jjh76 Posted January 5, 2018 Share Posted January 5, 2018 I just bought an aluminum TI off ebay and was a bit surprised at the size - the one my family had when I was a child is so much bigger in my memory. It wasn't mentioned in the listing and I didn't pay enough attention to the pictures so didn't realize it had no power cord, so I don't even know if it works. Found a listing for a pair of "tested" original cords, but we'll see... In the meantime, I pulled it apart to clean it up and check the pcb and didn't see any red flags like corrosion or leaky caps. The keyboard however was a mess. I managed to get the keys off without breaking anything and after a soak in soapy water they cleaned up nicely. The metal bracket that holds the switches is speckled with small spots of rust. Is there an easy way pull those plastic clips off the tops of the switches so I can sand and re-paint the metal? Also - is it safe to spray the switches with WD-40 or some other lubricant or would that wreck the plastic parts? Quote Link to comment Share on other sites More sharing options...
jjh76 Posted January 7, 2018 Author Share Posted January 7, 2018 Ok, the power cord I ordered arrived today. Decided not to mess with the keyboard after cleaning it and just put everything back together as-is. The computer boots up fine, no problem reading carts and the speech synthesizer works as it should with Parsec. Keyboard is not good. These keys don't work at all: 9 U I S F G H J C V N . enter and these keys occasionally work: = O B Quote Link to comment Share on other sites More sharing options...
spacecadet Posted January 7, 2018 Share Posted January 7, 2018 I would spray the switches with Deoxit rather than WD-40... but honestly, it sounds like this thing is pretty far gone, and these things are *super* cheap to get in basically mint condition. I'd probably just chalk it up as a learning experience and get another one, keeping the first one around for whatever spare parts you can salvage. If you do want to try to fix it just for fun, try Deoxit first; I'll bet that at least fixes the keys that occasionally work, if not all of them. I think wrecking the plastic is probably not worth worrying about at this point. But my experience is that Deoxit does not affect plastic if you wipe it off reasonably quickly. Quote Link to comment Share on other sites More sharing options...
jjh76 Posted January 7, 2018 Author Share Posted January 7, 2018 Meh, it's not the keys it's the connector wires. Time to get out the soldering iron Quote Link to comment Share on other sites More sharing options...
+mizapf Posted January 7, 2018 Share Posted January 7, 2018 Take care - the connector wires become so brittle that every little bending will break them. If you fetch your soldering iron, consider replacing the whole flat cable. 1 Quote Link to comment Share on other sites More sharing options...
+Ksarul Posted January 7, 2018 Share Posted January 7, 2018 Definitely replace the flat cable, or your problem will return relatively quickly. . . Quote Link to comment Share on other sites More sharing options...
jjh76 Posted January 16, 2018 Author Share Posted January 16, 2018 Not really a cable on this one, just a lot of individual wires with a strip of clear tape across one side. Spliced in some new wires, when plugged in my multimeter shows continuity from the keyboard solder points to the connector solder points on the main board but some keys still not working. Don't have deoxit at any of the stores around here, but have some stuff called QD contact cleaner which works pretty good cleaning cartridges. Sprayed it into the switches and some of the keys that weren't working work now, but some of the ones that did work now don't. Gave up (for now) and bought another TI off ebay. This one actually had the box with the clamshell styrofoam insert and some of the original documents. Turned on when I plugged it in, but the screen is orange and the text is all scrambled. The keyboard works though and the case looks nicer so I swapped the main board with the other one. So now I have one nice looking good TI, and one slightly less nice (but still not too bad looking) TI with an orange screen and a bad keyboard. Quote Link to comment Share on other sites More sharing options...
Opry99er Posted January 16, 2018 Share Posted January 16, 2018 Sucks, man... sorry to hear of your troubles. I have 4 consoles, 3 of which freeze at start up. Quote Link to comment Share on other sites More sharing options...
+mizapf Posted January 16, 2018 Share Posted January 16, 2018 Have you checked https://www.ninerpedia.org/wiki/Troubleshootingconcerning the video issues? Quote Link to comment Share on other sites More sharing options...
jjh76 Posted January 16, 2018 Author Share Posted January 16, 2018 Thanks, what I'm getting is the same as the image for 11111110. If I understand it correctly, then that means the left most chip labeled 7 is the bad one? Quote Link to comment Share on other sites More sharing options...
jjh76 Posted January 31, 2018 Author Share Posted January 31, 2018 Meh, I don't like the keyboard I pulled out of the bad one. Instead of the single switch like on the Alps, the spacebar on this one has three switches and they keep binding on me, requiring more force to push it down. And instead of the nice steel bracket on the Alps it only has the circuit board to hold it in place. So, after picking up a solder sucker and a new soldering iron at the local Micro Center (one of the cheaper ones but still better than the one I had) I went and completely disassembled the Alps board. (I mean, it's already bad so why not?) After some very careful poking about with a micro flathead screwdriver and a few pieces of wire I was able to get one of the switches apart without breaking the plastic. After seeing how it works I took the little piece of metal that pushes against the contacts and bent it a little to make better contact with the plunger. Put it back together and used my mutlimeter to check continuity and the dead switch is now working. One down, forty-seven to go...... was originally just gonna try to fix only the dead ones but then said to myself ,"what the hell, just do em all" 4 Quote Link to comment Share on other sites More sharing options...
