AEKII Bad Key on Keyboard

Discussion in 'Apple Collectors' started by bunnspecial, Feb 27, 2015.

  1. bunnspecial, Feb 27, 2015
    Last edited: Feb 28, 2015

    bunnspecial macrumors 603

    bunnspecial

    Joined:
    May 3, 2014
    Location:
    Kentucky
    #1
    I'm typing this post from an AEKII that I've recently pressed into service with my Quicksilver via a Griffin iMate. I've had this keyboard for a while-although admittedly not used it extensively and not for the sort of typing I've been doing recently. All of my past use with this particular keyboard has been on ADB equipped Macs, although as I said I've not done a huge amount of typing on it.

    To make a long story short, I decided to press this keyboard into service for dissertation writing duties, and in a day or so of using it I've noticed a very annoying problem.

    Specifically, the "P" key is very difficult to actuate. There's no discernible difference in pressure or feel on the key, but it only seems to work on one out of every 10 or so presses(if that often). Sometimes, it works with no discernible problem and with no additional pressure(I haven't measured recently, but would guess that I type at 40-50 WPM with a normally functioning keyboard, and could probably type faster with this one if it worked normally). At other times, I have to really bang on the key to get it to register.

    I've pulled the cap and given the switch a good shot with compressed air. Is there anything else I can do to potentially fix the problem? If I could find a replacement switch, it would be great. I'd also be open to swapping it out for a less-used switch like one of the F keys where I really wouldn't miss it.

    If it's of any relevance, this is a model M3501, serial number AP0340RJ%M0312. It has the "clicky" Alps switches and not the cushioned ones of some of the AEKIIs, and the height adjustment slider is white.

    I've used the iMate before with my other AEKII(which has the cushioned switches) but would really like to get it working at 100% since I prefer "clicky" switches for serious tying work.

    Any thoughts on any of this?

    (or should I just drive to Lexington tomorrow and buy a USB Unicomp Spacesaver M at the factory to get my clicky key fix)

    ----------

    EDIT:

    Apparently I have the "damped" Alps switches as per this reference

    http://deskthority.net/wiki/Apple_Extended_Keyboard_II


    Mine was Made in the US, and has the "s" in a square on the label. I'm not sure this makes any difference for repair purposes, and I guess also I'd forgotten how loud a model M is.
     
  2. bunnspecial thread starter macrumors 603

    bunnspecial

    Joined:
    May 3, 2014
    Location:
    Kentucky
    #2
    Okay, I think that it might be fixed at least somewhat. I took it apart, and also removed the caps both from the "P" key and every other key surrounding it.

    I cleaned the area around the removed keycaps with alcohol, as well as blew a lot of compressed air(or more properly canned air) between the circuit board and the metal plate that the keys press up against pretty thoroughly. All I have at home is canned air-I might take it into work on Monday and used compressed air rather than canned air to really get it cleaned, since what I did improved it a lot but didn't fix it completely. I'm now getting about 1 out of 5 Ps missed, although occasionally it throws out a long stream of them when I press the key with what I'd consider a "normal" press. Typing this post wasn't anywhere near as frustrating as typing my last one.

    I also checked the circuit board pretty thoroughly in the area around the P key for a possible fractured or cold solder joint. It was hard to line things up exactly, but I at least didn't see anything suspicious(although I'm also not entirely sure if the Alps switches are mounted directly on the PCB which I could access).

    I still might drop by Unicomp tomorrow and pick up a buckling spring keyboard, though :) . I've been meaning to get one for a while, and I like supporting a local company especially now that they make something with Mac keycaps and Mac-specific keys.
     
  3. MacTech68 macrumors 68000

    MacTech68

    Joined:
    Mar 16, 2008
    Location:
    Australia, Perth
    #3
    You could try spraying a mild contact cleaner into the switch and then working it a few 10's of times. I've even flooded the switch with contact cleaner whilst the switch is upside-down, in the hopes of 'flushing' the housing, with limited success.

    Ultimately, swapping the switch is the better option and I've actually done what you suggest before, swapping a rarely used switch for the faulty one.

    I've even pulled the switches apart and refurbished them, though that requires much care no to break clips or bend the contacts inside.

    The only real issues are, getting the switch out (defeating the clips can feel frustrating the first time you do it), and switches with worn shafts or shaft apertures that tend to grab when hit at an angle, though this one doesn't sound like it's worn.

    If you're using compressed air, make sure it has a dehumidifier and try not to blow the air into the switches, rather use a direction perpendicular to the switch shaft. After you've removed the bulk of dust, hair and 'whatnot', you can use a soft brush for extra 'budge' - make sure your brush isn't dropping hairs.

    I guess the object is to remove dust whilst trying to not force any into the switches or switch shaft. Not particularly easy, but if it's very dusty, the likelihood of dust getting into the switches as you move the keyboard means removing it is probably worth the risk.
     
  4. bunnspecial thread starter macrumors 603

    bunnspecial

    Joined:
    May 3, 2014
    Location:
    Kentucky
    #4
    Thanks for the detailed explanation.

    I tried to remove the "bad" switch last night, but couldn't really get it to go anywhere. Are there any particular tricks to getting the switches out-especially without messing something up? I have bad visions of sending springs flying when pulling a switch.

    If it's easy to do, I'll just pull out the F3 switch(or one of the other F keys that I never use) and switch them out.
     
