Mz700 repair project

CRG
Posts: 22
Joined: Tue Feb 05, 2019 10:11 am

Re: Mz700 repair project

Post by CRG » Sat Feb 23, 2019 7:30 pm

With thanks to hlide then I will post the links to my current 2 videos in this repair series.

Part 1 is a quick tour around the machine, a tear down and repair to the power suppply
https://youtu.be/27fmWhkaNPE

Part 2 is tearing down, cleaning and trying to fix the keyboard
https://youtu.be/txZVdIi8Ab8

Part 3 will be the final clean, retro bright and rebuild then part 4 will be looking at some of the software.

Jo Even
Site Admin
Posts: 83
Joined: Wed Jan 17, 2018 9:28 pm

Re: Mz700 repair project

Post by Jo Even » Sat Feb 23, 2019 9:43 pm

CRG wrote:
Fri Feb 22, 2019 11:28 pm
I'm going to retro bright the keys and the case for my next step
Be very, very careful when retrobrighting the keys! I've seen several failed attempts at brighting 700 keyboards, the lettering seems to fade very quickly.
CRG wrote:
Fri Feb 22, 2019 11:28 pm
Jo Even, any chance you'd consider selling the 2 keys I'm missing from your keyboard with one missing (only if it is a spare of course). I need the right arrow and K keys.
Opened up the keyboard tonight, and unfortunately the plungers are not so easy to 3D-print. They are very finely detailed and also has a separate conductive part which can't be printed. However, the keys should be OK to print. I will make an attempt, my first key will be the missing F5 on my keyboard.

CRG
Posts: 22
Joined: Tue Feb 05, 2019 10:11 am

Re: Mz700 repair project

Post by CRG » Sat Feb 23, 2019 10:17 pm

When stripping the keyboard I noticed the shift keys use 2 plunger each but only 1 is actually required. I've taken 1 from each to replace my other 2 broken plungers so it's just the keys I need now.

I'll have a go at the retro brightening and see what happens. I've done an Amiga before and 1541-ii disk drive with some success. I was going to try a new method with a lower concentrate of peroxide this time so hopefully it doesn't effect the keys.

Jo Even
Site Admin
Posts: 83
Joined: Wed Jan 17, 2018 9:28 pm

Re: Mz700 repair project

Post by Jo Even » Sat Feb 23, 2019 10:39 pm

Jo Even wrote:
Sat Feb 23, 2019 9:43 pm
I will make an attempt, my first key will be the missing F5 on my keyboard.
First attempt, printing this right now:
MZ700 F-key 3D-printed.png
MZ700 F-key 3D-printed.png (34.35 KiB) Viewed 1000 times
And yes, you can use the "extra" plungers on the shift-keys in a pinch. However, they might become a little wobbly. I could try to 3D-print some "dummy" plungers to replace them.

CRG
Posts: 22
Joined: Tue Feb 05, 2019 10:11 am

Re: Mz700 repair project

Post by CRG » Sat Feb 23, 2019 11:17 pm

Fantastic work on modelling that key.

If you fancy the job of making me a K and right arrow key I'd gladly pay for it.

In terms of the broken plunger I was thinking again and the easiest option may be to recreate the top part of the plunger only then saw it off the base of the broken one and glue on the new. If you know what I mean.

Jo Even
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Posts: 83
Joined: Wed Jan 17, 2018 9:28 pm

Re: Mz700 repair project

Post by Jo Even » Sat Feb 23, 2019 11:26 pm

CRG wrote:
Sat Feb 23, 2019 11:17 pm
If you fancy the job of making me a K and right arrow key I'd gladly pay for it.
First test was as expected, it did not quite fit. The outer dimensions were almost perfect, but the plunger hole was a little bit tight. Will make a second attempt tomorrow. If it works I'll have a go at the other keys. However, don't expect factory looking parts. My 3D-printer is rather basic.
CRG wrote:
Sat Feb 23, 2019 11:17 pm
In terms of the broken plunger I was thinking again and the easiest option may be to recreate the top part of the plunger only then saw it off the base of the broken one and glue on the new. If you know what I mean.
Ok, so the plungers are just broken? Same as mine then, the top (Lego-shaped) part is broken off. Yes, I know what you mean. In fact, I have already modeled a replacement for the top part. However, I'm not sure if the 3D-printed part would be strong enough. We'll see tomorrow.

Edit: With a bit of fitting you might be able to repair the plunger using a bit of Lego:

Image

It's already almost a perfect fit, you just have to file it a bit. Should be much stronger than a 3D-printed part.

CRG
Posts: 22
Joined: Tue Feb 05, 2019 10:11 am

Re: Mz700 repair project

Post by CRG » Sun Feb 24, 2019 12:12 pm

I'll have to raid the kids lego box to borrow a few bits. Can maybe use a lego block as a temporary key lol.

Jo Even
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Re: Mz700 repair project

Post by Jo Even » Sun Feb 24, 2019 8:46 pm

So the 3D-printed F-key was a success :) I have started on modeling the arrow-key, but there was not enough time to finish it this weekend. I hope to have it finished and tested on Tuesday.

Jo Even
Site Admin
Posts: 83
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Re: Mz700 repair project

Post by Jo Even » Mon Feb 25, 2019 1:14 pm

First version.
MZ700 arrowkey 3D-printed.png
MZ700 arrowkey 3D-printed.png (11.7 KiB) Viewed 976 times

CRG
Posts: 22
Joined: Tue Feb 05, 2019 10:11 am

Re: Mz700 repair project

Post by CRG » Mon Feb 25, 2019 1:29 pm

Looks really good. I'll have a go with the lego tonight and see if I can get something sorted with the plungers.

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