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c-4000 repair question

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I got this C-4000 several years ago second hand. Opened it up to replace Power board caps. Someone modified the motherboard by cutting traces, modified power switch (looks to be in headphone section?), and jumped from power board to motherboard. In reading schematic, there is a difference between the original board and the later versions, I wonder Is this a factory/service mod? Has anyone seen? Main question is; do I put back to stock or try and recreate the modification, in which case I need to get signal to the motherboard.  The cut traces and bypass power switch are in image 3.


On first image, that white wire jumps to another ground line on the motherboard, (seemingly connected by the header), and there were jumpers soldered in to bridge the header. Unfortunately did not discover until disassembly. They seemed to connect to one (wrong) side of the volume pot.

Appreciate any insights. The unit has 1981 on the boards, and the unit included a preliminary users manual, with hand written notes.





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