Fisher MC-3020 Stereo Rebuild

I rescued this early 80s Fisher Model MC-3020 Stereo from our next door neighbor's garbage. Originally, its was his mother's and had been stored in her garage for many years. It came into my neighbor's possession when his mother passed away. The MC-3020 was known as an Integrated Component System, and incorporates a AM/FM Stereo Receiver, Stereo Cassette Player/Recorder, and a BSR made 
3-Speed Turntable.

MC-3020 Problems

Upon initial power up, I found that my garbaged picked MC-3020 had the following problems:

• Sound would only come out of the left speaker in AM/FM and Cassette player mode.
• The Turntable Platter and Tone Arm would not move at all in Manual or Auto modes. 
• The Cassette Player played the cassette at slower than normal speeds. When you pressed the stop button the play button would launch into the air.
• The Cassette Player counter did not move at all in play, fast forward, or rewind modes.

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Disassembly

The first step is to completely disassemble the MC-3020. I started by removing the screws circled in red, these screws hold the chassis in place.

You must remove both the cassette player and turntable assemblies before removing the chassis.  Four screws, circled in the picture below, hold the cassette player to the wooden cabinet.

You must detach this AC Choke from the chassis, using the screws circled in red, before removing the cassette deck assembly.

Carefully lift up the cassette player assembly and then disconnect all wiring to the the chassis. The cassette player assembly is then free and clear of the wooden cabinet and can be set aside for later servicing. 

The chassis must be slid as far forward until an obstruction is felt. This will allow you to reach inside from the front to free the turntable from the wooden cabinet.

The turntable assembly is held in place on the underside by two clips, positioned diagonally from each other. You must reach in from the front of the wooden cabinet to remove them.

Disconnect the right and left Tone Arm audio connections from the back of the wooden cabinet, noting their color and position.

The turnable assembly can be removed, once the remaining electrical connection has been disconnected. At this point, the chassis can be remove from the wooden cabinet by pulling it forward.

Once removed from the wooden cabinet, I recommend propping up the turnable assembly on several 2x4 wood blocks, so that the mechanical undercarriage is not bearing the weight.

Chassis Switch and Control Cleaning

Upon initial testing, I discovered that the right audio output was not working on my MC-3020, I suspected the culprit was a dirty switch or mechanical control. As such, I decided to spray contact cleaner​ inside every mechanical control in the chassis then put them through the motion several times to clean up the contacts and the resistive elements the contacts may touch.

First I sprayed one Function switch deck.......

and the other Function switch deck.

Both decks of the Volume control.

And inside the remaining Balance, Treble, Bass, and the Recording Level controls. In addition, I sprayed contact cleaner inside the Tape Monitor, Loudness, Mode and Power buttons. Here is a picture of me spraying contact cleaner inside the Tape Monitor button. Don't forget to exercise the control after spraying contact cleaner into it!

Tuner Dial Lubrication

Like many stereos of the era, the MC-3020 uses a dial cord and pulleys to connect the Tuning Knob, Tuning Variable Capacitor, and Analog Dial Frequency Indicator together. While the chassis is out, it is a good idea to lubricate the shafts of each dial cord pulley . I use Labelle 107 Oil as it is safe on plastics and I have it around for my model train hobby. 

Chassis Indicator Light Cleaning

The MC-3020 uses many incandescent bulbs for back lighting and for indicators. As the chassis is apart, it is a good idea to clean them using Windex and a lint free chamois. 

Here is a "before" picture of the Tuner Dial Backlight bulbs, notice their dirty glass envelopes.

Here is a picture of the Tuner Dial Backlight bulbs after cleaning. Notice the difference?

In addition, I recommend cleaning the ​Tuner Dial Backlight enclosure as well.

With the Tuner Dial Backlight enclosure removed, you can access the back of the Tuner Dial Bezel for cleaning.

The Record and Stereo indicators use small light bulbs. I recommend cleaning these as well.

