of saw this and saved myself a ton of work. Thing is I am not much into games so the control ports were not on my radar and over the years I have never seen bent pins on a control port so I never looked. That bit me badly and I know better, because inspection is the key to everything you work on before and after the repair.
Oh, I would not have suspected the control ports either I think. Interesting fault. Probably would have noticed that testing games. :)
@@JanBeta Thing is I am not much into games so those ports for me rarely get used. Today I inspect everything even those control ports. Eventually your going to get to them anyway to confirm everything is working as it should.
I'm 39, can still hear the 15khz whine. But I still prefer crt :) Nice hint, useing plungers from Amiga keyboard, thank you for another great video :)
Nice, so you officially qualify as young. At least judging by your hearing. :D
Great job! I think the same thing has happened to that key that Hey Birt described in his early A500 keyboard repair videos! On his, he found that the keys where there's a metal bar supporting it (eg. Enter key), Commodore put some kind of grease / lubricant into the key and on the bar, and that leaks inside onto the key pad. I am sure that's what the cause is - he found the exact same thing, specifically the resistance change to the surface.
Thanks! Yes, that may well be what happened. Probably made worse by me wiping the plunger with IPA. :)
I remember hearing many years ago not to use cleaners (even alcohol) on ST keyboard contacts because it could ruin the conductivity. I only lightly used an eraser (rubber) on a few mylar carbon contacts, which seemed to work fine.
Yes, alcohol seems to be a bit too aggressive to clean the plungers. I'm going to try different methods in the future. Although this was the first time I actually seem to have damaged a key.
This was a useful tip for me as I have a broken key on my 128, the plunger has split which causes the key to get stuck down. I have a later edition flat 128 with a cost reduced board (quite rare apparently) but the keyboard looks to be the same as this one, so I'm off to ebay now to look for a replacement key plunger. Thanks Jan!
I solved my stuck keys due to split plunger by: 1) Swap split plunger with rarely used key. 2) Slightly widening hole in support base (where plunger is inserted) so that it does not stick.
I think they probably used these keyboards starting with the first C128s and up to the last Amigas. My A1200 has the same style plungers at least, although most Amigas used a foil membrane instead of the PCB for the contacts.
I love driving my kids crazy with CRT hiss.
I think there have been at least experiments of mounting speakers blasting an annoying high-pitched tinny noise into areas kids like to hang around and ruin. Does not bother adults of course :-)
Haha, yes, my kid always complains about it, too. :D
Jan Beta: 10 screws and 6 solder joints - "oh no, all these screws!"
Me: 100 screws and one solder joint - "omg no, soldering!"
😅
I always used a white gummy eraser on the carbon contact, never had to replace a single key stem. Good vids!
That's probably a better approach than using IPA and Q-tips. :)
There are also (lots of) Mitsumi-made PC keyboards with the same plungers.
The KPQ series which also have those rubber cups which can be used to mod the A500 keyboards to be more like the A2000 ones BTW.
@@csabasanta5696 Oh? Now there's a tip! The A2000 keyboard was godlike at the time when I was comparing my A500 or later 1200 with my buddy's 2000.
@@benbaselet2026 There were 3 revisions of the A2000 keyboard, so it really depends on which version you're comparing it with. The one with the rubber cup was the last revision: ua-cam.com/video/cJjZ6QjfmiE/v-deo.html
Oh, makes sense. Thanks for pointing that out!
If you would t have a replacement, what you can do as well, is grind up a lead pencil to dust, and use that to repair the conductive carbon later. You’ll have to use something to pressure fit a tiny layer across it (little flat piece of plastic works best). This lasts surprisingly long, but obviously is still temporary (couple years at best). Nice to see another C128 video though, recently did mine too, enjoy this machine a lot :D
Yes, I heard people using pencils to fix these contacts. I would be a bit sceptical about how long that lasts actually. I'll definitely have to tinker with some different methods and chemicals when I get the chance. :)
@Jan Beta I had this problem several times, mostly with the select and start buttons of gameboys, but also with apple ii and amiga keyboards. I think this is all the same stuff, some conductive paint on rubber or plastic that shortens the contacts on the pcb. What i recommend: Go to Lidl and get yourself a bottle of their pink colored nailpolish remover. Soak a kleenex stick in this and gently (very gently) rub the contacts on the rubber. You will see the kleenex stick will get a bit black, as it seems to do a chemical reaction with the contact paint stuff. Let it dry a few minutes and it should work like new. I tested this with some Mitsumi Amiga 500 key stamps and it also worked.
