Need help fixing nerd tkl

[RoastPotatoes]

The pcb isn't in good shape and I need some information on how I can hand wire some of the non working switches. This is what I currently have working.
 

I was able to get some keys working by hand soldering, but I have been unsuccessful in understanding the matrix on the left side. The problem arose from the pads coming off during soldering so not all of the switch pins have made connections. This is why I believe hand soldering to be the best option.

Successful hand wiring:



Area that needs:



I have tried various configuration on the right side, but with no success. Hopefully someone might know how I can get this fully operational.

[pichu23]

Man that looks rough. I'm not sure if I'm much of a help but if you could get some wire and touch the 2 joints and see if it works.
If it does I guess you could solder the wire with the switch connections together like the ones that are working.
If it doesn't register then I'm not sure if I could help, maybe someone who's done this before could help.
Sorry buddy.

[suicidal_orange]

Looking at your pics the "fixed" side looks wrong - the pins you've soldered on Insert and Page Up are connected by a trace running along the row, and I don't see anywhere that links to the other rows on that pin.  Have you tried pressing multiple keys over there and looking for ghosting?  It might be right and if it works...

So, the other side!  Looks like you've taken out columns 1 and 2 and that should mean it's the diode part of the matrix, but I'm seeing possible breaks on the rows - it's already a mess and two connections is better than none so try adding the orange links.  I don't think they'll fix everything (and might not fix anything) but they look broken so leave them on.



Can you take a pic of the other side of the PCB?  It's clearly two sided so it's hard to work it out with only half the story.  Also, I can't see the pads on Esc - do they look ok?

It's not unfixable

[RoastPotatoes]

Thank you so much for the help. I will take more pictures. The problem is I can't see the front due to the plate. I have been looking for high res pictures of the front but none have really given clear enough images of the traces.

[RoastPotatoes]

Looking at your pics the "fixed" side looks wrong - the pins you've soldered on Insert and Page Up are connected by a trace running along the row, and I don't see anywhere that links to the other rows on that pin.  Have you tried pressing multiple keys over there and looking for ghosting?  It might be right and if it works...

So, the other side!  Looks like you've taken out columns 1 and 2 and that should mean it's the diode part of the matrix, but I'm seeing possible breaks on the rows - it's already a mess and two connections is better than none so try adding the orange links.  I don't think they'll fix everything (and might not fix anything) but they look broken so leave them on.

Show Image

Can you take a pic of the other side of the PCB?  It's clearly two sided so it's hard to work it out with only half the story.  Also, I can't see the pads on Esc - do they look ok?

It's not unfixable :)

I have tried what you said.

But still none of them work. I'm really not sure where to go from here.
Here is just a close up of escape:

[RoastPotatoes]

Man that looks rough. I'm not sure if I'm much of a help but if you could get some wire and touch the 2 joints and see if it works.
If it does I guess you could solder the wire with the switch connections together like the ones that are working.
If it doesn't register then I'm not sure if I could help, maybe someone who's done this before could help.
Sorry buddy.

Thanks for your input anyway. That is really what I am doing. I  pretty  much just did the other side on guesswork and it seems to be ok. But I will be trying until it works.

[suicidal_orange]

Oh a plate, that's not fun... I mapped the matrix on my Ducky with a plate on - pretty sure it was designed by someone on crack so it took many hours with a multimeter and touching pins with wires to see what worked.

Looks like both pads on your Esc are gone, the bottom one has a handily placed hole above the diode to connect to but the top pin is a mystery.  Also the bottom of the diode for Esc looks dodgy - can you make out what it's supposed to connect to?  Just looks like a big burnt mess from the pic.  If that heads off along the board (a trace does, might be LED related) that could be your biggest problem.

[RoastPotatoes]

Oh a plate, that's not fun... I mapped the matrix on my Ducky with a plate on - pretty sure it was designed by someone on crack so it took many hours with a multimeter and touching pins with wires to see what worked.