I recommend cleaning the Record and Stereo indicators light bulb enclosures as well using a Q-tip moistened in Windex.

The Recording Level Indicator meters can be removed from the chassis, allowing you to clean their meter faces.

Chassis 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 40 year old electrolytic capacitors like the ones in the MC-3020!

Electrolytic capacitors should be replaced with one of similar capacitance and equal or above Voltage rating. These type of capacitors are also polarized so make sure you observe the polarity of the capacitor to be replaced and install new the same way.

I check each replacement capacitor with my trusty GM328 Multi-Function Tester before installation.

I replaced electrolytic capacitors on one printed circuit board at a time in the chassis. In this case I am replacing the capacitors on the "AIN Power" board. I mark the replacement capacitors with a permanent black marker line on top to indicate they have been replaced as sometimes the original and replacement capacitors look very similar. The light blue one circled in this picture still needs to be replaced.

In many cases, new electrolytic capacitors of same capacitance and working voltage are much smaller that their older counterparts. 

After the electrolytic capacitors on a printed circuit board are replaced, I test the chassis by connecting speakers, antennas for both AM and FM, then connect power and turn it on. You do not need to the connect the cassette deck or turnable assemblies for this step. Just turn the mode switch to AM or FM only. Notice that I did not replace one of the large capacitors on the AIN Power board. I will have to come back to replacing this capacitor as I did not have one with the proper capacitance and working voltage in stock. One of the first things I noticed was that sound was now coming from both speakers now. Looks like applying contact cleaner to the mechanical switches  and controls in an earlier step resolved my right audio output problem.

Turnable Repair

As mentioned, the turntable platter and tone arm would not move at all in Manual or Auto modes when the MC-3020 was powered on. In addition, I could not remove the spindle or turn the platter by hand. My experience with turntables has shown me that the culprit is old grease that has decomposed into a glue like gunk. Your best weapon against grease turned gunk is heat. When applying heat to the spindle make sure you do not melt the rubber mat that covers the platter.

The platter bearing was seized as well. After removing the e-clip. I took the solder tip out of my 40 Watt Weller soldering iron then used the soldering iron to heat up the bearing, and by proxy the grease in it, until I could lift the platter off of its shaft.

After reapplying heat several times, the platter finally came off. This exposed the idler wheel, used to control the platter speed, the left and right tone arm audio connections to the chassis, and the tone arm gear. 

I had to also apply heat to the tone arm gear using a solder gun, in order to thin the old grease, allowing it to be removed from the plinth or base.

Here's a picture of me using a Q-tip to remove the old grease from the platter shaft.

Time to lube things up on the top side of the plinth. After cleaning out the old grease, I applied Labelle 106 PTFE grease to the platter bearing before assembly.  Labelle 106 is safe on plastics and I always have a tube of it due to my model train hobby.

The platter bearing sits at the base of the shaft.

Time to grease the track on the tone arm gear.

Time to oil the remaining components on the top side of the plinth. I put a drop of oil on the platter, idler, and tone arm gear shafts.

It is a good idea to put some grease on the gear at the base of the platter, before assembly.

An e-clip on the platter's shaft holds it in place. As you can see, I accidentally melted the platter's rubber mat during disassembly. 

The aluminum BSR logo center just slips in and under the center of the rubber mat.

The aluminum outer ring that graces the platter's rubber mat fell off during disassembly. I had to scrape off the old adhesive then remove the residue with denatured alcohol. 

I put E6000 all purpose adhesive on the back side of the aluminum outer ring. 

Then I positioned the aluminum outer ring in place on the platter's rubber mat, and held it down with five D batteries, in order to help it adhere.

The back side of the plinth, or base of the turntable, has many mechanical joints that need to be oiled as well. I oiled each and every joint then ensured they moved freely. 

The back side of the plinth also contains many gears that need to be greased. First, I cleaned off the old grease using a Q-tip dipped in denatured alcohol. Then, I applied new PFTE grease.

I Applied a drop of oil to the spindle and made sure all parts of it moved freely. 

