Help needed via service manual or previous experience.

I had a problem w/original RCA connectors cutting in/out on my 1700.

Took the bottom cover off and found the connector board with RED hot, White  hot  and  1 common(shield).

My problem happened when I unsoldered the leads on the contact board along with 5 copper filament strands exiting from the tonearm. After I resoldered the interconnect leads , I just got hum from my system. (Idiot= didn't mark/identify the filaments when I unsoldered !)

I believe these filament strands are the actual signal from the pick-up/tonearm and I can't figure out which filament (s) go to which contact point . The only thing that differentiates them is the length . 2 = longest, 2 = medium and 1 = shortest.

Hope someone can help me in this as I am now on strike after 5 hours trying to get myself out of this mess.

 

Thanx, Ihor

 

 

Yes, these wires are the connection to the tonearm.

You can't tell them apart by their size, you rather need to take off the pickup and measure which one belongs to which pin.

If you look at the pickup fitting, you should see four pins. Those are from left to right: Right cold (=common), Right hot (=RED), Left hot (=White), Left cold (=common). The remaining (fifth) wire is the ground wire.

And pay attention: This is enameled copper wire - so only solder on the ends of the wire and check if there is a connection afterwards!

Hope this helps.

And welcome to Beoworld!

Hi and greetings from Canada,

Thank you for your reply and insight. I did figure out the wiring connection according to your explanation but unfortunately , 1/5 wires broke (Left cold-common) and I was hoping this wouldn't matter as the R cold-common is connected with the L cold-common at the junction terminals. No dice as there is hum from Left channel when hooked  up to the system.

While I was careful, it was a matter of handling repeatedly/too many times.

Inevitably, I'll have to get a service manual to try and disassemble the tone arm and rewire accordingly.

 

Regards, Ihor

Greetings from Franconia,

What you plan to do is just pure hell. Believe me, I've been there. Rewired three of those...you have to take the whole arm apart, scratch out the glue and that wires are really, really thin. Hardest part is getting it back together and reassembling it. And there's nothing about it in the service manual - the tonearm is listed as a seperate part and was replaced in whole. So better forget about that.

You are lucky it was that cable - I would suggest you just short the two common pins right in the pickup fitting or at the pickup itself. Far easier, isn't it? And it won't have any effect on the sound.

-Chris

Hi, Accordingly, what you described about taking off the tonearm..is hell! Through a more detailed inspection, the tonearm itself and all else fitted to the chassis-mechanism looks like a ROLEX with no room and tight tolerances. Taking note of your suggestion to short out the pins led me to the correct solution. I thought about my preamp and measured for continuity between the common terminals and ground(earth). Voila, it's the same path so I soldered 2 copper-strand filaments to the ground spade-lug on the Beogram pick-up shell and routed it neatly so the strand(s)would make contact with the cartridge pin (left-cold) once I fitted it back.As my luck happened to be that wire,my gateway from hell was open with great sound again. Anyway, the new interconnects seem to produce a brighter-crisper sound but that may be psychological because of my previous mess with loud hum etc... I've had this Beogram 1700 since late 1979 and it's never given me any problems so, after 30 years, I'm still the proud original owner. Also from an audio viewpoint,I can attest that the the latest refit SMMC20EN from SOUNDSMITH is superior to the original B&O MMC20EN. I did comparison blind testing with an audiophile and he came to the same conclusion. Many thanks to the folks at this BEOWORLD forum for ideas, solutions, and interesting talk > A Gros Merci from Montreal, Canada Ihor C.