+Larry Posted November 28, 2011 Share Posted November 28, 2011 My 1200XL keyboard was causing quite a few problems, so I decided to do the complete "1200XL Keyboard Tuneup" by Bob Woolley: http://www.retrobits.../keyboard.shtml The silicone backing still had about a half-dozen minor tears by the time I got the Mylar/silicone sheet off. Still everything went very well, and the keyboard now works perfectly! But in looking at it, I realized that I really don't understand how part of the keyboard works. Here are two picture from the "tuneup" procedure: In keyboard3 (left), we can see the remains of the original conductive tape used to complete the connections between the mylar and the keyboard PCB. Now in Keyboard4 (right), the tape residue has been cleaned off, and the silver "make-a-trace" paint has been drawn where the tape was originally. Now the part I don't understand (and hopefully someone will shed light on) -- if you look closely, it appears that the new painted traces don't really "line up" with anything. Some traces look like they would overlap two adjacent gold contacts; a couple look like they would miss any contacts. So... what is the functional relationship of these mylar contacts and the PCB? I also found a couple of things to be useful in doing this: A small square-blade "X-acto" type knife (with a light touch) was useful to me in cleaning off the tape residue from the pcb/gold contacts (not the mylar!). Next time, I think that I may make a mylar "mask" to paint the traces. Mine work fine, but they are not so neat as Bob's illustration. The silver trace material is thick, so it should not "bleed" and should be lined up better. -Larry Quote Link to comment Share on other sites More sharing options...
Gunstar Posted November 28, 2011 Share Posted November 28, 2011 I have a 1200XL keyboard I'm about to "tuneup" myself, just waiting on a new trace pen to arrive that I ordered. I didn't realize Bob had done instructions on it, I'll take a look, but I've done trace repair previously on an XE keyboard. The thing was, I have another 1200XL which has a real circuit board, and no mylar. Tuning it up was a matter of opening it up and using rubbing alcohol to clean off any grime or tarnish. It works great. I was suprised when I opened my other 1200XL with the mylar and I did manage to tear some traces when removing the mylar, as careful as I was being. I thought about ordering a new keyboard from Best E., but the keyboard is fine other than the mylar and the trace pen is cheaper. As for what you are talking about, I'll get back to you after I repair the keyboard. Quote Link to comment Share on other sites More sharing options...
unholy Posted November 28, 2011 Share Posted November 28, 2011 I think you're looking at it wrong. Or, to be more precise, in the right-hand picture, the conductive traces on the foil are not properly aligned with the PCB. They should line up with the nine central (thinner) pads on the board. Ignore the thicker ground pads on both sides and it all makes sense. Quote Link to comment Share on other sites More sharing options...
flashjazzcat Posted November 28, 2011 Share Posted November 28, 2011 Thanks for putting this up, Larry. Very timely indeed. I just had my 1200XL's keyboard apart to fix a dodgy Help key... now I'm having to do a complete service since half the other keys have stopped working. Quote Link to comment Share on other sites More sharing options...
flashjazzcat Posted November 28, 2011 Share Posted November 28, 2011 OK - fixed. The above procedure worked perfectly. Thanks Bob, and thanks Larry for posting. Quote Link to comment Share on other sites More sharing options...
Gunstar Posted November 29, 2011 Share Posted November 29, 2011 (edited) I have one question about this "tune-up"; in the instructions it talks about removing all the glue from the old tape by the edge connector, but mentions nothing about holding the mylar in place at the edge connector to make good contact when the "tune-up" is all done. That is what concerns me, so what did you do Larry or Flashjazzcat? Edited November 29, 2011 by Gunstar Quote Link to comment Share on other sites More sharing options...
+Larry Posted November 29, 2011 Author Share Posted November 29, 2011 Hi Gunstar- I did nothing. Between the thickness of the new "traces" and the clamping pressure of the (zillion) screws, it's evidently enough. I had partially done my keyboard a couple of years ago, but I bailed out when the silicone started tearing around those screws. So at that time, I just took the tape off, did a half-assed job of cleaning the residue, and painted on the new traces. Bob cautioned me to do the whole thing, but that silicone tearing scared me. I thought "well, it works fine, so leave well-enough alone." But by now, it was starting to act up again, so I got brave. After thinking about the silicone a bit, I came to the conclusion of "so what" so long as the mylar is intact. My mylar came through fine. I'm (personally) still not happy with the painted traces, but as Bob's instructions say -- "this is not easy, so don't expect perfection here." But I'm still thinking about a "better" solution for the painted fingers, and the "mask" is the best idea I've come up with thus far. Bob1200xl has had a few years to contemplate this "tuneup" (and has undoubted fixed more than a few more keyboards by now). Perhaps he might have a few new words about the fix? -Larry I have one question about this "tune-up"; in the instructions it talks about removing all the glue from the old tape by the edge connector, but mentions nothing about holding the mylar in place at the edge connector to make good contact when the "tune-up" is all done. That is what concerns me, so what did you do Larry or Flashjazzcat? Quote Link to comment Share on other sites More sharing options...
