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View Full Version : Compaq Portable Keyboard repair ideas and an offer



bettablue
October 28th, 2012, 03:00 AM
I know I already have a thread under PCs and Clones regarding the Compaq Portable keyboard, but because of the design of this keyboard and its similarity to several other computer manufacturers keyboards, I thought I would start a new thread here asking for help.

As of right now, I am at a complete loss as to what to do next. Personally, this keyboards design has a lot to be desired, so I was thinking of several mods that may, or may not be feasible. The first one it to remove all of those padded metallic disks, and replace them with a rubber membrane from a dome type keyboard. Of course, since the Compaq keyboard is operated by changes in capacitance, I would still want to cover the metallic dot in the center of the dome with some very thin material, or even lay a very thin sheet of clear packing tape over the circuit board to keep the pieces from making direct contact. What I like about this mod is the fact that it will not change the way the keyboard registers key strokes. But there are some drawbacks to this too. The first of which would be how to activate the key switch. I suppose it would be simple enough to make a small actuator that would press down onto the rubber dome causing it to collapse and register the key stroke.

Another method I was thinking about would definitely be a drastic measure, but it could be done. This time I'm talking about building a completely new keyboard face and fill it with Cherry Blacks, or Browns. These mechanical key switches would virtually never wear out, certainly not in the lifetime of the Compaq Portable. The drawbacks on this solution are numerous. Like, for instance, the keyboard would need an entirely new internal controller chip to convert the signals to something the computer would recognize.

Lastly, one more solution would be to somehow retrofit an IBM AT style of key switch. The keyboard would not require an engineering degree in order to perform this rebuild, but the parts required would mean the destruction of at least one, possibly two keyboards in order to rebuild the actuator assembly in the Compaq's Keyboard case.

The main issue I have with all three options here, is that I don't have the equipment to perform work even close to the caliber of that required to do the rebuilds.

Now, since my Compaq Portable keyboard is still dead, well, not completely. I do get some keys that will register properly, but there are just way too many that when the key is pressed, it will cause the computer to display a weird string of characters. I'll actually get about 10 to 12 alphanumeric characters on the screen. So that leads me to believe that my keyboard is at least salvageable. So, here is what I propose. I don't have a lot of money, and because I am on disability, I won't be getting much of an allowance from my wife after the bills are paid. Yet, that will still give me roughly $50.00 to spend, not including shipping. So if someone can perform a proper refurb on my Compaq Portable for the money, I will be ecstatic!

Please PM me and let me know first off, where you live; so I can figure round trip postage. Then, when you want the keyboard sent to you. Finally, I would like to know how you plan to resolve my keyboard's issues and roughly how long to expect the keyboard to be out. (Not that it really makes that much of a difference, mind you, but I am still curious)

Thanks everyone for reading.

I'll await your responses.

arrow_runner
March 16th, 2013, 06:04 PM
I'm in the beginning stages of refurbishing my Portable I keyboard right now. I'm just curious as to what you ended up doing with yours? I also thought about using the rubber caps, but I could not get anything to adhere to them and gave up after trying a lot of different things. Right now I'm about to look for some foam and just make it like it was from factory.

I do have another question though. You said that this keyboard worked by a change in capacitance. I'm not exactly sure how that works here. Does that mean I can't use a piece of aluminum foil if I lost one of the metallic disks?

Edit: Nevermind on the second question. Guess I'm going to have to look harder for the disks that I dropped...

bettablue
March 17th, 2013, 09:32 AM
I'm in the beginning stages of refurbishing my Portable I keyboard right now. I'm just curious as to what you ended up doing with yours? I also thought about using the rubber caps, but I could not get anything to adhere to them and gave up after trying a lot of different things. Right now I'm about to look for some foam and just make it like it was from factory.

I do have another question though. You said that this keyboard worked by a change in capacitance. I'm not exactly sure how that works here. Does that mean I can't use a piece of aluminum foil if I lost one of the metallic disks?

Edit: Nevermind on the second question. Guess I'm going to have to look harder for the disks that I dropped...


Almost all of the foam padded disks were completely destroyed. The foam was disintegrated to the point that just opening the keyboard would cause some to fall off. I have a contact I found on the web who will make a full set of those disks for about $39.95 plus shipping. Because of the nature of the materials used in the construction of this board, he has to wait for about mid Spring for the weather to get warm enough for him to work in his garage.

I'm waiting patiently for the day when I am notified that he's operating again. I'll post something here as soon as he's operating again.

And just to back up your thoughts regarding the aluminum; don't. The board doesn't use a diret contact like most. In fact, if you were to use any kind of conductor as a contact key switch, you could and probably will damage the keyboard's controller sooner, or later...

Hope this helps.

arrow_runner
March 17th, 2013, 11:02 AM
Yeah the foam on mine is disintegrated just like yours. The backspace and enter key were the first to go. Luckily I could use the ALT+Keypad for the ascii codes of what I wanted to do before I shut it down last.

I thought it was really weird when I checked for resistance across those metallic disks and got nothing. It's a good thing I stopped where I was.

Does this person have a website? I'll probably take another look at it this week but I'd probably be willing to wait and pay that if it's a good solution.

bettablue
March 17th, 2013, 11:28 AM
Yeah the foam on mine is disintegrated just like yours. The backspace and enter key were the first to go. Luckily I could use the ALT+Keypad for the ascii codes of what I wanted to do before I shut it down last.

I thought it was really weird when I checked for resistance across those metallic disks and got nothing. It's a good thing I stopped where I was.

Does this person have a website? I'll probably take another look at it this week but I'd probably be willing to wait and pay that if it's a good solution.

Send me a PM with your Email address and I'll forward you his address. The guy is pretty picky, so don't try to contact him at least till 4/15/2013. He does great work in recreating what appear to be original foam pads, complete with Mylar for capacitance registration and keystrokes.

Chromedome45
March 17th, 2013, 01:01 PM
Hi BB, I have heard that the ESD foil which boards or RAM come in works pretty well in place of foil.