🇬🇧 dk'tronics Keyboard for ZX Spectrum: Part 2 (Power On - NOK) [TCE #0605]
30Let's have a quick look at the Issue 4S board ZX Spectrum+ board that came with the keyboard. The ULA was missing as was one of the 4116 16kbit DRAM chips that make up the lower 16KB of RAM. I noticed that the composite video mod. had been done already. Looks like the board might've been used for spares so might not be in a good state.
I used one of vRetroDesign Charlie's vLA82s to replace the missing ULA and substituted a 4164 temporarily in place of a 4116.
https://www.vretrodesign.com/
Looks like some troubleshooting is required ...
Dave of Tynemouth Software has an interesting blog post about repairing an Issue 4S board:
http://blog.tynemouthsoftware.co.uk/2018/06/zx-spectrum-mystery-repair.html
00:00 ... Intro
05:34 ... Repairs done
06:25 ... Power on - NOK
07:10 ... Thermal imaging - CPU is hot!
10:47 ... Channel thanks & outro
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From Part 1:
Let's have a look at this keyboard & case for the Sinclair ZX Spectrum from dk'tronics. As with the Fuller FDS keyboard & case, the Speccy must be denuded for it to fit. This case is designed to also accomodate the Spectrum's Interface 1 (also denuded) which adds MicroDrive, RS232 serial and network support to the Speccy, similar to the Fuller FDS.
There's not much to it. The keyboard is okay, nothing spectacular. It has a lot of space inside which would allow your Speccy to breath a bit more, although you can also fit your power supply inside as well. It apparently came with a double-ended PCB that you could attach to the MicroDrive port on the Interface 1 to allow your MicroDrive cable to connect from outside.
The Speccy that it came with is an Issue 4S and is missing its ULA (not a major issue). It also has a reset button attached (I assume), although it's floating free rather than affixed to the case.
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