Tuesday, December 31, 2013

Brother, What a Repair

One of the aspects of garage saling I enjoy is the opportunity to bring new use or life back to castoff objects.  That may mean refinishing abused furniture or a little tinkering on mechanical or electrical items to get them back to 100% (or close) operation.

The Brother stereo I bought last year fell into that category.  

While it operated correctly most of the time, it had a few glitches (a hanging tone arm, sticky 8-track rollers, sound cutting in and out, etc.).  I finally found some time to tinker with it this past weekend.  I thought I'd share some of the things I did to correct the issues.  Let me state right off, I'm not an electrician, but I've found that a little research and general understanding goes a long way in these matters.  It doesn't take much expertise, just a little knowledge and the right tools.

First, the issues I was having:

  1. When loading a record with the auto switch, the tone arm would sometimes get stuck in its cradle by the locking mechanism.
  2. The 8-track tape was eating my 8-track tapes.
  3. More of an aggravation than issue, the tuner indicator on the analog dial was out of sync with the tuner.  For example, to listen to 103, I had to tune to 106.
  4. Finally, the most irritating problem was the speaker cutting in and out on one channel while playing records.
  5. When playing 33 1/3 records, the turntable was turning 39 rpm resulting in everyone sounding like chipmunks.
I did a little web research and found an electrical contact cleaning spray that seemed to be recommended by most people restoring vintage electronics, Deoxit D5 .  It's not cheap; I bought a can on eBay for $13 including shipping.

But before I get started, let me do my best Mr. Obvious impersonation: Attention!  Electronics can shock you.  They can even kill you.  Be aware of the risks.

Okay, with that out of the way, step 1: unplug the stereo.  You don't want any electricity passing through the stereo (or you) when you start spraying Deoxit all over the circuit boards and switches. After unplugging, I like to turn on the power switch.  That way any capacitors with stored voltage should be dispersed.  You might even hear a short click/pop or a flash of the power light.

Let's start with the last issue first because it's a fairly easy fix.  BSR turntables use a small rubber wheel that ride against a stepped motor shaft.  Over time, the rubber on the wheels wears off and clings to the motor shaft and the shaft ends up fatter than it should be resulting in the faster speed.  The first step in resolving this is to remove the platter.  The platter is held on the shaft by a small c-clip.  

This can be removed by applying a little pressure on both ends of the clip and pushing it off of the shaft.  I used my fingers, but you could use a couple screw drivers or needle-nosed pliers.  Watch out because that clip can go flying and easily get lost.

One the platter is removed, you should see easily find the rubber wheel and stepped motor shaft in the front left corner.

When the start switch is engaged, the rubber wheels makes contact with the motor shaft.

Changing the record speed to 44 rpm causes the rubber wheel to drop and make contact a lower, fatter part of the shaft resulting in higher rpm.

My record player also has 78 rpm, so it drops to an even lower and even fatter portion of the shaft.

If you look closely at the motor shaft in the pictures above, you can see a little of that rubber residue left over.  I took these pictures after I had begun cleaning it off.  To clean, I applied some Deoxit and cleaned with a cloth.  Some of the more stubborn portions, I ended up just scraping with my finger nail.  Wipe off any excess Deoxit and replace the platter and c-clip.  The c-clip fits in a groove on the record spindle.  Lay the c-clip level on the platter, start the ends in the groove and push it until it snaps back on.  My rpm speed issue was fixed.

Now let's move on (or backward) to issue #4.  By playing around with the various knobs and switches, I narrowed the problem down to either the balance knob or the phono selector switch.  I could sometimes replicate the cut in/out when tapping on these.  This is generally an indication of a dirty switch or potentiometer (those variable switches such as "volume" whose adjustments allow more or less current to flow resulting in, for example, softer or louder music.)

Next step is to figure out how the stereo dissassembles.  This will vary from model to model.  On mine, it was pretty obvious.  There were visible screws in the bottom of the receiver.  Sometimes the screws can be hidden by footpads.  Peeling those off should reveal a recessed hole with the screw inside. This stereo has the turntable incorporated into it, so after removing the dust cover, I ensured the tone arm was locked in place and gently turned it upside down and rested it on the floor making sure nothing would break from the weight.  If your stereo also has a built-in turntable, be careful when turning over as it will come out of the cabinet slightly.  If your turntable is like mine, it rests loosely on 4 springs that allow for cabinet vibration without causing the record to skip.  Also, turning the receiver over, you want to ensure you don't lose any parts that might fall out or worst of all, not know where they came from or where they go.

After removing the screws you believe are holding the bottom on, gently pry at the bottom and see if it gives.  Sometimes you miss a screw.  If it doesn't give somewhat easily, don't pull at it as you may snap off a mounting post.

