Phonoland

Rob,

I found two sets of unused RCA jacks on the chassis directly under the phono audio jacks. One set worked when AUX mode was selected, but the volume was noticeabley lower than when using the phono jacks. That also led to the unfortunate discovery that one of the two large, round speakers is not producing sound. Now I'll have to learn how to diagnose that problem.

I did the continuity test you suggested at the red/yellow/black phono power connector. The middle wire is yellow. The red and yellow pair show an open circuit with the mode selector set to anything except PHONO. When PHONO is selected, the reading goes to 0.00 ohms. Am I correct in assuming this is the pair I need to short in order to activate the phono circuit in the amplifier? I'm afraid I didn't understand your comment about putting a light bulb in series somewhere.

By the way, the system is solid state.

I took some good photos and saved them at Shutterfly, but I can't figure out how to imbed them here.

The fact that one channel is dead/low is not surprising, this was the same problem (among others) with mine. I have the ability to rebuild and test electronic assemblies so it was just part of the fun. You can check the speaker connections and use the low voltage AC range of your meter to look for signal at the speakers. But it is likely an electronic problem.

The principal problem in mine was old capacitors in the tone amp section, but given it's age, it is likely that full performance will require replacing all or most of the capacitors. This isn't a big deal IF you know how to solder, read the voltage and capacitance ratings on each capacitor and observe basic procedures.

From your pic (i see only one) it looks similar to mine. I have the Sams Photofact schematics and chassis pics for this era. they are for Chassis R204-08-00 thru R204-17-00. If that is your range, these may be helpful. If not, you can still just replace the small electrolytic capacitors, they are common values, or consider having a local tech do it.

As for the wiring of the AUX vs phono inputs, this is normal in these sets. Magnavox used a low output ceramic pickup cart. The reason is that tracking ability increases as the needle cantilever is allowed to be more flexible. This however means that it is making the grooves do less work in generating electricity -so lower output. Typically that cart was lower than the normal output of a tape deck and the internal radio. So to make the sources balance, more gain is allotted to the phono input. There are simple changes that can give extra level (gain) to the AUX input but you run the risk of distortion on loud records. See if the what you added to the AUX roughly balances the radio in level. If so, leave it as-is.

My reference to a light bulb in series with the power cord is for it to act as a sort of cushion or current limiter. As I said, if you jump the wrong two wires coming from the receiver to the phono it will place a dead short across the power line. Putting a bulb inseries with -one wire- of the plug will prevent any chance of damaging the set's switches or wiring. If things are wired incorrectly, the bulb will light fully. Correctly wired it will be dim if at all.

Do a google image search for "light bulb current limiter" -very simple circuit.

Rob/NYC

The yellow wire makes the amp shut off when the changer turns off.