Leopold FC980m Replacement PCB (works w/VIA)

Ordered a custom Acrylic plate from Ponoko following the instructions in this thread: Tsangan plate design files

I wasn’t able to modify the DXF file for the mounting and edge cuts. Every time I touched or converted the file to SVG it would mess with the measurements. So I left those cuts out and made with a Dremel tool and a drill. The Dremel worked okay if you went on the slowest speed and really took your time (same with the drill although didn’t have to go quite as slow). I should have drawn a centerline across the plate and used that as a reference point when drilling. (I should have also spent more time on the DXF so I didn’t need to do those cuts by hand).

It is much lighter. I have tire weights and a poured silicon dampener in mine so its still heavy but noticeably lighter. Typing experience it is a softer bottom out which is what I was looking for. Sound wise I recorded a before and after. I am using Boba U4t switches unlubed (waiting on another part to go back and lube them). The plate is a fingerprint magnet.

Overall I am happy with it. PCB stabs are awesome, I was stuck with plate ones before and these are better IMO and easier to tune.

Regarding Heavy-9 case this plate will never be able to handle that mounting system. Its too thin and flimsy compared to the OEM steel one. However, I am hopeful a few 3d printed parts can be made to extend the load to the PCB and it can work (we will see hopefully I have one coming)

OEM Steel Plate

Acrylic Plate

Pictures (my phone couldn’t compensate for basement lighting and the blue mat, I need to stop taking pictures downstairs or get a real camera…)
https://imgur.com/a/AgR7X5u

Holding off on alternate bottom rows for a little bit. I have the designs ready but JLC is out of a couple of parts right now.

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Just realized I shared the post below on the Heavy-9 thread by mistake instead of here. Linking for prosperity.

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Hi everyone - just happened to stumble across NT980 and feeling a bit lucky to have come across this relatively recent thread. Thanks @Dave for the through guide, but I’m wondering if you or anyone else here ordered multiple and happen to have an extra to sell me. I’d rather not order 5 PCBs if I didn’t absolutely have to. Thanks!

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It’s probably for ESD protection

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I’m really into this! I want to do this mod and convert an ANSI board to ISO, but I have serious doubts about my ability to fabricate or otherwise get my hands on a custom plate.

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im just gonna put interest in GB for plate+hotswap pcb. i am aware other 980 hotswap options exist (FLESports 980) but i want one that is drop-in to the leopold plastic cases / possibly a heavy9 in the future.

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Offering my extra PCBs here if anyone is interested. Finally got around to reseating all the misaligned diodes (as discussed above) and tested in VIA – they are all 100%. PCBs will come already flashed with VIA as well as the connector soldered on. Will update this message if/when they’ve all been claimed.

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You could try using the Dremel on the existing plate and use a PCB stab. That way your cut wouldn’t need to be too precise. Even if it is a giant hole as long as you solder in the switches you should be good.

Heavy-9 with a non metal plate needs some different mounts otherwise it is too flexible. I am testing this setup now.

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You could try using the Dremel on the existing plate and use a PCB stab. That way your cut wouldn’t need to be too precise. Even if it is a giant hole as long as you solder in the switches you should be good.

I see. Alright, I guess I’m doing this then.

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Definitely interested in acquiring one of your extra PCBs. Let me know how much you’d like for one and we can sort out the details.

In my spare time, I am learning KiCad and how to read some of the nt-980 PCB details. Taking a closer look at the PCB connector to the original daughterboard I saw only half the pins are used. Which makes sense as only 1 of the 4 dip switches does anything with the nt-980. So the daughterboard can be bypassed by using JST 2.0 pin connector instead of the 10 pin original one. This might be useful to someone who doesn’t have or damaged their original daughterboard.

Alternate way to go into bootloader mode short the 2 holes with red arrows in the picture.

Note: I did learn the hard way to always triple check wiring before connecting. Was looking at the top view of the PCB in KiCad and didn’t realize it because zoomed in pretty far. This swiftly fried my extra PCB. Fortunately it was an extra so I wasn’t too upset. I did confirm with a different PCB and the original oem PCB it does work properly.

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Just found this thread. Super interested to do this myself. I also found a bluetooth adapter for the FC980C. What do you guys think about it working with the custom PCB?

@HonestIago
That controller is specific to the fc980c output and wouldn’t be compatible. There is a similar one for the fc980m (it’s occasionally on AliExpress) that someone might be able to finagle to work but would be hacky and expensive.

Bluetooth details is not something I know too much about but in theory you could get a generic keyboard to Bluetooth USB stick. Then bury most of it in the case.

Alt, in theory the MCU could be changed to accommodate Bluetooth. Beyond way beyond my still set.

Bluetooth has been a thorn in my side with my desktop (I tried multiple dongles). Less so on my laptop. When I want to use my keyboard I just want it to work right away without messing around. My headphones are bluetooth which I accept my daily turn Bluetooth off and back on daily and things mostly work ok.

I wish something like the Logitech unified receiver was open sourced and could be incorporated into non Logitech stuff. Maybe there is an open sourced rf transmitter and receiver out there.

For anyone who’s planning on removing the plate, after spending a bit of time trying to desolder this with a solder sucker and solder wick, this heat-and-slide method was the one that finally worked for me.

