Apple ii plus 's' key not working

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Apple ii plus 's' key not working

Hello everyone!

 

Last weekend I picked up an Apple ii plus from someone on craigslist and I believe I got a great deal on it. It came with a working hard drive, a Zenith monitor, hand controllers with the original box and another controller with a joystick and two red buttons on it along with a bunch of manuals and some software for it all for $100. When I came to pick it up, the owner was showing me that most keys were typing incorrectly, but when I purchased it and drove back home and fired it up, all the keys began working fine except for the 'S' key. It just does not work at all. I had desoldered it and examined the key by cracking it open and looking at the copper trace on it, but it looked fine. I desoldered the 'A' key next to it and put the key in the place of the 'S' key and again it was not working. So if it's not the key, then what else could it be? How do I go about determining another cause for it? I'm not great at electronics, but I can solder/desolder lol

 

Thanks!

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Since the rest of the

Since the rest of the keyboard seems to be working, you probably have a broken trace or via near the S key. Look carefully for a crack in one of the traces near the switch. Better yet, use an ohmeter to check for continuity across each trace and via connected to the S key switch. Once you locate the open circuit, you can use a small piece of wire to bridge it.

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jeffmazur wrote:

[quote=jeffmazur]

Since the rest of the keyboard seems to be working, you probably have a broken trace or via near the S key. Look carefully for a crack in one of the traces near the switch. Better yet, use an ohmeter to check for continuity across each trace and via connected to the S key switch. Once you locate the open circuit, you can use a small piece of wire to bridge it.

[/quote]

 

Oh, I appreciate that info! When I get a moment to open it back up again, I'll use my multi meter and set it to Ohms and try to figure it out. Thanks!

 

 

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I'm bringing this thread back

I'm bringing this thread back to life hoping I can get some new answers. I wanted to let everyone know I'm a dolt because I once again tried to open up the Apple II Plus, desoldered and swapped keys with the 'S' key to see maybe my luck might have changed, but it changed for the worse as I plugged the keyboard back into the motherboard upside down and now I only get the letter ' U ' and the character ' [ ' for every key I press. I must have blown out some IC's. I contacted a seller on eBay about replacing the keyboard, and it turns out that he said I most likely blew out some IC's on the daughter board. He said replacing the encoder board on the keyboard should fix the issue, but now that even though the keys are all whacked out, I'm still unable to get any detail out of the 'S' key on the screen. The traces look clean and when I swapped out keys, it wouldn't help. I just find it a shame that I will have to pay nearly double what I paid for the whole computer just to get a working keyboard. The seller mentioned that I most likely have an older Datanetics keyboard or a NON RFI since I was able to desolder the keys and he mentioned these are the best kind to have. Just a shame...lol

Could I just replace the IC's on the encorder board to get it back to typing as it was before without having to wait for someone to sell the encoder board? I'm pretty good at soldering/desoldering, just shit with electronics in general lol. I just don't know which IC's they are...

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I'm confused a bit right now.

I'm confused a bit right now.  

Are you saying that nothing works properly on that keyboard now, or Just the "S" key again?

 

If everything works except the "S" key you can try shorting the two contacts under the key switch and that should generate an "S".

Also, if you de-solder the key switch you should be able to get continuity between the two pins using a multimeter when you press the key, and open circuit when you release it.  Both states are important.

 

You should also check the connection of the daughter card to themain keyboard PCB.  Although if there was a problem with the daughtercard or the keyboard encoder chip was flakey (unlikely) then you'd have more issues than just the "S" key.

When you follow the traces from the "S" key ont he main keyboar PCB, you should be able to get continuity between the two pads of the "S" key and whatever they're leading to - an adjacent key and maybe the encoder's connection header.

 

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talos wrote:I'm bringing this
talos wrote:

I'm bringing this thread back to life hoping I can get some new answers. I wanted to let everyone know I'm a dolt because I once again tried to open up the Apple II Plus, desoldered and swapped keys with the 'S' key to see maybe my luck might have changed, but it changed for the worse as I plugged the keyboard back into the motherboard upside down and now I only get the letter ' U ' and the cha

Please send a photo of the exact keyboard to me. I can help further, but not without knowing the exact model. 

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As a followup, yes, you blew

As a followup, yes, you blew the encoder, but there are several encoders used depending on the KB model. 

 

If you have a mech with the early DC51 switches, I might be willing to straight trade it in its present state for a model with the later switches, as I have several of those in fully working order, so that I have more spare parts for that KB model. 

 

I should however, have encoders for both the early and late boards. 

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Thanks for the replies! Sucks

Thanks for the replies! Sucks I blew out the encoder board. I've attached photos of the keyboard. Turns out it's a Datanetics B Rev 1. Here are some photos:

 

https://imgur.com/a/MPwnPiw

 

 

 

 

 

 

 

 

 

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talos wrote:Thanks for the
talos wrote:

Thanks for the replies! Sucks I blew out the encoder board. I've attached photos of the keyboard. Turns out it's a Datanetics B Rev 1. Here are some photos:

 

https://imgur.com/a/MPwnPiw

 

 

LMK if you want to trade it for the later model. If not, I have one spare encoder sub-board, but that won't fix your S key. The keyswitch that you have is simply dead: The DC51 switches cannot be opened to service, and are getting hard to acquire in operable order. (Having it for spare switches for my ][ is why I would trade a working later KB for that one.)

