Thanks for the added detail. I haven't yet opened up my trusty old Atari 800 that I finally got back from my sister's basement after thirty years, but its keyboard doesn't work at all. I'm not even sure I have a mylar membrane keyboard. I just know my keyboard felt much better than on the early models that I used at the library, comparable to the keyboard on the used 1200XL I got back then just to see what the differences were. I have an extra 1200XL keyboard if I need it, but that's not the problem I'm having with that one. Your explanations have helped a lot, but I'm going to look for more videos of people actually mending a mylar membrane keyboard, but of course first I have to determine that I have one.
Since no one has made 800 mylar replacements yet, and the hairdryer method poses some possible danger, might I suggest an alternative method first developed long ago by Bob1200XL on AA for 1200XL keyboards before mylar replacement were available. Drill out the screw and guide holes to the next bigger drill bit size in the keyboard PCB. There is no danger to traces doing this. About 1mm larger, but no more, or you loose the traces' contact points on the PCB edge. Then rebuild the KB with a few screws in the corners and middle but leave them slightly loose. Next, push the PCB to the left against the screws and then tighten, and test. This puts the mylar contact in slightly different place on the PCB. This plus a light ISO q-tip clean on the PCB contacts (not the mylar!!) and this usually fixes the issue 97% of the time. If some keys still not working, loosen the screws and shift the PCB right, up, down, or diagonal, and re-test. When working be sure to replaces the rest of the screws. This method leaves this fix available in the future if needed (use a different direction). Also putting a post-it under the KB describing what as done and what direction used will help in the future as well. fyi
@@powerofvintage9442 I use cream. but the process is much, much different. This works great on all vintage plastics. First you need warm sunny day, a flat concrete area in that sun, a garden hose, a 5" cheap plastic low nap paint roller, and a large clear/semi-clear plastic storage box, big enough to cover whatever you are briting. I use developer 30. Use gloves! Use a paint brush to apply cream to the unit. Use the bristles to get the cream in the the crevices. Try and smooth out the cream in the crevices. Then paint the rest of the unit, not too thick. Next use the roller to even out the cream. You will probably need to squeeze out the roller a couple times. You really want an even coat. It is ok if you cant see the cream. You just want it to look wet. Now the fun. Use the garden hose to thoroughly wet an area on the pavement a little bigger then the plastic container. Place the just cream painted item with the worst yellowing facing the sun. Put the plastic box over the item. Wait... 80' day, 30 developer, 1 hour. 90' day, 30 developer, 30 minutes. Divide by 2 for 40 developer. Multiply by 2 for 20 developer. Check progress, lift box so that condensation dose not fall on item. Repeat until color is back to where you want it. Add water to the pavement each time. but do not spray water on the unit. I use a small bucket. The 800 in this video , I think would take about 2+ hours and it will look new again. The trick here is the even spreading of the cream, and keeping it in a moist environment. That stupid way of using cling wrap tries to keep it moist, but the clumpiness invites that 'blooming" effect. This dose not happen with my method, if you are a good painter and roller person. Oh, I forgot preparation. Wash the unit to get all the dirt and grim off. Then give it a once over with a wet Magic Eraser. Not too hard, but you will see how much more dirt comes off. Also it is a very fine sandpaper. It removes a few molecules layers of plastic off the surface. This seems to help the developer 'get into' the plastic and gives a quicker and deeper restoration. Once the item is to the color you like, give it a good washing. Use a brush to get into the crevices, and also clean the inside. The cream always works its way inside the case. Wipe it down with a towel and put it back in the sun to fully dry. Then wipe it down with some 303 protection spay while warm. I've done this with units 10-12 years ago and they still look new, They have not started to yellow again. I really should make a video about this. This process is simple, cheap, easy to do. Those funny boxes with foil and blue lights and fans take days and is expensive for the lights. My process takes a couple hours. The only variable is a warm sunny day is needed. Good Luck !!
I'm happy my 800 has a mechanical keyboard. I've had to deal with enough mylar on my 600xl.
Thanks for the added detail.
