DSJR - I was all excited about the missing fifth wire (easy fix!) and then a bit of Google Image searching showed no other SL-65B with a fifth wire either-- boo. (Maybe it doesn't need a ground wire since the carrier is metal, rather than plastic like on my 40B?)
Does this sound like a good list of things to check?
- Disconnect cartridge
- Install cartridge sled and verify minimal resistance from each cartridge lead to corresponding solder joint on terminal block
- Verify continuity between tonearm tube and green ground wire/chassis ground
- Verify no continuity between cartridge positive leads and tonearm tube/green ground
- Measure resistance between each neighbouring pair of cartridge wires (B/W, W/R, R/G) to ensure no wipers are touching
Assuming this all checks out, I'm tempted to short together the existing tonearm wires, then attach new secondary wires to the terminal block, and connect the cartridge to those to test.
At this point I think it has to be one of three things:
- Bad ground connection at tonearm or terminal block
- Bad sled wiring
- Bad tonearm wiring (short or break in insulation)
I'm hoping that the tonearm just needs better grounding, but if I have to rewire the tonearm (I'm not against it; I like a new challenge) I'm tempted to bypass the sled connector altogether and just solder cartridge tags to the tonearm wires