Gunstar Posted November 29, 2011 Share Posted November 29, 2011 Thanks for the reply. It looks as though I'll be waiting indefinately to do this now as I got an e-mail telling me my conductive pen is on back-order and I haven't been able to figure out how to cancel the order (the site said "in stock" else I wouldn't have ordered, obviously I'll never order from them again), so I'll have to wait I guess. Quote Link to comment Share on other sites More sharing options...
yorgle Posted November 29, 2011 Share Posted November 29, 2011 I've successfully cleaned all 7 of my 1200xl keyboards and found it easier not remove the mylar completely from the pcb. Instead, I used a paper binding clamp on the contact area, which allows you to separate the mylar far enough from the pcb to clean all the key contacts while leaving the connector contacts intact. On one keyboard where I did accidentally separate the mylar completely, I was able to get it working again without using conductive paint by sticking a bit of electrical tape above the contact area. The thickness of the tape added just enough extra clamping force to make the contact. Quote Link to comment Share on other sites More sharing options...
+bob1200xl Posted November 29, 2011 Share Posted November 29, 2011 You know, I tried electrical tape, way back when. It seems reasonable, but there is more to it than that. (pressure) The k/b seems to be assembled OK, but the connection from the mylar to the PCB goes 'bad'. One way you can improve this is to shift the position of the mylar relative to the PCB. By drilling out the locating pin holes just a little bit, you can re-assemble the k/b with just a minimal offset from when it was built. This seems to work pretty well on most k/b. Some well used k/b cannot be brought up without cleaning the gold contacts on the PCB. Some require silver paint, some do not. Larry mentioned a mylar mask to make it easier to apply the paint - I vote for that! As far as the rubber/silicone sheet, don't even think that warming it up will help it separate from the PCB. It melts at 98.7F. Go slow... Bob I've successfully cleaned all 7 of my 1200xl keyboards and found it easier not remove the mylar completely from the pcb. Instead, I used a paper binding clamp on the contact area, which allows you to separate the mylar far enough from the pcb to clean all the key contacts while leaving the connector contacts intact. On one keyboard where I did accidentally separate the mylar completely, I was able to get it working again without using conductive paint by sticking a bit of electrical tape above the contact area. The thickness of the tape added just enough extra clamping force to make the contact. Quote Link to comment Share on other sites More sharing options...
KLund1 Posted November 29, 2011 Share Posted November 29, 2011 One way you can improve this is to shift the position of the mylar relative to the PCB. By drilling out the locating pin holes just a little bit, you can re-assemble the k/b with just a minimal offset from when it was built. I 2nd this. Works every time I had the similar problem with 1200's. (even a few 800xl's, and some ST's) This has been documented elsewhere in this forum a few years ago. (bob1200xl the is the goto guy for any 1200xl questions, or A-8-bit for that mater!!!) Quote Link to comment Share on other sites More sharing options...
Roydea6 Posted November 30, 2011 Share Posted November 30, 2011 http://www.atariage.com/forums/topic/104583-tipstricksproducts-used-in-restoration/page__view__findpost__p__1268741 Closer view of this fix is here at Atatiage in the tips and tricks STICKY. Quote Link to comment Share on other sites More sharing options...
flashjazzcat Posted November 30, 2011 Share Posted November 30, 2011 Mine was OK for a couple of days after I repainted the traces, but it started acting up again tonight. TWO layers of insulation tape over the contact area appear to have solved the problem... I hope. This keyboard's been apart more times than Paris Hilton's knees. 2 Quote Link to comment Share on other sites More sharing options...
+Stephen Posted November 30, 2011 Share Posted November 30, 2011 Mine was OK for a couple of days after I repainted the traces, but it started acting up again tonight. TWO layers of insulation tape over the contact area appear to have solved the problem... I hope. This keyboard's been apart more times than Paris Hilton's knees. Well, unlike Paris, I guess fingering that keyboard won't give you a disease Quote Link to comment Share on other sites More sharing options...