Looks like both pads on your Esc are gone, the bottom one has a handily placed hole above the diode to connect to but the top pin is a mystery.  Also the bottom of the diode for Esc looks dodgy - can you make out what it's supposed to connect to?  Just looks like a big burnt mess from the pic.  If that heads off along the board (a trace does, might be LED related) that could be your biggest problem.

Esc is a bit of a mystery. I belive it might connect to the tilde below it.

The diode could be a problem. I will look into this.

[suicidal_orange]

Yup - top of Esc goes down but that's still not going to make anything work as it's the far end of the trace from the controller, and Tilde doesn't work.

Looks like the top pin of Tab connects to the top of Caps Lock too?  The pic gets a bit fuzzy down there...

[RoastPotatoes]

Yup - top of Esc goes down but that's still not going to make anything work as it's the far end of the trace from the controller, and Tilde doesn't work.

Looks like the top pin of Tab connects to the top of Caps Lock too?  The pic gets a bit fuzzy down there...

I'll give that a go. This is the best photo I could find of the area.

[RoastPotatoes]

Yup - top of Esc goes down but that's still not going to make anything work as it's the far end of the trace from the controller, and Tilde doesn't work.

Looks like the top pin of Tab connects to the top of Caps Lock too?  The pic gets a bit fuzzy down there...

I the connnections for each switch seem to be ok. I connected them in a way they don't activate the right scan codes but they are working. I just don't know where to connect them.

[suicidal_orange]

If they're giving the wrong codes they aren't really working, it's all in the connections.  What key gives what code?  That gives you a clue as to what should be connected.  Also, can you take a pic of all the connections you've made in that area?  Easier than trying to remember multiple stages.

I'll switch to a sensible size screen shortly and have another look, hi-res pics aren't fun on a netbook )

[RoastPotatoes]

If they're giving the wrong codes they aren't really working, it's all in the connections.  What key gives what code?  That gives you a clue as to what should be connected.  Also, can you take a pic of all the connections you've made in that area?  Easier than trying to remember multiple stages.

I'll switch to a sensible size screen shortly and have another look, hi-res pics aren't fun on a netbook )

This is the current configuration.

I went a little overboard but I was going to switch out the wires for smaller ones once I got everything working.
The bottom row was just really an experiment. But when connected all along the bottom row, the the previously unworking keys show up as these:



Thanks for your continued help!

[suicidal_orange]

Which key is \| ? That is wired in in the ISO position so that's helpful.

[RoastPotatoes]

Which key is \| ? That is wired in in the ISO position so that's helpful.

1 registers as |\ when the bottom row is wired

[suicidal_orange]

Which key is \| ? That is wired in in the ISO position so that's helpful.

1 registers as |\ when the bottom row is wired

Makes sense - it's in the second column.

What's Q?

[RoastPotatoes]

Which key is \| ? That is wired in in the ISO position so that's helpful.

1 registers as |\ when the bottom row is wired

Makes sense - it's in the second column.

What's Q?

*
Right win

[suicidal_orange]

OK I had a proper look on a big screen - L-ALT and L-WIN are nearly connected but not - the trace goes to a small through hole just above L-WIN and if we trust the TKL in the borrowed pic is the same that goes up to the ISO key, so please disconnect that.

L-WIN to L-CTRL looks good from your first pic, and then it goes to another through hole.  This hole is in the blur on the borrowed pic and doesn't seem to be on the pics on Gon's site so I guess yours isn't a V2 board?

If this leaves you with all the keys not working again I think, judging by the diode pattern of connecting every other, the bottom of the diode for Esc should connect to the bottom of the diode for F2.

Wish I had the board here, would be so much easier if I could poke random things but there are too many ifs buts and maybes to type it out.

[RoastPotatoes]

OK I had a proper look on a big screen - L-ALT and L-WIN are nearly connected but not - the trace goes to a small through hole just above L-WIN and if we trust the TKL in the borrowed pic is the same that goes up to the ISO key, so please disconnect that.

L-WIN to L-CTRL looks good from your first pic, and then it goes to another through hole.  This hole is in the blur on the borrowed pic and doesn't seem to be on the pics on Gon's site so I guess yours isn't a V2 board?