Time to test the turntable assembly. I made the proper electrical connections between the chassis and turntable assembly, then propped it up on several 2x4 blocks, making sure that the mechanical parts on the underside of the plinth were not obstructed.  

Turntable Problem

After lubricating the turntable assembly, I had a curious issue in auto mode where the timing was off and the record would drop after the tone arm was already in position. I spent many evenings troubleshooting this issue, thinking that I either bent or assembled something wrong. On a whim, I decided to turn the spindle 180 degrees in its center mount of the platter. Like magic, everything started to work as expected with the record dropping first, followed by the tone arm moving into position. The spindle mount in the platter shaft has a notch, the spindle record dropping mechanism must align with this notch. 

Cassette Deck Repair

The adhesive that held the cassette keys in place had grown brittle through the years. When I pressed the Stop key the Play key would launch into the air. I used E1000 adhesive to glue all keys back onto their metal mounts. 

In order to get at the cassette desk mechanism and the electrolytic capacitors on the printed circuit board, you must remove it from its mounts. Three screws, circled in red, hold the printed circuit board to the cassette deck chassis. 

I replaced all of the electrolytic capacitors on the printed circuit board with new. 

There is also one electrolytic capacitor, circled in red, across the motor leads that needs to be replaced. 

There is a switch on the printed circuit board that is triggered by the cassette keys, via its mechanism. Access to the contacts within the switch can be obtained through its end. I recommend spraying some contact cleaner into it, then exercising the switch manually, so that the contacts are properly cleaned. 

In the cassette deck chassis, I put a drop of oil on all pulley shafts and then made sure each pulley spun freely.

I applied PFTE grease to any metal slides, after the old grease was cleaned away with a Q-Tip dipped in denatured alcohol. 

The initial issue was that the cassette player played the cassette at slower than normal speed and the cassette counter did not work. I had determined this was due to deteriorated drive belts. I replaced both of them with new drive belts I had on hand. I purchase drive belt kits on eBay that contain a variety of lengths. Most of these drive belt kits come from China so it takes awhile to be delivered to my home in the United States. Purchasing a drive belt kit from China is a lot cheaper than purchasing the individual belts from an electronic parts distributor.  

Time to attached the printed circuit board to the cassette deck chassis using three screws circled in the picture below.

Like the turntable assembly, I also test the cassette deck assembly out of the cabinet by connecting the proper electrical connections to the chassis, propping it up on 2x4 blocks then powering on the chassis. The cassette deck works a lot better now that the drive belts have been replaced.

Assembly

I treated the MC-3020's wooden cabinet, inside and out, to a coat of lemon oil. This is the best time to do it, with all of the electronics removed.

I then buffed the veneer with a lint free chamois.

Next, the chassis was reinserted part-way into the wooden cabinet from the front. 

I placed the turntable assembly in place on top of the wooden cabinet, then connected the power connection to the chassis. 

You must attach the turntable assembly's tone arm audio connections from the opening in the back of the wooden cabinet.

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The two clips that hold the turntable assembly to the wooden cabinet can then be installed.

Time to install the cassette deck. First, I fastened the AC Choke to the chassis with two screws. 

Then, I installed the electrical connector that connects the cassette deck assembly to the chassis. 

The cassette deck assembly was once again fastened to the wooden cabinet with four screws circled below.

I noticed the cassette deck was running too fast after assembly. I drilled an access hole that allows me to use a small jewels screwdriver to adjust the cassette deck's speed easily from the outside while it is in play mode.

Finally, I replaced the screws that hold the chassis in place.

Conslusion

Getting this vintage Fisher MC-3020 sure required a lot of work! Actually, it is not work if you really enjoy what you're doing. I thoroughly enjoyed getting this vintage integrated component system up and running again. As you can see, it has a place in my "wall of stereos". I will enjoy listening to cassettes and records being play on it while I work on other projects. 

My rebuilt Fisher MC-3020 Stereo in action!