Oh, interesting approach. Thanks for sharing! I'll have to try some methods and compare sometime. :)
In case someone is in a pinch with spares, I've had some success fixing conductive strips of MIDI keyboards applying Graphit 33 from Kontakt Chemie with a very small brush. I think that could apply to this type of a keyboard as well.
Yes, that is definitely a good way to do it. I'll have to try some different chemicals/lacquers and methods sometime. :)
Nice job!
Depending on the kind of contacts, you can sometimes restore conductivity by rubbing them on a piece of paper to actually remove the top layer of carbon. But this only works on the kind of contacts that are solid carbon moulded into the rubber dome or whatever. The cheaper kind just have a thin coating of carbon on the surface of the silicone, so rubbing them on a sheet of paper makes them worse! Those ones definitely need some kind of conductive paint to fix, and even then it's not always permanent. I guess the C128 and Amiga keyboards must use that kind.
Speaking of keyboard repairs, I just picked up a couple of IBM Model M boards off eBay for a relative bargain. One was working, but was missing the cable and some key caps (as well as one spring), the other wasn't working, but had the cable and a full set of key caps. I've swapped over the key caps and the cable to the working unit, and it still needs a very thorough clean, but I'm happy to have one working Model M. I think the other might be repairable, as it looked like it had a leaky cap on the controller board, but the cable and key caps might be expensive to replace.
Anyway, I love these repair videos. Even the simple ones like this are fun to watch. Keep up the great work!
You could just use the cable from a crappy cheap PS/2 keyboard or an old USB cable. Maybe you could 3D print or resin cast replacement keycaps?
Excellent! I have a bad plunger in a C128 and I had not checked out the A500 plungers. Maybe now I can fix my Broken function key!
Hope it works! :)
Good. I try it next weekend😊
I've successfully used "Keypad Fix" from Amazon US (don't know if it is available in Europe), to restore conductivity to a couple C128 keys. In the past, I used a homemade paste of graphite and IPA brushed on the key pads to restore a VIC20 keyboard. This was not sufficient to fix the C128 keys, so I've decided to try the commercial "Keypad Fix" , and it worked.
Oh, never tried that. I know that there are several different paints and sprays you can use to restore the conductive layer. I definitely have to try some of those.
I'm 45, can still hear 15kHz whine (and crickets/grasshoppers) which is more annoying now than back in the day - when there were no other screens. ;)
Well done!
You officially qualify as young then! ;)
At least regarding hearing. :D
Damn. I really wanted to see you trial a conductive paint repair.
I don’t have any of that stuff so this was the most reasonable way to fix it in my case.
That stuff is expensive and not worth the cost just for one key. If you were repairing a lot of the keys, you'd buy it.
Those young people with their good hearing! Loud music stopped me being annoyed by high frequency hiss years ago :D Good keyboard save. Cheers
Same here, I played in rock bands for years, guess that didn't make my hearing any better. :D
I'll bet you had fun though :-)
I always figured that Commodore would have had a killer machine with the 128 if they used an 8088 CPU instead of the Z80, so it would have worked with DOS. There's not a lot of big changes hardware-wise to make that work -- imagine a computer that would be able to play your C64 games natively as well as your MS-DOS games and applications. The graphics and sound capabilities would blow a competing system like the Tandy 1000 out of the water.
Interesting thought. I guess it would really have sold a lot more if Commodore had realized in time that CP/M was nearly dead and DOS was on the rise when they released the 128.
@@JanBeta I agree, it was probably mostly a bad business decision by Commodore to go for CP/M, which was only used in older office environments in the 80s. Everybody was moving towards DOS. But at the time the C128 was developed IBM still had pretty strict licensing conditions on the PC platforms, so it could also be too expensive to go for an 8088 instead of a Z80.
Love your vids Jan.