If this leaves you with all the keys not working again I think, judging by the diode pattern of connecting every other, the bottom of the diode for Esc should connect to the bottom of the diode for F2.

Wish I had the board here, would be so much easier if I could poke random things but there are too many ifs buts and maybes to type it out.

I had a go but I'm still getting nothing. I think this is as you described. The Esc diode is connected to the bottom of F2 by a long piece of wire but this seems to have had no effect. Should Q be connected to L-Win. I can't tell for certain but it might be in the borrowed photo. It is a V2 board it has the marking. However, it might be a slightly different variant as it is the deskthority award branded one. But I'm not sure if there are any actual differences in construction.

[suicidal_orange]

Sorry for my disappearance, got invited out Saturday night and was out for my birthday yesterday.

I still can't see the crucial link we're missing so I think you're left with the tedious "poke and see what happens" method.  Touch a wire from the top pin of a non-working switch to the bottom pin of a working switch - if this outputs something you have signal going to the switch and it's the diode side that's the issue.

If you can find which switch to touch to get the right scancode you can solder a wire between the bottom of the broken switches diode and the bottom of the working switch's diode, but chances are there won't be anywhere as the diodes are on the columns.

If nothing is output try a couple of other working switches before deciding there is no signal - it's possible to hit an unused space in the matrix.

You can use the same method but going from the top pin of a working switch to the bottom pin of a broken switch. This should always output something so if it doesn't connect it to the diode - if that works you need to solder between the switch the diode.

Anytime you find something that needs soldering it's worth testing the other switches as it only takes one link to get a whole chunk working.

Hopefully Gon didn't do a Ducky as there are a couple of colums with only two switches on and these would have been impossible to find!

The other option is to find a friendly person who owns a working one they don't mind dismantling and a multimeter - continuity beeps are easier than trying to touch two pins while looking at a screen.

[RoastPotatoes]

Sorry for my disappearance, got invited out Saturday night and was out for my birthday yesterday.

I still can't see the crucial link we're missing so I think you're left with the tedious "poke and see what happens" method.  Touch a wire from the top pin of a non-working switch to the bottom pin of a working switch - if this outputs something you have signal going to the switch and it's the diode side that's the issue.

If you can find which switch to touch to get the right scancode you can solder a wire between the bottom of the broken switches diode and the bottom of the working switch's diode, but chances are there won't be anywhere as the diodes are on the columns.

If nothing is output try a couple of other working switches before deciding there is no signal - it's possible to hit an unused space in the matrix.

You can use the same method but going from the top pin of a working switch to the bottom pin of a broken switch. This should always output something so if it doesn't connect it to the diode - if that works you need to solder between the switch the diode.

Anytime you find something that needs soldering it's worth testing the other switches as it only takes one link to get a whole chunk working.

Hopefully Gon didn't do a Ducky as there are a couple of colums with only two switches on and these would have been impossible to find!

The other option is to find a friendly person who owns a working one they don't mind dismantling and a multimeter - continuity beeps are easier than trying to touch two pins while looking at a screen.

I am not sure If I am doing it correctly. But I haven't been able to get any usable results. I just end up looping back on myself after testing all of the other switches. The scan codes sent are always one column away.


Edit: The method I was using was the bottom of the non working switch  diode to the top of a working switch.

[suicidal_orange]

That means your diode side is good so that's something, but it also means you have the hardest bit to fix as the whole "column" is out.  There don't seem to be any traces coming off Escape and the controller is at the bottom so that makes sense, but there are no traces there either so they must be on the front.

Can you read the controller chip's model number?  If you can find a datasheet for it and find which are the IO pins you can poke them directly (controller to bottom pin), then once you've identified the right pin you can carefully scrape a bit of the white off the PCB and solder to the trace.  Assuming it's one that doesn't come up under the chip...

[RoastPotatoes]

That means your diode side is good so that's something, but it also means you have the hardest bit to fix as the whole "column" is out.  There don't seem to be any traces coming off Escape and the controller is at the bottom so that makes sense, but there are no traces there either so they must be on the front.

