Repairing the Magnavox D8443 Boombox

Many of you have read my post about the Magnavox D8443 boombox which details my history of ownership, along with the state of that model boombox as it pertains to those who collect them today (http://vintagevolts.com/?p=328).

One of the biggest issues with these boomboxes is the deteriorating condition of some of the gears which drive the cassette mechanism. The gears are made out of an inferior quality of nylon which tends to turn very yellow (a form of oxidation), eventually turning brittle and breaking. When this happens, the cassette mechanism is rendered useless.

When I got my replacement Magnavox D8443 on eBay last year, it too had the same problem. I knew about its issues, but I was determined to get the boombox as cheap as possible and figure out a way to get the gear replaced. I did have the original gear, but it was missing some teeth and was broken in two. I tried to create a resin casting from clay so I can cast a replacement gear using a clear resin kit that could be found at most art supply stores. I found it very difficult to produce the gear mold. Nor was I able to conceive a finished product that would not have required a large amount of “finishing” in order to get the gear working right.

Replacement D8443 Cassette Gear

What ended up working for me was gaining access to high-end 3D printing system in order to get some “samples” made. So, I tapped my resources to create an accurate model of the original gear, then had a couple of gears made for me to test extensively. Version 0.9a of my gear design actually turned out very well. Not perfect, but very well. I was able to get the gear installed in my D8443 and run cassettes in it  over the next few weeks. I ran about 50 tapes through, both sides, and the gear performed wonderfully. Afterwards, I tweaked the design (version 1.0) and had more gears created. I tell you, this isn’t some cheap desktop 3D printing contraption doing it (as much as I WISH it could have been) because the resolution needed for the tiny gear teeth was beyond the capabilities of DIY 3D printing solutions. A high-end professional 3D printing system was used instead. The newer batch of gears were very detailed. I installed one in my D8443 and it worked just as well as the prototype design.

Now that it turns out to be a suitable replacement gear, I am making the gears available for sale to other collectors whose D8443s have the same issue. I have found a reputable manufacturer that lest me sell them at a lower price. You can now buy as many gears as you want/need here:

Magnavox D8443 Gear

I (hurriedly) produced a 30 minute video which details the disassembly of the Magnavox D8443 and replacement of the damaged gear. The video can be found at: http://youtu.be/p4YuYZVYIX8

34 Comments to "Repairing the Magnavox D8443 Boombox"

  1. Dylan says:

    Help me please! I’m having some trouble with my boombox. I have a magnavox D8443 and I had to replace the balance switch, the installation of that went fine, but when installing I had to remove a PCB with the radio tuner capacitor on it. The board goes on top of the big wheel gear seen below. I can’t figure out why, but when I place the board back together, the needle only moves about halfway the way it is supposed to go. The electric tuner rotates a full 180 degrees, but it seems it would need to move 360 in order to move the tuner needle all the way. Thanks.

  2. George Cox says:

    Could you please tell me where in the world could get the little bands that drive the cassettes. I know that this isn’t a boombox that you mentioned. You sound like you know what you do. the number is AZ9430GYL1 the serieal # 27765080. thanks for your help.

    • jeff says:

      If I figured the model number out correctly, that is a Magnavox (Philips) boombox.

      The information at this website should lead you toward what you need. Bands (drive belts) are something I order as needed for my own repairs and aren’t something I keep on-hand.

      http://www.turntableneedles.com/Belt-Measurement-Guide_ep_65-1.html

      Be prepared to take some measurements and determine the shape of the belt and the above store should be able to take care of your needs.

      Thanks,
      Jeff

  3. Carlos HANSEN says:

    Hi I Have a Philips Magnavox D6330 Portable cassette player and as far as I can make out from your video the gear that is broken on my model is exactley the same gear as in the magnavox D8443, is ther any way of being sure on this and would you ship a gear out to spain if this was the case…???

  4. jeff says:

    Hello Carlos,

    I apologize for the long delay in responding. I still haven’t got the notification feature of this website operating efficiently, and that has caused me to miss many responses.

    It is my understanding that Magnavox used the same cassette mechanism in many radio and cassette player models. I’m still learning all the different models that are affected.

    If it helps, the dimensions of the replacement gear are as follows:

    Overall diameter: 22.4mm
    Diameter of smaller gear: 5.7mm
    Overall height: 6.2mm
    Height of wider gear portion: 2.2mm
    Height of small gear portion: 4mm

    The height of the individual gear portions are not as critical as the overall height and diameters of the gear portions. Even so, there may be differences between the new gear and the original gear since part of the decomposition of the original gear changes its dimensions.

    I can add Spain to the list of countries that I ship to. I currently sell these only on eBay. But as I sell out each batch, eBay creates a new auction number. This is the current auction link:

    http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=231096108306

    I hope that helps!