Thank you! Many more still to come. :)
Tks for the morning entertainment Jan! Have a nice weekend
Thanks Boca! :)
When I repaired the keyboard on my Commodore PET, instead of some conductive paint I used self adhesive copper tape cut into discs using a hole punch
I would be a bit worried about the contacts on the PCB wearing down with that method but it is a nice fix, at least temporarily. :)
Un-/screwing the small keyboard screws is the best meditative part... I always enjoy that... ;)
I at least enjoy watching the sped up footage later... :D
@@JanBeta always nice with the music :)
Had the same problem on my 128DCR keyboard - the numpad "0" key in my case...
I didn't have Amiga plungers available, though. so I glued a small sliver of tinfoil on the plunger rubber itself - works without a hitch :)
I would be a bit worried about the tin foil wearing down the contacts on the PCB over time. But I imagine it is a very good fix, at least temporarily.
@@JanBeta I was too, that was the reason that I made sure it was a single layer only - that way, the plunger would keep its flexibility and the foil wouldn't scratch at the carbon.
I was more worried about the resistivity - as the tin foil is less resistive than the plunger material - basically dead short instead of a few hundred ohms.
Then again - I rarely use the numpad, so it'll be good enough for now :)
That was a nice surprise that the Amiga 500 keyboard plungers work with the C128, or at least with Mitsumi keyboard. I remember Robin at "8-bit show and tell" had a video where he had a tablet next to the C64 to display frequencies from programs in basic. Then he mentioned the 15kHz whine. I remember the sharp whine and that it gave me headaches but I have no chance of hearing it now :) Have you tried using silicone with graphite ?
Yes, quite useful that the plungers fit both keyboards. :) I think everybody loses the higher end frequencies of their hearing with age slowly. I could not hear the whine for a while. I think playing in rock bands and being an audio tech didn't help my hearing much... ;D Didn't try silicone with graphite yet. I'll have to test some different methods sometime. Lots of suggestions in the comments. :)
On my A500 I found it was the grease from the metal hoops on large keys that caused the problem. The grease liquifies, leaks inside and damages the conductive rubber. I did quite a bit of testing last year and did not find any coating that worked on the Mitsumi key conductive rubber because of the shape. Interesting that the C128 and Amiga have same contacts!
Yes, I saw your video but didn't remember... Shame on me. That may well be what happened in my case, the C128 RETURN key has one of those metal brackets, too. And I probably made it worse by wiping the contacts with IPA again.
@@JanBeta I was taught a long time ago that alcohol was bad for rubber. I learned more recently that this is only true for a few types of rubber which are commonly used for seals and gaskets. It does not hurt silicone rubber at all.
I hate chores to work on the keyboard cleaning eg all my c64'ers have done 6 or so what a job especially with my old eyes, 49 years already but is now all finished with dust cover or minimal dust cover.
Do not want to work on it for some time, some were filthy after a few years dirty and had no love.
I could have saved you the work the search for another plunger or key element, will not work with a C64, the Amigas are better suited for that, even once experienced in a gray-gray past. ;)) this is not a criticism, making old computers (or demolishing that is not so difficult) should also take a bit of searching because you have forgotten UA-cam is still a fantastic Tool.
Although it doesn't include everything, that's why I love your channel so much and do this to help each other.
I have always been a Hardware man used to pull things apart did not always end well usually :) but I learned a lot from that.
X without tongue :))
I'm constantly learning new things, I like discovering stuff myself sometimes. :)
@@JanBeta
Me To if i have the Energie...
Nice find that the plungers are identical to the Amiga Mitsumi plungers. I designed and printed a replacement plunger for an A500 (just the plastic part) using my 3D printer when I didn't have any salvaged plungers on hand. It worked quite well so it's good to know it fits the C128 as well. I put it on Thingiverse:
www.thingiverse.com/thing:3910131
Oh, nice! Thanks for sharing. :)
I'd just use a small piece of aluminium tape (used for thermal protection while using hot air) and stick it on the bottom of the plunger. It's conductive. I'm using it often lately while repairing Sega Mega Drive controllers.
As always, great video! Keep it up, Jan!
Thanks!
That's why I'm not a fan of these sort of mechanisms for a keyboard. One little slip up and you lose some keys and then you have to take the keyboard apart (insert obvious hatred of so many screws here) and then you have to get the right amount of conductive material or as you did a replacement part. That aside, at least you didn't have to do that to the entire keyboard. I've never seen it in person but is it actually possible to completely rub away the material on the plungers that easily though, I feel that as people describe it that it's as simple as alcohol rubbing can easily undo it so it's not even worth cleanin? Keep it up Jan!