Can you read the controller chip's model number?  If you can find a datasheet for it and find which are the IO pins you can poke them directly (controller to bottom pin), then once you've identified the right pin you can carefully scrape a bit of the white off the PCB and solder to the trace.  Assuming it's one that doesn't come up under the chip...

So it is an atmega32u4 chip. I thought this was a generic chip but I seem to have found the datasheet. http://www.atmel.com/Images/Atmel-7766-8-bit-AVR-ATmega16U4-32U4_Datasheet.pdf
I also believe I have found the correct pin. For esc touching pin 1 to the bottom of the esc switch, activates the correct scan code. But I am not sure where to proceed from here. There is no visible trace leading to the pin. So does this indicate it is coming from below or the other side?

[suicidal_orange]

That's a common chip, not really a surprise

Pin 1 is an IO pin so sounds like you're good there, just need to find somewhere to to solder to.  You could go straight on the pin but I don't think your soldering skills/equipment are up to the task, it's very small so easy to bridge two pins.

I assume Pin 1 works for the other switches too?  You can take off all the wires on the top pins and if they work put short wires on, may as well do all of them to be safe.

Which way is the chip rotated?  There will be a link from somewhere on the end column(s) to the chip, if pin 1 is at the bottom of the board the trace will be running round the edge, if it's at the top it will probably be in the middle.  Any clues would be good, then it's back to the pics.

[RoastPotatoes]

That's a common chip, not really a surprise

Pin 1 is an IO pin so sounds like you're good there, just need to find somewhere to to solder to.  You could go straight on the pin but I don't think your soldering skills/equipment are up to the task, it's very small so easy to bridge two pins.

I assume Pin 1 works for the other switches too?  You can take off all the wires on the top pins and if they work put short wires on, may as well do all of them to be safe.

Which way is the chip rotated?  There will be a link from somewhere on the end column(s) to the chip, if pin 1 is at the bottom of the board the trace will be running round the edge, if it's at the top it will probably be in the middle.  Any clues would be good, then it's back to the pics.

The chip is at the bottom rotated clockwise. So pin 1 is pointed up towards the centre of the board. I will try to find the correct one as I agree soldering directly to the pin is likely to not go well.

[RoastPotatoes]

I did it anyway. I filed down my soldering tip so a  fine point and made do with what I have. It is currently working.

[berserkfan]

I must say that you, suicidal orange, are really awesome. I near blinded myself trying to figure out how to trace the PCB. Potatoes really roasted himself on this one. But now I know who to go to for help in future...

[RoastPotatoes]

I must say that you, suicidal orange, are really awesome. I near blinded myself trying to figure out how to trace the PCB. Potatoes really roasted himself on this one. But now I know who to go to for help in future...

I will have to agree with this. suicidal orange has been very helpful, more than I expected anyone to be. Thank you for your continued and dedicated help. It was very helpful.


And also https://youtu.be/Y6JnYnA9Tzo sorry there was no suicidal orange variant.

[RoastPotatoes]

Here is a small gallery of the finished product. http://imgur.com/a/qxBYr Thanks for your help!

[pichu23]

Oh it's working as it's intended now?! Great job suicidal orange and to roast potatoes, hopefully it will be the last time this happens :X

[suicidal_orange]

I must say that you, suicidal orange, are really awesome. I near blinded myself trying to figure out how to trace the PCB. Potatoes really roasted himself on this one. But now I know who to go to for help in future...

I'll try, but had it not been a corner pin this would have been really tricky.  Please buy a board the uses a Teensy (or equivalent) so it has big pins and I'll be happy to help

I will have to agree with this. suicidal orange has been very helpful, more than I expected anyone to be. Thank you for your continued and dedicated help. It was very helpful.


And also https://youtu.be/Y6JnYnA9Tzo sorry there was no suicidal orange variant.

No problem, just glad to get to see it's working.  Looks good from the outside too - you'd never know what horrors hide below.


Thanks for the video, didn't see that coming!  My birthday's not 'til Thursday but had to make use of the long weekend