Author Topic: 1962 Magnavox Astrosonic Stereo Theatre  (Read 3674 times)

PanAm

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Re: 1962 Magnavox Astrosonic Stereo Theatre
« Reply #30 on: August 15, 2017, 12:16:01 PM »
And here's the last ones:

electra225

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Re: 1962 Magnavox Astrosonic Stereo Theatre
« Reply #31 on: August 15, 2017, 09:01:48 PM »
External speaker wires.  Unless my eyes are not looking correctly, that terminal strip on the back is not wired correctly.  There should not be two black wires.  All the commons are supposed to be connected together.  That not being wired right might just kill one set of speakers.  Refer to the sticker pasted in the cabinet that you posted a picture of.  Somebody has had this apart before, witness the pieces of tape with numbers on it.  Before you go any farther, I would seriously suggest you make sure the speakers are wired right.  The console should play without the back on and without the external speaker terminal wired up.  See if your dead speaker(s) work with the back off like it is. Could you post a head-on picture of that external speaker terminal?  Not at an angle like it is now.  I'd like to see how the second black wire is connected.

Edit.  The pictures you just posted show the speaker in the top picture missing a wire.  It needs that wire re-connected.
I don't need Google.  My wife says she knows everything.

PanAm

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Re: 1962 Magnavox Astrosonic Stereo Theatre
« Reply #32 on: August 16, 2017, 09:28:48 AM »
The speaker tab that is missing a wire isn't supposed to have a wire connected to it if I am reading the schematic correctly. It is exactly like that on the left side too and that is the side that is working correctly.

PanAm

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Re: 1962 Magnavox Astrosonic Stereo Theatre
« Reply #33 on: August 16, 2017, 09:31:14 AM »
The last one:

electra225

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Re: 1962 Magnavox Astrosonic Stereo Theatre
« Reply #34 on: August 16, 2017, 09:50:21 AM »
The diagram showing speaker connections is drawn a bit differently than I have seen.  There is a "2-1-C" terminal, shown below the external speaker terminal on the back.  I don't see that terminal in your pictures.  It shows that double black wire.  Perhaps that is where the two loose black wires connect.  I don't see on the diagram any indication that any speaker will have an open terminal, but if the channel that works is like that, so be it. 

As an aside, and something I have wondered about, the TV chassis power plug is powered from the tuner chassis.  The TV has its own power supply, rectifier and that, apparently?  And an RCA-style jack with a wire going to the function switch for audio and the function switch providing power to the TV chassis?

You could reverse the speaker connections on the amplifier, shown behind the output transformers, to see if the dead speakers work.  That will tell you if the problem is in the speakers or their wiring or in the electronics.  After you are satisfied that the speakers work and are wired right, you can troubleshoot the electronics with confidence.  Hang in there.  You're doing fine!
I don't need Google.  My wife says she knows everything.

PanAm

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Re: 1962 Magnavox Astrosonic Stereo Theatre
« Reply #35 on: August 16, 2017, 11:16:45 AM »
Thanks for the reassurance electra225. I am so scared I am going to break this thing though. The double black wire comes out of the remote stereo channel 2 port on the back panel but is looped into the remote stereo channel one port and the extension channel one port. My question is, where do the double black wires connect to inside the unit? You are correct about the tv having its power source from the tuner. Only way to turn on the tv is to put the knob on tv.

PanAm

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Re: 1962 Magnavox Astrosonic Stereo Theatre
« Reply #36 on: August 16, 2017, 11:22:45 AM »
Just noticed the woofer on the right side is missing a wire. Is it supposed to connect to one of the double black wires? Also the woofer on the left has blue, green, and two black wires going into it. The schematic makes no mention of a blue wire? Is it possible someone was in the middle of rewiring it and gave up? Also, how do I reverse the speaker input? That would be a great way to narrow down the issues.