Also, great hair, do what you want with it.
Yes, quite a tedious process. But at least it worked. I didn't think that it was so easy to wipe away the whole conductive layer but this fault proves me wrong I guess. Good thing I had several options to look for spare parts. :)
Ive repaired conductive rubber contacts in remote controls before by gluing a tiny piece of aluminium foil to the rubber pad(s). Its guaranteed to work. I don't have any conductive silver paint and it is expensive.
I would be a bit worried that it could damage the contacts on the PCB over time.
It makes perfect sense that the keys of the Amiga and C128 would be the same because they were ALWAYS looking to cut costs at Commodore. So using the same keyboard parts makes perfect, economic sense. You should have had a bit more faith in that :).
Haha, makes sense. To be fair to Commodore, the Amiga keyboard is a different construction apart from using the same plungers. And the same mechanism most likely was used for other Mitsumi keyboards as well. ;)
All you need to do to make C128 keyboards work again is give a light scuff on the conductive pad on the plunger, with a fine fingernail file or emery board, only *just* enough to get rid of the surface shine.
On the PCB side, scrub with a pencil eraser. You won't damage the carbon, it ain't THAT thin. 😛
The clean everything with alcohol.
Hi Jan, I wanted to ask you where I can get the power supply that appears in this video. Thank you. Nice job!
I made it myself! Video is in the C128 restoration series on my channel. :)
Always a relaxing video. Thanks. Have you tried "Bare conductive Electric Paint"
It goes on like water based paint so can be helpful for weird tracks and funny shaped pads... Yes...
Every time I see a video of you appear, I start laughing :) Not in a disrespectful way ofc.
Ha! Thanks. I guess. ;D
Great job!
Hmm...I would never think to clean the rubber pads with IPA. A common trick is to use a piece of paper and give it a slight rub. that's worked very well for me in the past.
Yes, probably a better idea. I definitely learned something. :)
Hi, love the videos and streams!
Thanks! :)
I wonder if a conductive ink pen would have worked...
They are expensive.
Yes, it would have worked. There are a number of different lacquers and paints that can be used. I didn't have any of that but the spare A500 keyboard so I figured this would be the most reasonable fix in my case. :)
Hi Jan great video on keyboard repair for the C128. I do have a question. My 128 needs the F1 & F7 plungers replaced. I have heard those use different parts than the normal keys. do you know if this is the case? or can I just use parts from an old Amiga keyboard like you did here? Thanks!
On my particular one all the plungers are the same but unfortunately there are different versions of the keyboards, some have plungers that don’t match the Amiga ones.
@@JanBeta I just want to give you an update to pass onto your viewers. I checked the top row of keys on my 128, which includes ESC, TAB, and all of the function keys, those all use different plungers than the normal keys on the lower part of the keyboard. so I would say that for letter keys & other ones on the lower keyboard, it's probably safe to use the Amiga plungers, but, for the upper keys probably not but I really can't say for sure. I may go ahead & experiment to see if Amiga plungers will do the trick. I'll check back with you then.
I can hear CRT whine even when there's no CRT around me...
I do remember going into TV shops as a kid and being hit by a giant sound from all the TVs. It wasn't very nice.
Haha, yes, I remember being a bit irritated as a kid, too. But somehow I got used to it. And as I said, I don't hear it at all anymore these days.
20:17 - Sadly, I learned this the hard way. A while ago (jeez, it was _seven_ years ago 😲), I cleaned a keyboard and scrubbed a little too hard on the end of the ribbon-cable and the conductive traces came right off. 🤦 I "recently" (almost two months ago) ordered a syringe of wire-glue from eBay and am currently waiting for it to arrive from China so that I can try to fix it. 😕
Oh, hope your plan works out. Never tried the wire glue stuff but I suppose it is going to work fine. :)
Done cleaning of lot commodore 64 or 128 keyboard cleaning, always cleaning plungers with IPA, never had issues like this. Probably plunger was already damaged.
Yes, I did it a number of times without ever having issues, too. I guess the key must have been worn down a lot previously.
BTW: You can obtain those keyboard stamps/plungers separately on eBay - without tearing an Amiga keyboard apart...
Yes, I think they were used in a number of different keyboards manufactured by Mitsumi.