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I’ve can confirm that BT dongle is NOT compatible with this particular custom PCB. I got a yang 980M BLE and it’s running a custom YMK (closer to via) for BT and works incredibly well, but it can only work with the stock PCB.

Additionally, I noticed that the mini USB B and a 5 pin breakout. I’m not entire sure what’s that for, but I prefer to install a custom USB C port.

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I have been working on altering the open source design to learn a bit more and see were I could put my spin on the PCB design. All credit still goes to the original designer without that I wouldn’t know where to start.

  • Bottom row layout options
  • Stepped caps lock option
  • Labels for alternate layouts. Tried something a little different with shapes on the back to quickly ID the layouts quickly and easily (that is the idea at least)
  • Numpad Enter and Plus rotated
  • Added alternated LED location under num lock key
  • Additional Reset pins under delete key
  • Added second USB connection (JST 2.0 5 pin).
    Retained the original connector in the spirit of the original design. The alternate position can also be used with the stock case but eliminates the need for the Leopold daughterboards.
  • Converted most but not all the key positions to Kaihl hotswap. (The coper rings around the hotswap holes don’t do anything I just thought they looked :cool: )
    Why because I have switch and layout commitment issues. I thought this could potentially be a good compromise where I can have my cake and eat it too. I get mostly the better hotswap sockets yet I can still have the alternate layouts I want. When this works I can make a fully “normy” solder version for those less adventurous .

Thanks to @tinster4x4 @sarvopari & @Rico for helping me out and letting me bounce ideas off of them!!!

Next step is to work on the FR4 plate and place an order. I think I am about a week or so out. If anyone has any comments let me know and I will consider adding them. (Will also make a gitHub repo for this after I confirm it works). Due to part shortages, I have to solder the MCU so JLCs minimum order of 5 PCBs will probably work in my favor I mean I can probably do it right at least 1 out of 5 attempts :wink:

Layouts (originally supported split left shift and ISO enter added bottom row and split caps lock)
(Edit: Corrected typo in original)

Front:
**

**

Back

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electronically illiterate here: can i just confirm that v2 run of the pcb will be hotswap? what were you saying about

will the standard fc980 layout (first orange row with 1.25 Fn–i think that’s a typo in the diagram?) be hotswap? or do i have to ask you to do it if I order a pcb and plate? i’ve purchased a second 980M and would love to get a hotswap pcb and plate for it.

@insolentpotato
Good catch on the typo for the layout options (I corrected it above). KLE layouts can be a bit of a pain.

For the traditional FC980 layout 88 keys are Kaihl hotswap sockets 10 are traditional solder sockets. For my setup I am planning on soldering in Holtite sockets for the alternate layouts. So I can have the benefits of alternate layouts and hotswap (the Kaihl hotswap sockets are superior IMO rather then going all Holtite though I guess that is an option too if this idea doesn’t pan out)

This PCB shot from the back might be easier to visualize the different sockets.

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PCBs arrived. I got one working successfully! (Did NOT work on the first try and took many hours of frustration to get it working)

I will work on adding all the related files here over the next few weeks: nt-series/nt-980 at main · davek184/nt-series · GitHub

PCB:

  • All changes from original worked! (markings showed up nice)
  • Black PCB is way cooler looking then the green one
  • HASL-RoHS finish is noticeably uneven when compared to ENIG fortunately those were over the surfaces being soldered anyway
  • The mix match of Kailh hotswaps and through holes turned out nice
  • I need to to back and replace the JST connector it works but I have the proper part coming in the mail.
  • Going with 7u layout to start and see if I can get over the windows key muscle memory.

FR4 Plate:
Ooopsies

  • :man_facepalming: 2 of the mounting holes where slightly off. Not sure why I need to review might just change the hole shape in the future so I don’t need to worry about it.
  • Steps caps lock. Forgot to do this alternate position when lining up the dxf.

Good

  • 1 it works (in both Heavy-9 and after some Dremel and Drill action the stock case)
  • JLC made it with a black solder mask (their Gerber viewer was a bit messed up and gave a preview with no mask)
  • Its nice black mat finish I like way over the finger print magnet of Acrylic

^

Build Problems

Just including this here to show that things don’t always work out on the first try.

This whole process was very frustrating because in the back of my head I wasn’t sure if it was something I was doing wrong now or had totally messed up in the PCB design tweaks.

Things arrived and I was feeling pretty good. Installed the SMD components JLC didn’t have, resonator, MCU and ESD chip. Then tried to plug it in and nothing… After much testing around with a multi-meter everything appeared to be soldered correctly. So I started replacing components and still nothing. Asked/begged for help around and thought it might be the bootloader (or lack of bootloader on the ATMEGA32u4 chips. So built an ISP flasher with a pro Micro (followed this guide https://beta.docs.qmk.fm/using-qmk/guides/keyboard-building/isp_flashing_guide). Was able to decrypt the instructions and get it to flash the chip. Still not luck. Some more resoldering and nothing. I decided to try again with another new PCB and it worked.

Got through 50% of the switches and realized I messed up the plate steps lock key. Took everything apart again cut it and put it back together.

When I have more patience will go back and desolder everything and try again.

More photos here: https://imgur.com/a/jotWOC0

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Yea Dave! Nicely done, and way to stick with the troubleshoot until you got through. Mad props :slight_smile:

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