… or web spiders FTW!
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C64 fixing mayhem ended!
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</intro>
I always wanted to play with C128 DCR. This is a cool machine since it has all in one case – a desktop case.
It can work in three modes – C128 mode natively but can also boot to C64 mode and with a proper disk it can run CP/M software under its second processor Z80!
I’ve got one such machine. It was bought as “For parts not working” … as usual. Buying working hardware isn’t fun, is it? 😀
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It even had an original seal!
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The disassembly process started and almost instantly I knew what will require fixing.
Internal PCB of power supply was shattered. I was really surprised because this C128D had an original warranty seal on it, so how would one manage to brake it without opening it?
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A PCB was a bit dusty but it didn’t show any problems at first sight.
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Lolz
Now to a major lol in this post 😀
I was taking some pics while inspecting this motherboard and this is what I’ve found …
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I was like WTH!!! At first, I thought it was dead and dried up … except for the fact … it wasn’t! lol!
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Well, I’ve told him that I am sorry that I am taking away his home but since it was nice weather, I’ve taken it outside and showed him a nice spot for a new one. Hopefully, he is still there, hunting for mosquitos and flies lol 😀
Anyway, back to work. Internal PSU had to be fixed as the first thing to check if a machine works.
PSU
Puzzles time! 🙂
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The PCB is an FR2 type, so I’ve used cyanoacrylate glue to temporarily put it together.
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Once that was done, I poured epoxy resin on top to make it rock solid. I wanted to cover the largest possible area while avoiding more complex parts so only resistors and diodes were covered.
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With a PCB in a one-piece, I’ve started to remove the solder mask on the bottom part traces to prepare it for soldering.
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Then, I soldered on wires that connected all broken traces. At this point, I’ve also fixed several cold joints that were there too.
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With all the above done, I’ve mounted PCB back onto its chassis.
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The moment of truth aaaaaaand…
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It worked!! 😀
Keyboard
Ok, so when I knew it works, I could continue with refurbishing. As usual, I’ve disassembled the keyboard, cleaned it off, and retr0brighted it along with the rest of the case.
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The results were more than satisfying.
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JiffyDOS
Now, with everything in place, I could start working on a JiffyDOS mod.
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You can get JiffyDOS on a Retro Innovations website.
I still have a lot of blank Winbond 27C512 flashrom chips so for my mod, I’ve decided that I will need only an image and will burn it into flashroms myself.
At first, I thought that I will need two flashroms, like in a flat C128.
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However, It turned out that C128D uses only one socket for ROMs so I had to rebuild my ROM image chain and burn it all again to a single chip.
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I’ve put a switch on a side of a case, next to a keyboard connector.
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Video add-on
I’ve also connected a nice device made by Pyrofer already covered in a post with C128 mods. In short, It allows using 80COL mode via S-Video.
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Finally some tests 🙂
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That’s it! I finally have a working C128 DCR!
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OUTRO
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Nice look at that D C R C128 repair, mine has worked fine for years, but just bought springs to rebuild the keyboard from you,thanks.I’m also restoring a C64C, and flat C128
Great stuff! good to hear another machines are being fixed and used! ;D
Cracked PCBs were quite common on electronics back in the day. Those heavy transformers could easily crack a PCB if handled without care.
Indeed! I was just really surprised 😀