  5. MacTech68 macrumors 68000

    MacTech68

    Joined:
    Mar 16, 2008
    Location:
    Australia, Perth
    #5
    Some suggest not removing the whole switch but rather disassembling the switch 'in situ'. I don't prefer that method, unless you want to refurbish the switch.

    The way to remove them (after desoldering the two pins on the solder side such that they freely move in the holes), is to defeat the four wings that prevent the switch body from being removed. You also need to defeat the two tabs that latch the switch to the frame.

    So, there are four small wings (one in each corner) that spring outward, and there are two large tabs (one on each opposite side) that need to be released. I find that releasing one side at a time works best. It's tedious, and you can release one side, only to have it snap back when trying to release the other side.

    This drawing of a third party replacement shows a top and bottom view where you can see the 'wings' in the four corners.

    http://matias.ca/switches/click/blueprints/?p=4
     
  6. bunnspecial thread starter macrumors 603

    bunnspecial

    Joined:
    May 3, 2014
    Location:
    Kentucky
    #6
    Thanks for the added info.

    I'd intended to tackle this after the University of Kentucky basketball game this evening :) , but got sidetracked with lapping the heatsink on my Quicksilver processor upgrade-as well as the surprisingly maddening task of trying to move all the data and settings over from my old iPhone 4s to my new iPhone 6.(Kentucky is now 29-0 on the season, my Quicksilver is now faster than the fastest factory G4, and my iPhone still isn't set up right :) ).

    From the reading I've done, both at your link and elsewhere, it looks like I just need to spend a few minutes with the soldering iron getting the old switch loose and then either take it apart and tinker with it or borrow one from somewhere else on the keyboard.

    The only potentially diffcult part looks to be figuring which solder points exactly go with the key that's giving me issues.
     
  7. bunnspecial thread starter macrumors 603

    bunnspecial

    Joined:
    May 3, 2014
    Location:
    Kentucky
    #7
    Okay, I just finished doing a teardown and rebuilt of the switch in question.

    Fortunately, I was able to get it to work well enough that I could hold pressure on the key and then use my VOM to check the circuit board for the correct solder point.

    Once that was done, I unsoldered the bad key switch and disassembled it as per a guide I found online for Alps switches. Basically, the guide suggested bending the contact "fingers" in closer to each other(with the switch apart). While it was apart, I also took the chance to do some(careful) cleanup on the contacts. I checked the reassembled switch for continuity when pressed and it worked. I then soldered it back into place.

    I'm typing this message from the keyboard, and have not had a single "dropped" P in the course of typing this. I also haven't had any "out of control" Ps as happened occasionally after my first repair that I wrote about earlier.

    The guide I was following mentioned that the repair could result in a slight increase in key pressure, but I honestly don't notice it.

    I need to sit down and write a rec letter this afternoon, so that will be its real test. For the time being, though, I'm calling it fixed.

    I also got my new iPhone synced, and my Quicksilver passed an 8 hour stress test at 1.6ghz. Now I just need to see if I can push it to 1.8ghz :) .
     
  8. MacTech68 macrumors 68000

    MacTech68

    Joined:
    Mar 16, 2008
    Location:
    Australia, Perth
    #8
    Nicely done. Hopefully it's a lasting repair, and you won't be P-ing all over the place anymore. ;)
     
  9. bunnspecial thread starter macrumors 603

    bunnspecial

    Joined:
    May 3, 2014
    Location:
    Kentucky
    #9
    Thanks!

    P seems fine, but unfortunately O seems to be getting a bit "touchy" now. I'll probably save that for next weekend, but now that one is behind me the rest don't seem so daunting.

    I guess that one must really like a keyboard to put this much effort into fixing it :)

    And I'm still going to try and make it to Lexington one day this week to pick up a Unicomp...
     
  10. MacTech68 macrumors 68000

    MacTech68

    Joined:
    Mar 16, 2008
    Location:
    Australia, Perth
    #10
    When original Apple ADB keyboards were worth over $100, a bad key was well worth it. These days, yes, if you like the feel and layout, it's STILL worth it.

    Reminds me of repairing HP DeskWriters when they were worth several 1000 dollars!! :eek: These days, not so much. ;)
     
  11. bunnspecial thread starter macrumors 603

    bunnspecial

    Joined:
    May 3, 2014
    Location:
    Kentucky
    #11
    Yes indeed-plus, now that I have one behind me, I feel pretty confident about tackling others if and when they come up.
     
  12. bunnspecial thread starter macrumors 603

    bunnspecial

    Joined:
    May 3, 2014
    Location:
    Kentucky
    #12
    Looks like "8" is giving out on me also.

    It looks like I'm going to be playing "whack a mole" on this keyboard...maybe once I get my dissertation finished I'll rebuild the whole thing. Now that I've tackled one, at least I know it can be done...it's just a big job to unsolder, disassemble, clean, reassemble, and resolder all 100+ key switches.
     
  13. bunnspecial thread starter macrumors 603

    bunnspecial

    Joined:
    May 3, 2014
    Location:
    Kentucky
    #13
    I just finished rebuilding "O" and "8", and both are now working perfectly. I had the foresight to take pictures of my most recent venture into the keyboard, so am going to try and write the keyswitch rebuild up as a guide. I know it's probably old news to many of you here, but I figure it won't hurt to detail what I learned about what to do, what not to do, and give pictures of exactly what I did since so far everything seems to work great.
     

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