PanAm

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Re: 1962 Magnavox Astrosonic Stereo Theatre
« Reply #37 on: August 12, 2018, 07:08:58 PM »
Hey guys,
Iíve been on a hiatus for a while, lifeís got in the way. I pulled out the 6EU7 in the tuner you guys suggested to do. It was wrapped with a metal tube that it easily slipped out of. I looked it over, too prongs were bent about so I straightened them. I put it back in, turned on the stereo, let it warm up a bit. As soon as the needle touched the record, the speakers made a horrible screeching sound, like a high pitched police siren. I know itís not the changer as I have not messed with it at all because it works like a charm and was working fine two minutes earlier. All evidence points to the tube. I ordered a new one online. Am I correct in my assumption and where should I go from now?
Thanks,
Jack

electra225

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Re: 1962 Magnavox Astrosonic Stereo Theatre
« Reply #38 on: August 12, 2018, 10:57:37 PM »
The sleeve the tube was in was a tube shield.  I needs to be there.  The screeching is probably not caused by that tube or any tube.  More likely an open ground in the cartridge wiring somewhere.  Or anywhere.  Does it screech in another mode of the function switch?  Does it screech in FM?  Or AM?  If not, the problem is in the phonograph somewhere.  If it does, then you need to look elsewhere.  How did the tube pins get bent?
I don't need Google.  My wife says she knows everything.

PanAm

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Re: 1962 Magnavox Astrosonic Stereo Theatre
« Reply #39 on: August 13, 2018, 06:57:59 AM »
I did not check to see if there was screeching in the radio or not. I just shut it off immediately. By cartridge do you mean the needle cartridge? If so, I had zapped myself earlier that evening touching the underside of the tone arm but never gave it any thought as I figured it was always like that. I will attach a picture of the underside of the tone arm.

PanAm

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Re: 1962 Magnavox Astrosonic Stereo Theatre
« Reply #40 on: August 13, 2018, 07:05:51 AM »
Some pics of the underside of the tone arm:

Bill

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Re: 1962 Magnavox Astrosonic Stereo Theatre
« Reply #41 on: August 13, 2018, 07:39:59 AM »
Greg was referring to the cartridge in the tone arm, if defective they will produce a horrible screeching sound.  I am more concerned that you got zapped touching under there.  Zapped like 110 volt zapped? 

Bill

PanAm

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Re: 1962 Magnavox Astrosonic Stereo Theatre
« Reply #42 on: August 13, 2018, 09:28:34 AM »
Zapped like I felt a vibration and I kept my hand on there and it started to sting a bit. Not anything serious, just knew I touched a live wire. I donít know if by picking it up from underneath I messed some of the wiring up, but all I know is it was working like a charm literally five minutes before that. I ordered a new needle a couple days ago. Should I also order a new cartridge too? Or is it just messed up wiring. I hope you can see in the pictures because my untrained eye canít tell.

electra225

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Re: 1962 Magnavox Astrosonic Stereo Theatre
« Reply #43 on: August 13, 2018, 10:57:51 AM »
That looks like a Euphonics cartridge.  I have only owned one.  The compliance was all wonky on it, so I subbed it for an EV 26.  Getting zapped, even gently, is not normal nor is it good.  Something is not right.  Sounds like it is time for some serious troubleshooting.

First thing I'd recommend is to see if the screeching is in all modes of the function switch.  Then take it from there.
I don't need Google.  My wife says she knows everything.

PanAm

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Re: 1962 Magnavox Astrosonic Stereo Theatre
« Reply #44 on: August 16, 2018, 08:19:57 PM »
Alright guys, I replaced the 6EU7 in the tuner. That didnít solve the speaker issue. On a good note, the screeching noise is not in any of the other modes. Now I need to figure how to get and install a new cartridge. Iím considering buying another changer like mine and using it for parts and as a test unit. I still donít understand what the MPX adapter does or if mine even has one. Would that have anything to do with it? Sorry about that barrage of info and questions. At least I can eliminate that tube as a possible suspect.