I haven't yet opened up my trusty old Atari 800 that I finally got back from my sister's basement after thirty years, but its keyboard doesn't work at all.
I'm not even sure I have a mylar membrane keyboard.
I just know my keyboard felt much better than on the early models that I used at the library, comparable to the keyboard on the used 1200XL I got back then just to see what the differences were. I have an extra 1200XL keyboard if I need it, but that's not the problem I'm having with that one.
Your explanations have helped a lot, but I'm going to look for more videos of people actually mending a mylar membrane keyboard, but of course first I have to determine that I have one.
Since no one has made 800 mylar replacements yet, and the hairdryer method poses some possible danger, might I suggest an alternative method first developed long ago by Bob1200XL on AA for 1200XL keyboards before mylar replacement were available. Drill out the screw and guide holes to the next bigger drill bit size in the keyboard PCB. There is no danger to traces doing this. About 1mm larger, but no more, or you loose the traces' contact points on the PCB edge. Then rebuild the KB with a few screws in the corners and middle but leave them slightly loose. Next, push the PCB to the left against the screws and then tighten, and test. This puts the mylar contact in slightly different place on the PCB. This plus a light ISO q-tip clean on the PCB contacts (not the mylar!!) and this usually fixes the issue 97% of the time. If some keys still not working, loosen the screws and shift the PCB right, up, down, or diagonal, and re-test. When working be sure to replaces the rest of the screws. This method leaves this fix available in the future if needed (use a different direction). Also putting a post-it under the KB describing what as done and what direction used will help in the future as well. fyi
That computer is so ugly that it should be burned not fixed.
A good Retro-Brite and it will look as good as new ! I have a great method for doing this for 800's
@@KLund1100 awesome! what path do you use, vapor, immersion? I will not use the cream method (had a bad experience previously on a Mac)
@@powerofvintage9442 I use cream. but the process is much, much different. This works great on all vintage plastics. First you need warm sunny day, a flat concrete area in that sun, a garden hose, a 5" cheap plastic low nap paint roller, and a large clear/semi-clear plastic storage box, big enough to cover whatever you are briting. I use developer 30. Use gloves! Use a paint brush to apply cream to the unit. Use the bristles to get the cream in the the crevices. Try and smooth out the cream in the crevices. Then paint the rest of the unit, not too thick. Next use the roller to even out the cream. You will probably need to squeeze out the roller a couple times. You really want an even coat. It is ok if you cant see the cream. You just want it to look wet. Now the fun. Use the garden hose to thoroughly wet an area on the pavement a little bigger then the plastic container. Place the just cream painted item with the worst yellowing facing the sun. Put the plastic box over the item. Wait... 80' day, 30 developer, 1 hour. 90' day, 30 developer, 30 minutes. Divide by 2 for 40 developer. Multiply by 2 for 20 developer. Check progress, lift box so that condensation dose not fall on item. Repeat until color is back to where you want it. Add water to the pavement each time. but do not spray water on the unit. I use a small bucket. The 800 in this video , I think would take about 2+ hours and it will look new again.
The trick here is the even spreading of the cream, and keeping it in a moist environment. That stupid way of using cling wrap tries to keep it moist, but the clumpiness invites that 'blooming" effect. This dose not happen with my method, if you are a good painter and roller person.
Oh, I forgot preparation. Wash the unit to get all the dirt and grim off. Then give it a once over with a wet Magic Eraser. Not too hard, but you will see how much more dirt comes off. Also it is a very fine sandpaper. It removes a few molecules layers of plastic off the surface. This seems to help the developer 'get into' the plastic and gives a quicker and deeper restoration. Once the item is to the color you like, give it a good washing. Use a brush to get into the crevices, and also clean the inside. The cream always works its way inside the case. Wipe it down with a towel and put it back in the sun to fully dry. Then wipe it down with some 303 protection spay while warm. I've done this with units 10-12 years ago and they still look new, They have not started to yellow again.
I really should make a video about this. This process is simple, cheap, easy to do. Those funny boxes with foil and blue lights and fans take days and is expensive for the lights. My process takes a couple hours. The only variable is a warm sunny day is needed. Good Luck !!