The next step is to free the electronics from the housing completely.  I started with the turntable. If you ever wondered why you can pull up on a built-in turntable but it won't come out completely, it's because of these:

After removing the clip frees the turntable from the housing, but before proceeding, you need to disconnect any electrical connections tying it to the amplifier.  On mine, it was simply the phono jacks:

 and power wire harness:

Time to stop again and mention something.  Take pictures.  Take lots of pictures.  Take lots of clear pictures from many angles.  You will never remember how things came apart or what wire goes where without them.  They are invaluable.

I removed these connections at the turntable and both came off fairly easily, but pull at the connector, not on the wires when disengaging.

After removing the turntable, I focused on the receiver.  But wait!  Before proceeding, first identify any knobs on the front of the receiver that will inhibit the removal of it from the case.  I had to remove the Power/Volume, Balance, Tone and Tuning knobs.  These should simply pull off (be gentle, they're probably made of plastic).  The 8-track channel knobs didn't have to be removed as they were narrower than the case opening, but as I was going to be spraying contact cleaner on them so I removed them anyway.  

Now, back to the receiver itself.  It was mounted to the case with 4 screws.  Two were obvious, two were not.  I had look down into the case through a tangle of wires to spot them.  A small, but powerful LED flashlight will help here, especially if your eye strength is fading like mine.  I had to pivot the receiver to navigate the transformer (that big gold box screwed onto the outside left of the receiver in the first picture) around the case, then feed the wiring harnesses and speaker connection plate through the case.  

I probably could have done what I needed to do without removing the components from the case, but I like to be thorough and get to the circuitry from every angle, plus, I just like to know how things are assembled.  I enjoy doing this, and that's an important factor when repairing things.  If you don't like doing it, you're not going to do a good job.

Once the components were out, I could see the manufacturer's labels and confirmed what I suspected: Brother outsourced the receiver and the turntable and simply slapped their brand on it.  BSR of England manufactured the turntable, which is common to a lot of built-in turntable models of the '70's.  

The receiver was manufactured by a company called "Capetronic" out of Taiwan.  There's still a company in existence by that name, but I'm not sure if they are related. 


The model of receiver is a Capetronic 1R113AC.  I put that there simply to be the only Google result of that string in all of the webverse.  Unfortunately, I couldn't find any manufacture dates, so the exact year for this is still unknown.  I still place it in the first half of the 70's.

Now that the components were freed, I could begin my cleaning.  First, I started with a simple vacuuming of the electronics and case to remove hair, dust and other nasties it had gathered in the past 40 years.  

I then used a pressurized air can to blow out all over.  Now it's ready for cleaning the electronic connections.  Reading the directions on the can, you simply give 1 short burst onto each contact.  If you're cleaning a switch or knob, operate it (ie: turn on/off, turn up and down, etc.) to help free up any dirt.  Wait a few seconds and repeat with another short burst.  Wipe off any excess and allow to dry.  

The can states 2 minute dry time, but I was much more conservative giving it at least 10 minutes.  I was pretty liberal in spraying, hitting every circuit connection in addition to the switches and potentiometers.  I also repeated the application on switches just for good measure.  The spray leaves an oily (presumably non-conductive) coating which is to protect it from future rust.

Next, I addressed issue 3, the misleading tuner indicator.  

This is a fairly simple fix.  These analog dial indicators are simply a plastic piece clipped onto a string that's wound around the internal tuner. 


I tuned to the station I wanted to calibrate with, then taking grip of the string (gently again) with a needle-nosed pliers, I pulled the plastic dial, sliding it along the string until it aligned with the correct station on the dial window.

Cleaning the 8-track rollers and head requires q-tips and isopropyl alcohol.  Simply wet the qtip and wipe across the head and the rollers (little plastic or rubber wheels within the tape mechanism.  If you're not sure what to clean, insert an 8-track cartridge and see where the tape touches.

Before going through the trouble of reassembling, make sure the receiver still works.  The turntable wiring harnesses don't need to be reattached for this if you just want to test with the radio or 8-track.  While the electronics are exposed, be careful what you touch.  Assured that everything still funtions properly, reassemble the components and cabinet in the reverse order referring to the many pictures you took up front.  Make sure all seams on the case fit together properly and don't overtighten any screws.

One problem I ran into was a couple holes in the plastic housing wouldn't line up with the receiver screw holes.  

I've found an ice pick works great for this.  Insert the ice pick into one of the screw holes and leverage the screw hole into place.

Insert a screw into one of the holes, and the others should stay aligned.

Once reassembled, I tested everything out: tuner lined up properly, no cut in/out on the speaker, 8-track played smoothly... Wait, what about issue #1 you ask?  Oh yeah, the sticking tone arm.  Well, I have to admit, I lucked out there.  Apparently, through my liberal spraying, I must have hit something that freed it up.  It consistently works now.

I hope this helps someone else out there with their own vintage electronics, and if it does help, drop me a comment about your successes.

Being this is my last post of 2013, Happy New Year's to all and here's to a hopefully bountiful 2014 of garage and estate sale finds!

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