No output from Turntable any ideas?

apphd

Hi long time since posting, but anytime I have a question I find CP to be a good starting point. Sorry for the length of this but here goes. I recently decided to get my Dual CS 5000 back into action. Installed a new belt and it spins up and locks on speed. But I get no, to very little output. I recently added an ART USB phono plus phono amp. Lack of phono inputs on a receiver upgrade was one of the reasons the TT has been in storage. Decided on the ART with the plan on digitizing my LPs. I had a Shure cart on it with low time before storage. Replaced with the original Ortofon OM20 that has high time but was working when I installed the Shure. Still no go. Disconnected the cart and rang out the R L and grounds from the tone arm to the RCAs and the ground lead from lug, to where it connects to a plug inside the plinth. Found no opens, or shorts from R to L or signal to ground. Also cleaned all connection points with some isopropyl alcohol while I was at it. Still nothing. Finally borrowed a friends TT and verified the phono amp and AVR are working, so it is definitely an issue in the TT. I plan on getting a stylis and or cart, but before I do I want to get some sound out of it before spending the cash on it.
Any ideas on a next step for troubleshooting? Thanks in advance.

[Deleted User]

In looking at the table's service manual there does seem to be an optically controlled end of record circuit. If you have a volt/ohm meter (VOM) you could check the continuity between the output RCA plugs and the cartridge connecting pins with the arm in the position it would be in mid record play. In all likelihood the tonearm mutes left and right outputs when the end of record lifts the arm.

jeremymarcinko

Perhaps the cartridge isn't creating enough voltage. Moving magnet cartridge?

apphd

Sorry forgot to include, it is a MM cart. But I am getting this with 2 different carts. The Shure and the Ortofon. Anyone know for the ground where it might go from the connector inside the plinth.

skrol

I didn't catch what the answer was... I was thinking that TT may mute the output when the auto-return is activated (semi-automatic). If so, that may be malfunctioning (dirty contacts?).

There looks to be good info for that TT on Vinyl Engine http://www.vinylengine.com/library/dual/cs-5000.shtml including a service manual.

apphd

Stan I haven't thought about that. Never noticed if it muted at the end or not. after the run out at the end of an album the arm just lifts and powers off. But you may be onto something. I still have the owners man. and have looked at the service man. at vinyl engine and haven't found anything that could be a mute circuit, but the English is pretty limited in the service man. I'll keep looking but it is starting to look like I may have two bad carts, or stylus.

apphd

DSkip I might consider that if I had a cat, just not yet It doesn't look like this should be so difficult, unless it is something involved like Stan has suggested. Thanks again all.

apphd

Hi Ken thanks for checking out that schematic. I still don't know what is wrong. But from the cart leads to the RCA plugs I do have good continuity on all four. At this point I have to go with the unlikely fact that I do have two carts that went bad from long term storage/no use. At least after trying your test I am not so hesitant to spend the money on a new cart. Will let you all know what the outcome is.

Thanks again to all.

[Deleted User]

Thanks for letting me know. Most of the time phono cartridges are so basic that not much can happen outside of bending or breaking a cantilever. But, at least you know if a signal were produced by the cartridge it would be available at the end of the RCA connector.

skrol

I have an Ortofon cartridge similar to your OM20, it might actually be an OM20, that I use occasionally. It is 20 years old and works great.

Since you have continuity from the cartridge leads to the RCAs, I am starting to suspect that the issue may be with your phono pre-amp (ART USB phono plus). Perhaps settings? What is the ART USB connected to? How are you powering the ART USB? I ask as there is an FAQ on their site regarding no output that is linked to a DC power supply vs AC.

It looks like a neat device.

apphd

Stan I have the phono pre-amp going to my line level inputs on a Denon X3100W. I borrowed a co-workers TT and hooked it up to the ART and all was good. That was my biggest concern to verify that so I could return it if that was the problem. All indications are that not one but two carts failed for some reason. I still find it hard to believe, which my denial maybe making me over think this. My only decision now is buy the cart I want, or go real low budget to finally convince my self that the two carts failed, then upgrade. But it is basically confirmed from checking continuity from the cart leads to the end of the RCAs with the tone arm mid travel and the platter spinning at speed. I will need to check the FAQ for the ART as my tests so far has been powering it through the USB connection. But I do plan on getting a wall wart for it so I need to check that out. None of what I have read so far has indicated any concerns with that. I think I will mark this as answered, but will revisit it with my impressions on the ART. It has a lot of features that make it a pretty versatile little box at a modest price. Maybe not audiophile but hopefully something that blends well with the rest of my gear, and allows me to get some decent flacs of my record collection to my HTPC.

apphd

Just wanted to update this. I resolved this by replacing the interconnects. Not sure why. I installed a new cart and got the same results. So as a last ditch effort at doing it myself or facing a decision of pro repair vs a new TT, I replaced the TT cabling. Granted it was with a cheap DVM but I had continuity from each pin that connects to the cart through the tone arm and all the way to the corresponding RCA ends. There was some low resistance, IIRC < 1 ohm with one channel reading a little higher than the other. I am still stumped, but problem is resolved. Now I need to chase a ground loop. Thanks for the input from all. Maybe this will help someone in the future.