Please feel free to move/delete this post if it's in the wrong place but while looking for another item, I came across this which could be of great use to anyone messing with the hardware:
https://www.esocop.org/docs/service.manual.cpc6128.ctm644.gt65.pdf (https://www.esocop.org/docs/service.manual.cpc6128.ctm644.gt65.pdf)
There's already a section for it in the Wiki. I think that one is there as well: http://www.cpcwiki.eu/index.php/Service_Manuals (http://www.cpcwiki.eu/index.php/Service_Manuals)