Making ZX Spectrum edge connector

If You are a little bit into retro computing and would like to experiment with ZX Spectrum computer outputs or make some extension board for it for some prototyping, then you need ZX Spectrum edge connector ( if we talk about original ZX Spectrums ). It is easy to make one by Yourself, just buy some regular 28x2P 56P 2.54mm 0.1" edge connectors on ebay and saw off both ends of it so they could be used for ZX Spectrum, done. https://www.youtube.com/watch?v=ZMIq1yrzVTo

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Repairing ZX Spectrum Kempston joystick

As recently I started tinkering with ZX Spectrum hardware, tested one old joystick I had. Up and right positions did not work during the games. Tested port reading with one simple program:10 LET x=IN 3120 PRINT X30 GOTO 10There was no reading in up and right position.I took apart joystick case and tested connection between PCB and plug - there was no connection for up and right wires.So, just took now DB9 female connector and soldered it instead of an old one that I have just cut away. 

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Fixing ZX Spectrum+ 48K (s/n S01-135100) video problems

So, this ZX spectrum was alive, but during testing with some games (for example game "Breakthrough"), I noticed strange video glitch in upper screen part:My guess was it is not video RAM related, but probably RF module fault. First decided to change all electrolytic caps on the board and see if it helps - it did not. Picture was the same.Then decided to check RF module - remove it and re solder all joints.After putting it back I did a check with the same game. It helped a bit, but…

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Another ZX Spectrum 48K

Maybe I got carried away.. but here is another non working rubber keyboard ZX Spectrum I got (s/n D01-257600).Its interesting regarding those serial numbers, some are 01 some D01. I really would like to know what do they mean, if they mean anything ? Found one site that has list of some serial numbers and has a form to submit more. Probably later I will submit them serial number of my ZX Spectrum machines. But now, back to this one.. On the outside it has some bruises and scratches, also…

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Repairing ZX Spectrum+ 48K

Another was ZX Spectrum+ 48K (s/n S01-135100). After turning it on could not see clear image (sorry did not take image of that picture). When I disassembled this device I found that it already had some changes, lower RAM chips were not original, it had some jumper wires soldered on PCB, transistor TR4 seemed like already replaced (at least someone did some soldering with it). Expecting the worst I started to check voltages (using this guide) and noticed that 12V is missing on lower RAM chips. When checked transistors TR5 and TR4 found that…

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Repairing and upgrading ZX Spectrum 16K

Going back into retro computing. Recently got little bit nostalgic and purchased two used non working ZX Spectrum machines. One was 16K, SN 001-201230.Tested some voltages using this guide and it seemed like everything is more ore less normal. Plugged it to TV antenna, tuned to channel 35, turned it on and as expected it didn't work. As usual biggest suspects were 4116 lower RAM chips:I had two options, first was to cut those IC`s out and desolder leads that were left using regular soldering iron. But doing that I would…

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