@@JanBeta yes, they were used in different keyboards. I've got some of the stamps somewhere here - but can't find them at the moment...
Jan Your hair gives a Professor look. Great look! Wise!!!
Haha, thanks!
I wonder if applying a slight film of grease on the plastic clips would make then snap in and out a bit easier.
Interesting idea, it would probably work. Although ideally, you still don’t want to take apart and reassemble your hardware every other day anyway... ;)
@@JanBeta Nonsense! I've been tearing everything I own apart since about 4 years old. I don't think that will change any time soon either :-)
I did watch another youtube that did say that we should not put "heatsink" on c64/c128 chips since commodore did put thermopast on the back of the RFC sheild that works as a heatsink. So whats is your opinion on this. ?
In my experience, the metal shield often doesn't make good contact to the chips and doesn't work very well as a heatsink. I prefer to put heatsinks directly on the ICs. The RF shields are pretty useless otherwise, too, nowadays. The frequencies emitted by the old machines are not interfering with any modern electronics as far as I know.
What a strange keyboard, three of the switches are different. Could it be that a former owner already changed something?
I thought you had a frame meister or something like that. I seriously need to get a retro tink. My stupid upscaler dynamically stretches to 16:9. So playing side scrollers like sam's journey makes me a little dizzy. Static images actually look pretty good though. But yeah I'd prefer the 4:3 aspect ratio.
Oh, I have an OSSC and a RetroTink2X that I use for capturing and streaming. I only use the Flylink adapter for quick and dirty testing.
"Some young people can hear the CRT whine"
I'm glad I can be considered young. I'm one of those bloody annoying complainers..
"oi Jan! my head hurts now!"
Another fantastic Video Jan, keep it up.
You can buy graphite paint. Also useful for repairing dag on a CRT.
Yes, I definitely need some of that stuff in my arsenal. :)
Hello Jan, do you know if commodore 64 keys can be used to repair a commodore 128 broken keys?
Approximately a million" sure feels like it. just 250, 000 more than the c64
Yes!
Just trash an Amiga to save a 128 that is a 64 101% of the time.
Great job, man. 👍
If you wanna impress me, stuff an Amiga into a 128 case.
I didn’t trash any Amigas, I salvaged a plunger from a crusty, broken beyond repair A500 keyboard.
Jan Beta No offense intended mate. But can you put an Amiga into a 128 case?
I can't hear the CRT whine but somehow still identify the sound. Not if its recorded tho.
Interesting, I feel like I can still slightly hear it, too. But only very faint.
OH GOD they're like the Plus 4 keyboard :C
slt jan me when I repair old keyboard or the carbon contacts are worn by time I pass a silver-based liquid which dries after a few minutes which used to repair the defrosting of the rear windows of cars I have never found problems with this method cordially
Thanks for the tip! I am going to try some potential fixes very soon. :)
😄"don't go with, like, screwdrivers or anything like that" ... *30 seconds later*
Haha, you're right. I was using the screwdriver to reseat the metal bracket holding the key though, not to extract the keycap. ;)
wow nice good job Jan =D
Thank you. :)
I am sure you have answered this a million times but why is the manufacturer name on the lcd you use for testing your retro computers censored and why is the crt to your left displaying the same manufacturer name in the wild unhindered ?
The LIPS thing is just a joke. I like covering brand names and in this case it made a funny word. For the retro monitor, I decided to leave it as is.
Nice machine
It is!
I had the same problem and fixed it with the rubber pad from another key. Here's my video from about a month ago: ua-cam.com/video/HXpSB494Vhg/v-deo.html
Nice fix! Thanks for sharing. :)
i have two c128 keyboard and two case and a defect supply if you want it i give it to you i'm from belgium i only collect c64 and amiga stuff but not all best regard Guntattoo
Oh, appreciate the offer, but I don't really need more C128 hardware parts at the moment. Maybe somebody else needs it more?
A small droplet of glue and a smal piece of aluminium foil is all you need to fix your keys. No need for expensive paint :)
I would be worried that the contacts on the PCB get damaged with that method. But it would work for a while I guess. ;)
@@JanBeta The aluminium foil stuff you wrap food in is so soft and thin it would be worn away long before your pcb got any visible markings. It's a known way to fix old remotes...
just swap it for numeric - key......
Yes, that's another option obviously. I wanted a fully functional keyboard though.