I have purchased ZX Spectrum +2A to my collection and as with +3 decided to add a composite video out.
First what I did I made this RGB mod to get s-video out, by:
1. Removing the 12V from pin 1 by removing resistor R44 (should be the same for +2A, +2B and +3, and very close to the RGB connector).
2. Adding this circuit
Also detached audio from video by removing C24 and shorting from R46 to R56:
I got the video out and it seemed ok at first, but when doing self-tests the result was a washout picture:
ZX Spectrum +2A/+3 Schematic:Z70830
ZX Spectrum 128K video fixes and video cables:ZX Spectrum 128K video fixes and video cables
Some useful links: