Zenith Z-150 Restoration; Conversion


07 May 2019, 15:10

*This will most likely take me a few days at the very least because of how filty it is. Once completed, I will post more pics in gallery*

Day 1: The keyboard has arrived! There were only 2 photos of it on the listing so I could not see exactly how bad it was but to be honest it is much worse than I expected. The bottom is rusty and bent, the cable is cut (might not even work?), the plate is loose, the entire plate is covered in what looks like the fluff from a tumble dryer and it has LOTS of dirt in it (I'm pretty sure this was stored outside at some point, uh oh). Some switches feel like complete shit while others feel perfectly fine but I can't complain about green alps.
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close switch.jpg
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I've built a Teensy converter using the remaining original cable/connector and it works! Some keys don't register but after checking with a DMM, this is purely a hardware issue (I will be disassembling the switches to try and fix this)

Day 2
I have started desoldering the board. My iron is on its last legs and the sucker is practically dead which made this really painful and difficult. This is admittedly the worst desolder job I've done but I can't afford a new iron at this time. In a few instances, the pads have been torn from the PCB (poor heat control + 30 year old PCB don't go well together) so I will need to jumper those. I can't decide if I use the original PCB or handwire it when it comes to assembly.
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12 May 2019, 18:07

Finally got the PCB desoldered - what a pain. Some legs decided to randomly snap of while desoldering which was probably due to the liquid damage visible on the plate and PCB however there is enough material for me to solder to when handwiring.
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13 May 2019, 17:30

All the switches have been disassembled fully and the housings washed in warm soapy water to try to remove the strange white residue. After wiping with Q tips, the residue has barely come off so I will try with some isoporopyl alcohol when I get some.
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I've also worked on a custom layout which I am looking forward to finishing (if it lets me compile, that is)


04 Jul 2019, 11:43

The saga continues...
Sorry about the lack of updates - I had to put this project on hold for others such as a guitar that I needed to finish assembling.
The Isopropyl alcohol arrived today so I decided to start cleaning/lubing the switches. I first poured some IPA onto the switch housings which were all covered in that same milky substance in hopes of removing it. I mixed up some IPA and PTFE powder and put the sliders into the solution to evenly lubricate them (I used Delirious' method; thanks!) then set them aside to dry.
lubing sliders.jpg
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Since the plate had the same white residue, I tried scrubbing it with a sponge dipped in IPA so that I didn't have to waste time sanding the paint and repainting it. Sadly, the IPA did nothing at all so I'm going to try some 1000 grit sandpaper in hopes that it will preserve the paint.

I'll update later once the switches are assembled.


05 Jul 2019, 20:54

Nice, it will be interesting to see how it turns out.


06 Jul 2019, 15:20

Thanks, I've still not decided exactly what I want to do yet but I'll figure it out as I go along :D


02 Mar 2020, 19:09

Hi again!

Can't believe I left the project this long but uni work was (still is) a priority so I had to set some projects aside. I've finally decided to get back to work after an unfortunate incident with alcohol which ruined my main board leaving me with a grotty G80 as my daily driver. I'm somewhat glad I took time away from this because I had no motivation and it would have turned out rushed and not-so-clean had I kept going.

There's not a huge amount of progress to report since the last post however I've finished painting the back plate and recently got the switchplate painted. Here's a teaser:
Painted Plate.jpg
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Once the enamel paint has fully cured, I will install the switches and show it off in its current form. After that, all I need to do is hand-wire it and finally program a controller. My main concern is the rushed job of lubing the switches. I feel like I put way too much PTFE powder in and as a result the switches don't feel as smooth as they could. I don't know if I can be bothered to disassemble them and start over so hopefully they feel better inside a keyboard.

Hopefully I'll have an update before next week but don't hold your breath :D

User avatar
Gotta start somewhere

02 Mar 2020, 19:22

Great work, I love the look of these Zenith's.

Definitely sympathize with putting off projects due to life, my Unsaver sat disassembled for years.


02 Mar 2020, 19:29

Thanks! I hate putting projects off. I've also had to halt my music too which is sad but that's just how life goes. I'm glad I came back to this build since I ended up selling a Model F as parts because I didn't have time to finish it.


04 Mar 2020, 19:43

Finally got the switches back in the plate! now I need to decide if I handwire it or use the PCB + a converter. My issue with handwiring is that pulling the keycaps will result in the switches coming out. On the other hand, half of the traces are gone on the PCB so I may end up using the PCB but partially handwiring it...
test fit.jpg
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07 Mar 2020, 17:31

Half of the switches are soldered in but I'm having issues with 2 or 3 terminals being too short as they snapped during desoldering so I might have to bore out a few PCB holes. Sorry for the constant teasers but I've at least gotta show this off before I finish soldering (I know, seems a bit silly to put the caps on before soldering but how could I resist?).
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I've done an out-of-case typing test and it is honestly one of the nicest feeling boards I've typed on even considering that the switches were dirty and might have been over-lubed. Hopefully I can finish this project soon and finally have something that feels incredible to type on after all this time!

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