GE Model TA-600B 8-Track Tape Deck Repair

The GE TA-600B is a Solid State (Transistorized) 8-Track Tape Deck. Through my research I have discovered that it was first offered in 1972, and equipped with two microphones for stereo recording, with a low suggested price tag of $109.95! The TA-600B offered the same basic controls as with other similar 8-Track Tape Decks offered at the time including Fast Forward, Manual and Automatic Channel change,  Record mode with input volume level controls and VU Meters for monitoring. The TA-600B could only record and playback two recording tracks at a time.

I acquired my GE TA-600B from a relative's garage sale several years ago. It came "Untested" with many boxes of pre-recorded and dubbed Polka music. It is a good thing that I had some Rock and Funk 8-tracks tapes by Queen and Casey and the Sunshine Band as Slovenien Polkas by Frankie Yankovic is really not my fare.

Upon connecting the GE TA-600B's stereo output to an amplifier, powering it on, and inserting a 8-track tape, I knew immediately the tape deck had a problem as a strange "motorboat" noise was coming out the both speakers instead of the sweet sound of  "Shake Your Booty" by KC and the Sunshine Band.

Time to open up the GE TA-600B to discover what is amiss!

Radio Restoration Books on Amazon

​I consult these books often during radio restoration. I grew up in the transistor and rectifier era and these books taught me a lot about vacuum tube and selium rectifier technology.

A rubber band is not a drive belt!

One of the first issues I noticed upon removing the cabinet from the TA-800A is that a previous owner replaced a broken drive belt with a rubber band. Please do not replace a drive belt with a rubber band. A rubber band has different elasticity properties than the drive belt and causes strain on the driver motor with may cause it to fail. A new drive belt for the TA-600B and many other models can be sourced at www.turntableneedles.com 
Most drive belts from this site are a little under $10 and they include free shipping. Below is a link to the site. 

www.turntableneedles.com​

For some reason vintage drive belts turn into this tar-like black goo as they age past their prime. This "goo" gets all over the pulleys, tape drive head, and other electro-mechical parts. I use denatured alcohol to throughly clean the drive belt "goo" from all internal workings then let it dry before replacing the drive belt. Below I am cleaning the drive pulley that drives the capstan.

Next I cleaned the pulley on the drive motor. 

Finally, pictured below, is the new drive belt installed.

Electrolytic Capacitor Replacement

As electrolytic capacitors age, their electrolyte dries up causing their electrical capacity to drop and leakage current to increase. It is definitely a good idea to replace electrolytic capacitors that are over 40 years old!

If you follow my blog, you know that I am a big advocate on replacing vintage electrolytic capacitors even if they test "good". In fact, my first troubleshooting step in any vintage electronic equipment restore is to replace ALL of the vintage electrolytic capacitors.

Electrolytic capacitors should be replaced with one of the same or slightly greater capacitance and working voltage rating. For example, in most cases, it is perfectly acceptable to replace a vintage 3uF 12Volt electrolytic capacitor with a  new 3.3uF 50Volt one. You will find non-standard electrolytic capacitors values in electronic equipment that were built before the electronic industry instituted standardized values.

Click on the "Capacitor Replacement Guide" button below to see a great web page regarding capacitor replacement in vintage equipment.

Capacitor Replacement Guide

The first step was to replace the electrolytic capacitors, circled below, on the small printed circuit board. I believe this is a board that regulates the speed of the drive motors. I am not sure as I was unable to obtain a schematic for the TA-600B.

A lot of times I troubleshoot sans schematic if I can't source one for free. After all, it does not make sense to purchase a schematic from SAMS Photofact for $20 when you purchased a electronic device from a garage sale for $1.

I typically mark replaced electrolytic capacitors on the top with a black permanent marker because sometimes its difficult to discern the original from the new one.

The next step was to replace the three electrolytic capacitors, circled in red below, on the Power Supply board.

As you can see below, the replacement electrolytic capacitors are significantly smaller than the originals.

The left and right side of the main printed circuit board is a mirror of each other. The left side is the audio amplifier circuit for one stereo channel and the right side is the audio amplifier for the the other stereo channel. The two long metal cylindrical things toward the center of the printed circuit board are switches used to change the mode of the TA-500B from playback to record.

You can see that there are also mirrored patterns of electrolytic capacitors on the printed circuit board as well. 

It took several evenings to replace all of the electrolytic capacitors in the TA-600B. I have about an hour each evening to truly devote to my hobby. Below is a picture of all of the discarded electrolytic capacitors from the TA-600B.

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Bench Testing

With all the electrolytic capacitors replaced in the TA-600B, the moment had arrived to do some initial testing before performing any more troubleshooting. As mentioned, I have solved many issues with vintage equipment just by replacing all of the electrolytic capacitors. 

I moved the chassis to a table close to my audio equipment rack then plugged the TA-600B's left and right channel stereo output RCA cables into the auxiliary inputs ​of my vintage Kenwood SX-580 AM/FM Stereo Receiver. I powered on both SX-580 and TA-600B then inserted an 8-track tape and heard........nothing! How disappointing, at least I got a distinct "motorboat" sound when I started this project. Duh, then I remembered that I needed to switch the selector on the SX-580 to Aux. Suddenly I heard the sweat sounds of KC and the Sunshine Band 8-Track coming out of both stereo channels of the Kenwood!

Simply  replacing the electrolytic capacitors in the TA-600B had resolved all of its problems. 

Oh, that's the way, uh-huh, uh-huh,  I like it, uh-huh, uh-huh :-)

Detailing

One of the last things I do with vintage electronic equipment is detail the external enclosure.  Detailing involves meticulously cleaning the external cabinet then applying the proper protectant depending on if it is wood, metal, plastic, Bakelite, leather, or vinyl. 

It was taught to me many years ago in vocational electronics that the last step in servicing a customers television, stereo, or other consumer electronics is to detail the cabinet.  Most customers are more impressed on what you do on the outside of the cabinet then what you do on the inside!

I used Lemon Pledge to restore the shine in the wood veneer of the TA-600B's cabinet.

Q-tips work great for cleaning small crevices like switch slots on the front of the cabinet. I used Armor All automotive protectant to restore the shine in the black plastic faceplate of the TA-600B. In fact, many of my tools of trade in electronic detailing come from my automotive cleaning supplies. 

Below is a picture of my newly repaired TA-600B gracing my audio rack.

Finally the TA-600B in action!

Playing a little KC and the Sunshine Band!