Add LED to an XEGS keyboard?

[ultrasteve]

I have a new old stock XEGS keyboard that I'm considering putting in to my 65XE or 130XE, but it doesn't have an LED attached. I know I can add a 3mm one by bending the legs, but do I need to fit a resistor anywhere, or will it be obvious how I need to fit it? I'm competent with a soldering iron, but have no real electronics knowledge, so an easy to follow set of instructions would be great if anyone has one?!

 

Thanks in advance.

[TXG/MNX]

You also got an issue with the option and other button they are on the xegs case just buy a broken 65xe,130xe or 800xe these all have the same kbd.

[ultrasteve]

The keyboard I have has the plungers present, so I believe I can take the function keycaps from the existing board and use them?

[gargoyle]

I have a new old stock XEGS keyboard that I'm considering putting in to my 65XE or 130XE, but it doesn't have an LED attached. I know I can add a 3mm one by bending the legs, but do I need to fit a resistor anywhere, or will it be obvious how I need to fit it? I'm competent with a soldering iron, but have no real electronics knowledge, so an easy to follow set of instructions would be great if anyone has one?!

 

Thanks in advance.

I am not familiar with the XEGS keyboard's innards but it seems to me it is possible to add a LED relatively easily. Just get a standard 3mm led, solder a 100-150 ohm through-hole type resistor (1/4watts) to the positive leg of the led (longer leg), find the 5v and ground rails on the keyboard PCB, solder the led's negative leg to the ground, positive leg (one with the resistor) to the 5v rail, You may need to use wires depending on where you want to make the led hole on the cover of the keyboard. Drill a 3mm diameter hole on the cover, insert the led and secure it with hot glue from behind and voila you have a keyboard with LED.

 

And electronics gurus out there, If i missed something or made a mistake somewhere in the above description, please don't hesitate to correct me.

Edited January 20, 2017 by gargoyle

[ultrasteve]

I am not familiar with the XEGS keyboard's innards but it seems to me it is possible to add a LED relatively easily. Just get a standard 3mm led, solder a 100-150 ohm through-hole type resistor (1/4watts) to the positive leg of the led (longer leg), find the 5v and ground rails on the keyboard PCB, solder the led's negative leg to the ground, positive leg (one with the resistor) to the 5v rail, You may need to use wires depending on where you want to make the led hole on the cover of the keyboard. Drill a 3mm diameter hole on the cover, insert the led and secure it with hot glue from behind and voila you have a keyboard with LED.

 

And electronics gurus out there, If i missed something or made a mistake somewhere in the above description, please don't hesitate to correct me.

Thanks gargoyle, much appreciated! My skills are going to fall over with the bit in bold above - I have a multimeter, but wouldn't know how or where to start with finding the 5v and ground?!

[gargoyle]

Thanks gargoyle, much appreciated! My skills are going to fall over with the bit in bold above - I have a multimeter, but wouldn't know how or where to start with finding the 5v and ground?!

 

Ok I took apart my XEGS keyboard. Inside the case is an exact XE keyboard, complete with a small red LED on the lower left side, the 3 plungers for the START/SELECT and RESET have no key caps, as those keys are re-implemented inside the XEGS case. The LED however is non-functional (as you already know there is also no LED hole on the XEGS keyboard cover). Also the keyboard connector does not have the necessary connection to illuminate the LED. Now, if all you want to do is to use the XEGS keyboard on your 130XE, you can just do a direct swap as the actual keyboard is exactly the same as the 130XE's original keyboard (unless yours somehow doesn't have the red LED already included).

 

Once the keyboard was disassembled, I took the opportunity to add a functional LED to my XEGS keyboard. It is easier to add a new LED then to try to make use of the existing one, so I went ahead and made the modification. Attached is the photo of the connection points for the LED (on the XEGS keyboard PCB), the other photo shows the end result.

 

This may or may not answer your question as at this point, as I am not sure if you wanted to know the potential LED connection points on the XEGS keyboard PCB, or on your 130XE motherboard. If its the latter, tell me and I'll get back you with that info.

 

 

[ultrasteve]

 

Ok I took apart my XEGS keyboard. Inside the case is an exact XE keyboard, complete with a small red LED on the lower left side, the 3 plungers for the START/SELECT and RESET have no key caps, as those keys are re-implemented inside the XEGS case. The LED however is non-functional (as you already know there is also no LED hole on the XEGS keyboard cover). Also the keyboard connector does not have the necessary connection to illuminate the LED. Now, if all you want to do is to use the XEGS keyboard on your 130XE, you can just do a direct swap as the actual keyboard is exactly the same as the 130XE's original keyboard (unless yours somehow doesn't have the red LED already included).

 

Once the keyboard was disassembled, I took the opportunity to add a functional LED to my XEGS keyboard. It is easier to add a new LED then to try to make use of the existing one, so I went ahead and made the modification. Attached is the photo of the connection points for the LED (on the XEGS keyboard PCB), the other photo shows the end result.

 

This may or may not answer your question as at this point, as I am not sure if you wanted to know the potential LED connection points on the XEGS keyboard PCB, or on your 130XE motherboard. If its the latter, tell me and I'll get back you with that info.

 

20170124_011208S.jpg

 

20170124_231028S.jpg

Thanks Gargolye, very much appreciated I'm currently undecided between adding an LED to the keyboard and putting it inside the 130XE, or just replacing the mylar in the existing 130XE keyboard. So to answer your question, I would be taking this XEGS keyboard and adding an LED to it via the 130XE motherboard if I chose the former route. Sorry if I complicated things initially!