Machead Posted February 23, 2018 Share Posted February 23, 2018 (edited) After some very careful poking about with a micro flathead screwdriver and a few pieces of wire I was able to get one of the switches apart without breaking the plastic. I've been watching this thread with interest, as I also really like the alps-style boards; my very first 99/4a (also my first computer, period) was an early beige model that came with a beige keyboard with yellow alps-style switches. I still have this computer and it's still my primary 99/4a, but at some point the yellow stem on the left Shift key snapped off. I blame my brother. In any case, my question for jjh76 is whether you could post pictures, a short video, or even some descriptive text about how you took these switches apart. I do have a spare beige alps keyboard that is in about the shape yours started in (a dozen or so keys don't work) that I'm very willing to cannibalize for switch parts to repair my sentimental favorite, which is working fine except for the one broken stem. However, since ol' faithful is working so well, I'd rather not desolder and pull it all to pieces if I don't have to. Is it possible to disassemble these switches from the top side without desoldering, once you know how they come apart? Just to confirm that we're both talking about the same thing, the switches on mine look like this, only the stems are bright yellow: https://deskthority.net/wiki/General_Instrument_Series_S950 Thanks in advance for any advice you can offer. Edited February 23, 2018 by Machead Quote Link to comment Share on other sites More sharing options...
Ed in SoDak Posted February 24, 2018 Share Posted February 24, 2018 The gray parts are locking tabs, press both in and the switch releases. How you release both tabs and lift up is the challenge! Maybe get one tab started and then the other. At least you only have one key to do. Well, two, with the replacement. Experiment on the junker keyboard first. It might be doable without opening up the console. -Ed Quote Link to comment Share on other sites More sharing options...
jjh76 Posted February 24, 2018 Author Share Posted February 24, 2018 Sorry, but in order to take them apart you will need to de-solder them. If you look at these closeup images: https://deskthority.net/wiki/File:General_Instrument_S95010_--_variants_table.jpg https://deskthority.net/wiki/File:General_Instrument_S95010_--_opened.jpg The metal bracket is sandwiched between the black top piece and the squarish tabs with the angled ledge. After de-soldering the switch you need to press those tabs in towards the center in order to get the switch out. (In my case, I ended up de-soldering the entire board so I was able to get at the tabs from underneath) The T shaped tabs on the other sides hold the cap on top of the switch. I tried at first to stick some small needles into the holes on the top of the cap, but couldn't get enough leverage to pry them open which is why I decided to just take the whole thing apart. Which didn't work out so well. After opening the switches and tweaking the little metal tab that gets pushed down by the plunger, the re-assemled switches tested ok using the continuity tester on my multimeter. However, after soldering it all back together there were half a dozen that stopped working again. Since I'm going to have to replace them anyway, I'll de-solder one tomorrow and snap some pictures of how I took them apart. With some of them still not working I didn't really feel like going through all that again so I did some searching and located a seller on AliExpress with a large stock of the switches, but won't know what condition they're in until they get here from china. https://www.aliexpress.com/item/SKCC-BJ0001-keyboard-switch-button-switch-reset-switch-micro-switch/32813803943.html Quote Link to comment Share on other sites More sharing options...
jjh76 Posted February 24, 2018 Author Share Posted February 24, 2018 (edited) Meh, pictures got rotated on upload. too lazy to fix it After removing the solder, use a pair of tweezers to squeeze together the locking tabs Pull up on the plunger, if the switch doesn't come out easily you might need to use a flathead screwdriver to pry it out ~ obviously, you can only do this with ones that are on the edge of the board. The switch removed from the bracket, and the micro-screwdriver that I used to pry it open Once I get one side free, I stick in a bit of wire to keep it from closing up again Repeat on the other side and you've got it open. Watch out for the spring, they can disappear on you if you're not paying attention. Edited February 24, 2018 by jjh76 5 Quote Link to comment Share on other sites More sharing options...
Ed in SoDak Posted February 24, 2018 Share Posted February 24, 2018 It's been so long, I'd forgotten about the soldered pins beneath. Thanks for correcting my oversight, jjh76! I use a desoldering iron that has an attached squeeze bulb for suction. Desoldering braid works if it's fresh or sand/scrape it a bit to show clean copper for the best wicking action. Some people like the separate soldapult style sucker along with their iron. Whichever method you use, adding a bit fresh solder often helps get the joint melted for easier removal. Probably best to use 60/40 lead solder (since that's what's on the old keyboards to begin with) and not the "lead-free" stuff. -Ed Quote Link to comment Share on other sites More sharing options...
Machead Posted February 26, 2018 Share Posted February 26, 2018 Wow, thanks, great work - very clear what I need to do now! It should be easy since the only key I need to replace is the left Shift, which is on the very edge of the board. Looking at the picture of the switch emerging from the board, it looks like there would be no way to open those T-shaped tabs in place (without desoldering) even if you had the perfect leverage/tool to stick in those four little holes, because the tabs are blocked in by the edges of the square hole in the metal tray that the whole switch assembly sits in, yes? I may not get to it until next weekend, but Im going to have my keyboard back to 100%. Thanks again. BTW, jjh76, Im in the Northfield area (about 30 miles south of the Twin Cities). And Ed, when I first got my 99/4A, I was a teenager living in SE South Dakota. Small world all around. Quote Link to comment Share on other sites More sharing options...
jjh76 Posted February 26, 2018 Author Share Posted February 26, 2018 You are correct, the tabs are blocked by the metal, didn't think to check for that myself Quote Link to comment Share on other sites More sharing options...
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