Magnavox Astro Sonic Console

Hello everyone,
I'm new to this site and just joined last month. A friend of ours was moving and gave us a Magnavox Astro Sonic Console, model number 1ST693. This Maggie is awesome, and we love it, we are in the process of cleaning her up and restoring her to her formal glory. She a big girl, about 6ft long, has 15in speakers, and has a remote for a power tuner, which trys to work but needs to be cleaned and re-strung. When we got her home I opened the back and blew all of the years of dust out of her and cleaned her up a bite. After that we pluged her in and she worked great and sounded great. I replaced and re-soldered the wires on the needle and it worked fine after that. The problem we have now is that the right speaker doesnt work anymore and when you turn the balance know to the speaker, we get nothing. Only the left bank speaker is working. I've been reading a lot on this site about Maggie re-caps and was wanting to see what everyone thinks on here about what could be wrong.
I could also use some help as to were to start.
Thanks
Jamie

Check all your wire connections before tearing into the thing. I removed an amp/receiver from an old Astro-Sonic. Even built its own case to give it that "component look" to use with some external components. One channel went dead, and I thought..."I'm not in the mood do do any cap jobs right now." One of my wires was bad, so problem solved. I do plan on recapping the thing anyway, but it works wonderfully and is at the bottom of my list.

I do have a couple of consoles acting alittle strange, but I'll check all the wiring first before ripping out tuners and amps. Remember, these Astro-Sonics were the crossover in the early 60's to solid-state, so we're looking at some old caps that will eventually fail.

Some of the early consoles had the balance control right on the chassis (inside the cabinet), while some, like the Astro-Sonic 100's, had a separate tuner with the balance control on the face plate

Check all you wires first before going on to major surgery. Reverse the wires to see if the sound transfers to the other channel. See if your radio and any external sources are playing through both channels. Do a process of elimination. I got one Maggie here with the same issue, and hoping it just may be a bad wire/connection. --BB

Bobby Basham
Tucson, Arizona

Thanks for the reply Bobby.
I tried switching the channels already, and the right bank works fine when I switch them. So I think this old gal needs a re-cap done. I just dont know where to start or what to look for. Do you know any sites or books that would help me out? Oh forgot to mention that this is a 1964 model.

I've found buying the SAMS photofacts online to be invaluable as to replacing caps, etc. You just have to know the chassis numbers (like 79-05-10 or whatever, usually a sticker or stamp on the chassis, not the unit model number). All you need are the parts, your soldering iron and a voltmeter and you're good to go...with the photos, you don't even have to be able to read a schematic. Also alignment instructions, if necessary, using all the little pots, restringing diagram, etc. Well worth the price for the pdf of it.

As for general troubleshooting or electronics guides, I'm sure there are books if you don't find what you need online. Testing the continuity of the wiring first is a great suggestion!

As far as resources go, there's alot of info out there.

I picked up a little book at Radio Shack regarding using your meter. That came in handy when you want to check your semiconductors, especially Transistors. Caps are clearly marked with their values and voltages, and resistors have their color code bandings (get a color chart).

Someone mentioned that the NTE/ECG semiconductor cross reference guide is available on line now. The latest I have is edition #11 (March, 2003) in hardcopy. I think edition #14 is available online. A part with a weird number on it tell will cross to an appropriate NTE/ECG substitute. It also has diagrams of the components with the specs listed below. Howard W. Sams also put out a similar publication.

There was another book (or software) which I can't find, but would take a part number and cross reference it to a GE, Motorola, Radio Shack etc., and an NTE/ECG replacement.

Back in 1999, I picked up a 2nd edition of "Troubleshooting & Repairing Consumer Electronics Without A Schematic. It includes alot of scenarios of problems and how they were solved. If you're really into it, it was interesting reading.

Not knowing your unit, your problem could just be connection issues or a cap job in order. Cap jobs (electrolytic) eliminate a lot of other issues. Just my two cents. --BB


Bobby Basham
Tucson, Arizona

Thanks to everyone for the informative replies, this site is great. I'm currently reading on line about how to recap old radios. I looked for the chassis number on my Maggie and cant find one. I'm going to turn it on its side this weekend so the I can look on the bottom for the number. I'll also try to fine the books that are suggested, thanks Booby. I'll let everyone know how everything is coming a long once I get started.

Pghcoyote brought up a good point about the stickers. I don't think I've ever come accross a Maggie that didn't have them. They're less than an inch square, and could say something like

R214-04 AA
Chassis
01/68 (January, 1968)

At least that's what mine says. Sometimes the chassis number is stenciled in large lettering on the side that has your speaker/antenna/pilot connections, and a separate little date sticker on top of the chassis, maybe near the tuning section. Your console sounds like it could be a mid-60's.

Yes, please keep us posted...progress gives us a warm, fuzzy feeling and motivation to move on. --BB


Bobby Basham
Tucson, Arizona

I had a similar problem on a unit I just picked up with the left speakers not making any sound.

Fiddling with the bass switch brought the left side alive.


Joe

Hey Joe,

You got some dirty contacts on your controls. I had to rock my bass control back and forth to temporarily bring both channels in and reduce the scratching sound when adjusting the sound. It also happens with the selector switch. I'm a great procrastinator (my workroom not ready yet), but it's time to remove the tuner and clean those pots with some Deoxit, or what other brands are out there. By all means, DON'T USE WD-40...save that for squeaky doors and hinges. --BB


Bobby Basham
Tucson, Arizona

I had a similar problem with my '60, as described on this thread:

viewtopic.php?f=19&t=2709

Today, that phono sounds great in both channels. The moral of my story is that the resistors should not be ignored; while you're in there changing capacitors out, check the value of these resistors and if you find any dead ones replace them.

Yep, I agree about the resistors...

I have a 1968 Zenith portable that had channels off-balanced. Did a cap job, even replaced those output transistors, but it was one single resistor that was the culprit. I learned that resistors do fail just like caps. The balance is centered now and I keep it in my 2nd bedroom/office and play it daily while I'm getting ready for work at 5:00am...YIKES. That's too early for man nor beast...LOL --BB


Bobby Basham
Tucson, Arizona