 

I could also restore and repair that mechanism if you are in love with it, but that would be costly, too. 

 

 

 

 

 

 

 

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I might be interested to

I might be interested to trade. The whole reason I got this computer was that I wanted to mess around with using an acoustic coupler to go on the internet lol. I have 3 different acoustic couplers now since some work and some dont. I also purchased a Lear Siegler ADM-5 the same day I got this Apple II. You can see here how I initially tried to get the acoustic coupler to work with the terminal:

 

https://www.youtube.com/watch?v=o6Ll4EgnzMU

 

But for the Apple, I have no idea how to get it into a terminal mode and use it with an acoustic coupler. I purchased a serial card from ebay and figured to connect the coupler to that serial card, but I'm pretty sure I need some kind of floppy disk with a terminal program on it probably for it to work. Would you happen to have an idea how I can do that? And I would obviously need the 'S' key to work since many words require the 'S' to work. This board is pretty much useless to me, especially now since I fried the encoder board lol. The switches themselves need some sort of cleaning as they feel "rusty" as I press down on them. I'm sure you have some experience in that area. 

 

I don't think the keyswitch itself is dead, because I desoldered a completely different key from the opposite end of the board, like the 'L' key, and put it in the place of the 'S' and it still wasn't picking it up. Like I mentioned, I know how to solder/desolder, but I haven't figured out how to locate an issue on the board and fix it. The traces look clean, so I'm lost there. Easier thing for me would be to swap out the keyboard. 

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If the keyboard ribbon gets

If the keyboard ribbon gets plugged in backwards, it fries the 74LS04 on the encoder board. Replace that and test.

 

Larry G

 

 

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retrogear wrote:If the
retrogear wrote:

If the keyboard ribbon gets plugged in backwards, it fries the 74LS04 on the encoder board. Replace that and test.

 

Larry G

 

 

 Looks like Microcenter has them in stock near me. I'll try it out! Thanks

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WiFi-Modem that works with Apple ][
talos wrote:

But for the Apple, I have no idea how to get it into a terminal mode and use it with an acoustic coupler. I purchased a serial card from ebay and figured to connect the coupler to that serial card, but I'm pretty sure I need some kind of floppy disk with a terminal program on it probably for it to work. Would you happen to have an idea how I can do that? And I would obviously need the 'S' key to work since many words require the 'S' to work. This board is pretty much useless to me, especially now since I fried the encoder board lol. The switches themselves need some sort of cleaning as they feel "rusty" as I press down on them. I'm sure you have some experience in that area. 

  

I do not know much about acoustic couplers and the Apple ][, but I did recently have success with the WiFi-Modem (https://www.tindie.com/products/theoldnet/rs232-serial-wifi-modem-for-vintage-computers-v2/) for about $35 on my Apple //c. 

I took my ADTPro cable (Din-5 to DB-9 female that connected to my USB to DB-9 male cable on my Mac) and put a gender changer and a "null modem" adapter to convert it back to being a modem cable that works great with the WiFi-Modem.

 

I use Apple Access II software that I found on one of the Apple ][ software download boards.

 

Historically I used ASCII Express, but it was a very complicated program and until I can find a manual to remind me how to use it, Access II has been working fine for connections to BBS' for me.

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talos wrote:retrogear wrote
talos wrote:
retrogear wrote:

If the keyboard ribbon gets plugged in backwards, it fries the 74LS04 on the encoder board. Replace that and test.

 

Larry G

 

 

 

 Hey Larry! Thanks for the tip! I ran to Microcenter and swapped out the 74LS04 and I got some functionality back! Much better than before since every key was producing either a 'U' or an ' [ ' but now I have more keys, but some keys produce other keys. If I press 'C' I get an 'A', but 'A' gives me an 'A', a 'T' gives me a 'T'. So some letters aren't being produced while others are working fine. Should I swap out other IC's on the board like the DM74LS00N IC's? There are 2 of them next to the NTE74LS04 that I swapped out. 

 

Thanks!

 

Grant

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talos wrote:talos wrote
talos wrote:
talos wrote:
retrogear wrote:

If the keyboard ribbon gets plugged in backwards, it fries the 74LS04 on the encoder board. Replace that and test.

 

Larry G

 

 

 

 Hey Larry! Thanks for the tip! I ran to Microcenter and swapped out the 74LS04 and I got som

Send a PM to me if you want a swap. I need the 51 switches, and I have other KBs on hand that work. Sounds to me like you blew more than one IC. I can probably diagnose and fix it in the future, but at present, I need it for parts. If you want to swap it, send a PM to me. I do need to verify that it uses 51 switches first--or else it is useless to me. 

 

WRT Terminal Emulation, I used to use ProTerm, but IDK if you can run that on that machine. The oldest versions, perhaps???

 

 

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replace the 74LS00 at B4. The

replace the 74LS00 at B4. The one right next to the LS04. It's also in the keycode matrix. The other LS00 is not but you could get a spare in case the shift or control keys don't work, then replace it as well

 

Larry G

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