Home stereo question (output problem)
 

I've got my (family's) old tuner and turntable set up in my dining room so I can listen to my LPs. It's a Yamaha R-700 tuner and Technics SL-D20 turntable (early '80s vintage) hooked up to some spare mini-stereo speakers that I had sitting around. It worked fine until suddenly it didn't. Now when I cue up a record, I effectively get no sound. Output is going to the speakers, and if you listen close you can hear the music playing very softly. On top of that is a loudish hum. When I switch the input or output on the tuner, I get a loud snap/pop when I switch sources. I really have no idea what is going on, and I'm far less comfortable diagnosing electronics that I am mechanical stuff, so I figured I'd ask here. Nothing happened gradually - it was fine one day, not fine the next (as best I can remember.) Is this as simple as bad RCA cables? It's the only thing I can think of. I don't have any spares I can swap in to do an A-vs-B and I'm reluctant to buy a set just for that purpose. I doubt anything is wrong with the tuner. Speakers? (Is this something that can happen to speakers if you over-power them, or do you just blow the cones out?) I just remembered I've got another set i can swap in, so I guess I'll try that when I have time.

No expert, but I always start with elimination. First swap the speaker connections right/left or to the "B" connection on the amp and establish that both speakers and cables are working, or try them with another amp Then connect the speakers to another source output on the amp and see if that works, if the switching pop is still going on. If its the amp, I'd open it and hit all the pots and switches with a liberal does of contact cleaner. This may take 24 hours to yield result. If no fix, amp to the repair shop. If its not the amp, and its the turntable....cant help you.

Start with the basics. Turn on FM and try playing it through headphones. Anything?

Lots can actually go wrong here. Can you change sources like a cd player? Is the pre in your receiver still working? Phono cartridge still intact, rca's and turntable ground still hooked up properly?

I agree with Lee,

switch to the tuner in the receiver to eliminate everything associated with the turntable.

Listen through headphones to make sure the regular part of the receiver is working.

If it is, undo the speaker connections on both ends and reconnect.

If nothing, try one speaker at a time.

If nothing, switch to the alternate outputs, if there are some (A and B)

Make sure that if there is a speaker button (A and B or something) that it hasn't mistakenly been turned off.



good luck!

FYI:

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Turntable need to be grounded?

They def should be grounded. Both of my turntables and my pre-amp have a provision for a grounding wire.

Without a ground you can get all sort of noise/distortion introduced into the system.

maybe power to the internal pre-amp died

or a mute button got pushed
other control switched wrong
or headphones are plugged in

blown speakers go one at a time
as do one side of the main amp

More possibilities than I expected! I will let this guide me tonight if I get home early enough. I can't switch outputs on the tuner, as there is one set of outputs specifically for the phono. I wanted to try headphones but I couldn't find a jack adapter.

Otter,

You may be mistaking "outputs" and "inputs."

If the unit is like the one in Lee's video, you can see on the lower left there are buttons for "speaker A and B."

The "Rec Out" knob means nothing in your situation. If you can turn the "input" knob to "Tuner" you should expect to hear radio or at least some static through the speakers.

If you turn the knob to FM, for example, and hear noise out of the speakers, then the problem is in the turntable hookup.

If you turn the knob to FM and hear nothing through the speakers, but hear noise or radio through some headphones, then the problem is in the speaker connection (or the power amp part of the receiver.)

If you turn the knob to FM and hear nothing through the speakers AND nothing through the headphones, then it's in the preamp section of the receiver and you should (probably) start looking for a replacement.

SmileWavy

Ever get it figured out?