ZX Spectrum Repair – Composite Video Mod

Required Tools

Soldering Ironhttps://www.rapidonline.com/Weller-T0053298399-WE-1010-Soldering-Station-Set-230V-85-5614
Desolder Wickhttps://uk.farnell.com/mg-chemicals/425-ns/desoldering-braid-1-5m/dp/2903896

Now we have checked all the values before we plug it into our TV for testing we are going to do a composite video modification. This will enable us to plug the Spectrum into a modern TV using composite video, the old RF technology that was used has not been part of a modern TV for many years now.

It is a simple modification with a very simple solder requirement.

First locate the modulator box on the top left of the Spectrum and prise off the lid, it will easily come off.

On the left hand side of the box you will see two holes with wires poking out going onto the board. We are going to desolder these wires from the board.

Turn the board over and find the two relevant solder points, put some braid on top and heat your iron to 350 degrees.

I really recommend Superwick, I have used a large amount of different wicks and the difference between this and everything else is huge, it makes the job so much easier. Put the iron on top of the wick and you will see the solder be sucked up as it heats up.

Keep doing this until the holes are clear, you can then flip the board back up and remove the wires from the holes. You can wrap these on the casing so you can revert the machine to factory condition in the future if you want to.

Now find the wire soldered to the connector coming out the back of the spectrum and use your iron to melt the solder while using tweezers to move this away

You can now thread a wire through the empty left hand hole on the side and solder this to the connector you just desoldered a wire from and into the top hole on the board you removed a wire from earlier

Solder the new wire to the jack 
Solder the wire here