Gunstar Posted December 2, 2011 Share Posted December 2, 2011 Well, I got my conductive pen today, ordered on Saturday, so less than a week even though my order still says "back ordered" on the website. Anyway, I got it from Grainger online, supposedly on clearance with limited supply. The pen was only $6 compared to others selling for $15-25. Of course S&H was $9 plus tax, so I ended up paying about $17. But still a good deal if you add in S&H on the $15-25 pens. I have a pic below, it's a fine tip on it and you can see some test traces I made on the package, pretty clean and not too much mess, even after going back and forth several times with the pen. I think this one will work great for my 1200XL mylar. 1 Quote Link to comment Share on other sites More sharing options...
Roydea6 Posted December 2, 2011 Share Posted December 2, 2011 Well, I got my conductive pen today, ordered on Saturday, so less than a week even though my order still says "back ordered" on the website. Anyway, I got it from Grainger online, supposedly on clearance with limited supply. The pen was only $6 compared to others selling for $15-25. Of course S&H was $9 plus tax, so I ended up paying about $17. But still a good deal if you add in S&H on the $15-25 pens. I have a pic below, it's a fine tip on it and you can see some test traces I made on the package, pretty clean and not too much mess, even after going back and forth several times with the pen. I think this one will work great for my 1200XL mylar. I wonder if this stuff would work to repair the 130xe connections MyLar to Motherboard connector. TIA Quote Link to comment Share on other sites More sharing options...
Gunstar Posted December 2, 2011 Share Posted December 2, 2011 (edited) I'd say it probably would, if you can keep from rubbing it off when inserting it in the mobo connector. I have repaired an XE mylar before using a similiar product (circuit writer), but it was on a trace that would not be touched by anything. I can't say how durable this conductive paint would be when being inserted into the connector which naturally holds the mylar tight. Edited December 2, 2011 by Gunstar Quote Link to comment Share on other sites More sharing options...
+Larry Posted December 2, 2011 Author Share Posted December 2, 2011 Are you referring to the end of the mylar (that goes into the mobo connector) or just repairing the traces further back? If it's the part that goes inside, I'd be concerned about the stuff flaking off inside the mobo connector. FWIW -- if you have a problem at the end of the mylar, did you consider just trimming off about 1/4" or so of the mylar? I did that on a 130XE, and it worked out great. -Larry I wonder if this stuff would work to repair the 130xe connections MyLar to Motherboard connector. TIA Quote Link to comment Share on other sites More sharing options...
Gunstar Posted December 3, 2011 Share Posted December 3, 2011 (edited) I was just coming here to suggest the same thing. I cut off a bit of the end of a 130XE mylar connector years ago, it was the same I already refered too above fixing a trace, I'd just forgotten that I also trimmed a connector that I damaged from to many removals and re-insertions while doing multiple upgrades to the 130XE at different times. Edited December 3, 2011 by Gunstar Quote Link to comment Share on other sites More sharing options...
Roydea6 Posted December 5, 2011 Share Posted December 5, 2011 Well, I got my conductive pen today, ordered on Saturday, so less than a week even though my order still says "back ordered" on the website. Anyway, I got it from Grainger online, supposedly on clearance with limited supply. The pen was only $6 compared to others selling for $15-25. Of course S&H was $9 plus tax, so I ended up paying about $17. But still a good deal if you add in S&H on the $15-25 pens. I have a pic below, it's a fine tip on it and you can see some test traces I made on the package, pretty clean and not too much mess, even after going back and forth several times with the pen. I think this one will work great for my 1200XL mylar. Ten minutes of calling and ten miles of driving I was able to get a conductive pen, and now my XE's are back up and running. Only on one(1) of the XE's did I need to trim the mylar about 1/8 inch to get it working. Most of the problem was with the mylar connector having broken traces form incerting into motherboard connector. The paint did not scrub off during the first and second incersions, I heat lamp the paint overnight. Quote Link to comment Share on other sites More sharing options...
Gunstar Posted December 5, 2011 Share Posted December 5, 2011 (edited) Glad it worked for you. I haven't fixed mine yet, but while I will file your heat lamp tip away for future use, my repairs won't need it as they are traces that won't ever be disturbed once it's all back together. What did you pay for your pen? What brand? Edited December 5, 2011 by Gunstar Quote Link to comment Share on other sites More sharing options...
Roydea6 Posted December 5, 2011 Share Posted December 5, 2011 It was Radio Shack: 19.99. http://www.radioshack.com/product/index.jsp?productId=3964901# Quote Link to comment Share on other sites More sharing options...
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