Jump to content
Email us at SERVICE@NELIONAUDIO.COM to schedule a repair or restoration. ×
Search In
  • More options...
Find results that contain...
Find results in...

Welcome to Nelion Audio

Register or login now and gain instant access to our features!

Vintage audio integrations and upgrades

Custom modifications

Reaching the best sound quality possible

c-4000 repair question


Recommended Posts

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.

IMG_2435.jpg

IMG_2435.jpg

IMG_2437.jpg

IMG_2438.jpg

Link to post
Share on other sites

Join the conversation

You are posting as a guest. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...