atomic_fungus (atomic_fungus) wrote,

#6433: Very good, but in order to find out, I'll have to clear it off and remove the chassis.

I should have snapped pics. Enough time for that later. Anyway:

...had a gander at the guts of the console stereo. As mentioned in a prior post, my theory is that at least one diode blew in the power supply, and all I should have to do to restore the thing to full function is to replace the blown diode(s) and all the electrolytic capacitors, and it should work beautifully.

"Should" being the operant word. There may be something else wrong with it; but in order to find out I need access to the appropriate circuits.

The thing is a bunch of boards, each subassembly constructed with 99.9% discrete components, which--believe me!--will make this easier rather than harder. With a modern component stereo, which is 90% ICs with a handful of SMD components for good measure, well--you don't use a soldering iron on one of those; you use a solder reflow oven. If, that is, you cannot simply replace the entire assembly.

I have a soldering iron; I don't have that other thing.

Anyway, the circuitry should be fairly simple to suss out, and that's good, because there is no circuit diagram provided. If I can find a model number I might be able to look one up on-line, but I wouldn't bet on it. Regardless, I know enough about amplifiers etc that I should be able to figure out what's not working, and replace it.

So: moved it away from the wall and looked at it. Power socket here, where the circuit breaker is also located. Wires go up to...oh. Well, it looks as if the power supply board is on the side that faces front, and the only way to get at it is to remove the entire chassis from the thing. And the chassis goes out through the top of the stereo, which is covered in boxes. *sigh*

Digging through it, though, I figured out a couple of little things. The turntable and 8-track are AC-powered--not a surprise for a stereo of this vintage--and they did build the chassis so you could take it out of the box without a lot of unsoldering.


Three-way speakers; the woofer is 15 inches. Suspension rotted on the left-hand one, and it's an easy bet that the right hand one isn't much better off. I made that determination in 1991.

But it's relatively easy to find places that re-suspend and re-cone speakers. Or I could just buy new ones. In 1991, I could have gone to Radio Shack and paid $30 apiece for reasonable quality 15" woofers, but Radio Shack is gone. Even if they weren't, inflation--so they're closer to $90 now, at least from the one place I really looked at.

Those speakers from Radio Shack were actually pretty good--I put them in the Blue Bomb for its stereo; as long as you didn't abuse them, they worked and sounded great. And they didn't cost an arm and a leg, either; I think I paid $30 for the pair I put in the car, and even with a 20w/channel booster, there was never any distortion or clipping from them. The 15" woofers they sold for $30 apiece would have been fine for this system.


...anyway, that's a way off. First thing is to clean off the top of the thing and get the chassis out; once it is, I can have a gander at the power supply board and see what needs attention. I can count up electrolytics and get a BOM put together for the repair, too.

After dinner.

* * *

Looking over some old Radio Shack catalogs on-line....

The speakers I put in the Blue Bomb were, in fact, $12 apiece at the time. 30w speakers, $11.95, plus tax. So, not even $30 for the pair, and sounded fine.

The 15" woofer was $60 in 1991; it was $40 in 1986. Looking at that now I remember that's what drove me just to go buy new speakers.

You see, for Christmas in 1990 I'd gotten a new stereo--just the amp, because it was a bit spendy. Anyway, I reasoned, I work and go to school so I should be able to get speakers, right? But in the meantime, I pulled the back off the old console and connected its speakers to my amp, and it worked well--until the left side started distorting, and I pulled it apart to find that the foam suspension had perished. I never even turned it up that loud; just bear in mind that by then the stereo had sat unused in that basement for most of a decade...and the basement had flooded a couple of times, so conditions down there had been "damp".

Anyway, the woofer died, and I assessed my options. 1) Buy new woofers from Radio Shack, $60 apiece, or 2) Go to Sears and buy a new set of speakers for about $75 apiece. That was an easy choice.

I wanted this lovely set of Fisher 3-way speakers which had massive woofers and looked really nice--and a friend's mother had a set and they sounded great--but Sears would not honor my Visa card. At the time they only took Discover and the Sears charge card. I had neither and couldn't get approved for Discover, so I went to Ward's, where I bought a set of speakers that were not my first choice, but at least they cost less because of Dad's employee discount.

I somehow managed to cram them into my 1977 Impala, got them home, hooked them up, and was happy. I still have those speakers and they still work fine.

* * *

That '77 Impala--it was a 2-door, blue, and it had some miles on it. My cousin's husband had bought it from my uncle, his father-in-law, and then sold it to me. I drove it on that commute to school and work for most of a year.

It had GM's fantastic Metric 200 transmission, which was--charitably--a piece of shit. It could not handle the torque of the car's 4.3 liter V-8, 1970s Emissions Version, which had the approximate power and torque of a wound-up rubber band. A few months after I bought it, $400 went to repair the transmission. Whee!


  • Post a new comment


    default userpic

    Your reply will be screened

    Your IP address will be recorded 

    When you submit the form an invisible reCAPTCHA check will be performed.
    You must follow the Privacy Policy and Google Terms of use.