[gargoyle]

Thanks Gargolye, very much appreciated I'm currently undecided between adding an LED to the keyboard and putting it inside the 130XE, or just replacing the mylar in the existing 130XE keyboard. So to answer your question, I would be taking this XEGS keyboard and adding an LED to it via the 130XE motherboard if I chose the former route. Sorry if I complicated things initially!

 

So that means your XEGS keyboard doesn't already have a LED unlike mine, hmm now I wonder if my XEGS keyboard innards were swapped with an XE equivalent??

 

Can anyone tell me whether the standard XEGS keyboard does include a LED or not?

[ultrasteve]

Well, this was sold as a new-old stock XEGS keyboard, and the one that is in my XEGS currently doesn't have an LED either! At least I didn't remember seeing one! I have a long list of things I need to do with my XEGS / 130XE so I'll try and find a day soon to get them all done and post some pics at the same time!

[gargoyle]

Well, this was sold as a new-old stock XEGS keyboard, and the one that is in my XEGS currently doesn't have an LED either! At least I didn't remember seeing one! I have a long list of things I need to do with my XEGS / 130XE so I'll try and find a day soon to get them all done and post some pics at the same time!

 

Yes, apparently my XEGS has an XE keyboard in the keyboard case. I found a thread in the forum and seen an original XEGS keyboard innards, there is a small hole on the XEGS keyboard where there is a LED on the XE version.

[ultrasteve]

I took my 130XE keyboard apart this morning. The connector on the mylar is a bit knackered, so I'm going to ditch it. The LED is not soldered to anything, is that right?! The legs have two rubber grommets on them, which look as if they just touch on to the contacts of the mylar. Are the legs of the LED touching the tracks on the mylar how it gets its power?!

This new old stock XEGS keyboard is what I'm going to use on my 130XE. The case has the two insets for the rubber grommet things, but are they there just to hold the legs of the LED? If so, I guess I could use two tiny blobs of Sugru to do the same thing. But what kind of LED do I need (power, etc.).

Thanks for all of your help.

[Bryan]

You cannot use the START/SELECT/OPTION keys without rewiring the whole thing because those keys go to GTIA instead of the Pokey keyboard matrix and they're not included in the 15-pin cable.

[ultrasteve]

So you're saying the Mylars in them are different too?

[Bryan]

So you're saying the Mylars in them are different too?

No, I'm saying that part of the mylar doesn't connect to anything because the wires aren't in the cable.

[ultrasteve]

Ah, got you. OK. But when I say an XEGS keyboard, I mean the keys and mylar that live within the housing, so the mylar connector would still be going direct to the 130XE motherboard. I may have confused things by mentioning that it came from an XEGS - I believe it to be the same keyboard, it just doesn't have the Option keycaps, but I can transfer them from my 130XE anyway. I've attached a picture of the back of the keyboard with mylar intact, and one of the gap where the LED goes.

 

So my original question stands I guess, could I put an LED into this gap, and if so, what kind/voltage etc. does it need to be.

 

[Bryan]

I believe it's a pretty standard 3mm LED. You can calculate a resistor value for it here:

 

http://led.linear1.org/1led.wiz

 

The LED will have a rated voltage drop and current value and you won't need full brightness so you can use a mA value below that. I believe the 65/130XE uses 1K ohms. This probably prevents heating of the painted mylar traces as well.

 

There will probably need to be some kind of interface material since the LED's leads would scratch the paint on the mylar.

[ultrasteve]

OK, cool, thanks! The one in my 130XE was just touching the traces, so maybe that's how they were mad?! I'll fit one in and see what happens! Thanks for your help, I'll post back when I've tried it out.

[Bryan]

If you look at this pic, I believe there are two carbonized rubber dots to connect the leads to the mylar.

 

[ultrasteve]

Yes, I have those in my 130XE keyboard. So is it imperative that I use those to avoid scratching the traces?

[Bryan]

Yes, I have those in my 130XE keyboard. So is it imperative that I use those to avoid scratching the traces?

The paint isn't very durable and even a small scratch could render it inoperable. You might get by with a couple small blobs of aluminum foil. I think you can get conductive rubber from hobby places like Sparkfun or Adafruit. You might be able to harvest some from something with rubber keys like a remote control or calculator.

[ultrasteve]

Oh, great idea, thanks! I'm sure I've got a remote control kicking about that is broken - I didn't even think of that, thanks!

[Bryan]

You're welcome. Usually only part of the rubber is made conductive so it may take some experimentation.

[ultrasteve]

I did exactly that, scavenged some contacts from an old joypad. BUT - using a brand new mylar that I got from Best Electronics, either with or without the LED and rubber in place, when I turn the 130XE on I get a blue screen and a single, high pitched beep, a rectangular cursor block, and nothing else. I've seated and reseated the connector multiple times, sometimes I get a totally garbled display, but most times as above. Does that point to a defective mylar?! Confirmed the 130XE working fine with the new old stock keyboard, so I know it's not a problem with the machine.

[Bryan]

Does it sounds like what happens when START is held at power-up?

[ultrasteve]

Yes, exactly those symptoms. I took it apart again, reseated the rubber and LED, and cleaned off the contacts on the mylar where the Start button presses, and it is working now - do you think it was just something on the contact or trace? It was a brand new out-of-the-packet Mylar from Best.

 

EDIT: I'd only put the four corner screws in to the keyboard backplate when I tested it. I've just put the rest in and I'm back to the Start button being pressed problem. Something must be touching those contacts?

 

EDIT 2: Undid screws around option keys, tried again, worked fine. Left connector cable in place, did screws up, worked fine. Maybe it's just a dodgy edge connector - it is VERY tight to put in.

 

I any case, it all seems to be working, so this will stay as my spare, or possibly make its way into my 65XE.

Edited April 2, 2017 by ultrasteve