  5. josh says:

    just became the new owner of one of these beauties. works fairly well, but not perfect. anything off the top of anyones head i should begin with? tape player DOES work, stereo issue when volume knob is moved, and generally dirty

    • jeff says:

      My volume control seemed “dirty” too, but it turned out to be broken. The metal contact slider in the control snapped out of its plastic mount and wasn’t conducting properly throughout the control rotation.

      I had do desolder the control from its circuit board, carefully disassemble it, and try to get every part back in its place.

      I noticed that plastic flanges were molded to fit in holes of the contact slider, but they were broken. I tried melting the slider into the plastic as a fix, but it didn’t hold up very well.

      I haven’t been able to find an exact replacement for the control yet, but I will still research it on occasion.

  6. Jenna says:

    All the gears are have broken teeth on mine so I need to replace them all. any idea where to get the other gears?

  7. Vasilis says:

    Yo! I sent you a message via youtube and this is a follow-up in that same breath.

    I got myself a Magnavox D8443 and I ran into the problem with this gear missing teeth and playback doesnt work because it cannot feed into the cassette (causing tapes to just feed into the cassette housing — yikes)…

    I am trying to get my hands on one of these bad-larry’s because I would do anything to get this cassette player up and running to complete this re-build.

    It seems like you are the only source to acquire one of these little gears and you are a hero.

    I will keep looking back to this thread in the next few weeks and sporadically throughout time in hopes to be able to trade information and keep myself updated with your inventory.

    Cheers!

    • jeff says:

      I’m still wondering why I my website isn’t sending me notifications for the new posts on this thread. Otherwise, I would have responded much sooner.

      I am working on getting another batch of gears delivered sometime within the next two weeks. I will post them for sale either on this website or on eBay when they arrive and I check them for accurate design specifications.

      • Vasilis says:

        Thanks for the reply Jeff. I was getting a bit worried about when I would be expecting some feedback. (I didnt recieve any notification either via E-mail about this reply.)

        I will find a way to ensure that I can purchase one of those gears as soon as they are up for sale.

        Thank you so much for doing this and if/when I rebuild the D8443 I will let you know how the cassette player turns out.

        Cheers

  8. RANDY GREFF says:

    I just used your gear to fix the tape player – I new the gear was wasted as I have owned a few D8443s. I had it done professionally. Now they are telling me that the motor is bad. Is that also common? What motor do I need if that is the case? The say the motor is getting power but not spinning.

    • jeff says:

      I’m afraid there are very few details about the D8443. Thank you for purchasing the replacement gear and I hope it installed well for you. As for the motor, I don’t have any resources for part numbers. If I were replacing the motor, I would remove it and look for any part numbers that may be printed on the motor body. It’s not unusual for the same motor number to be used in other radio models from the same manufacturer. You might need to find a “parts boombox” to salvage parts from as needed.

  9. Angel says:

    Hi! When will it be possible to buy more of these gears on eBay as of 2016?

    • jeff says:

      I’m still waiting for a new batch to be manufactured. I expect to get them closer to the 25th of March. Thanks for inquiring!

  10. BURTON KENNEDY says:

    How do change a drive belt on MAGNAVOX – D8300 BOX? The cassette player won’t play but gets power..buttons work.How on average does one cost for repair?…cost of parts?…labor? Where do you open it up at? Is worth the hassle of fixing? Where in HOUSTON, TX.77041 can I get it fix at?

    • jeff says:

      I understand your situation, but please bear in mind that this site is dedicated to the appreciation of vintage electronics. Unfortunately, I don’t detailed have knowledge of repair procedures unless I had to do the same thing myself.

      Perhaps other visitors to this website may be able to chime in on this discussion and offer advice.

      The D8300 is, of course, a different design than the D8443, but it shouldn’t be too difficult to adapt basic repair procedures to it. Most boomboxes had case screws all around the back perimeter. These usually were at the bottom of deep holes. Some screws may be on the surface of the case, while others may go along the middle of the back case. You may even find a screw or two in the battery compartment. If the D8300 is designed similar to the D8443, then after all case screws were removed, the back cover should just lift away. You might need to lift slowly so you can see if any antenna or power wiring is connecting the case back to the internals.

      I cannot find any pictures of the D8300 internals, so I won’t be able to guide you any further. If you get yours open and want to post detailed pictures of the inside, feel free to do so on whatever image hosting site you wish, then post a link to the picture(s) here. As for getting it repaired by someone else, a quick Google search should turn up some resources local to you. Houston is a big area and I have no doubt that there is someone who specializes in the repair of vintage radios, etc.

      As for the cost and value of getting it repaired. Unless the boombox had been prominently featured on a cult 80’s movie, or was prevailingly popular at the time, then it’s probably not worth too much. Unless you repair it yourself, labor rates can be prohibitive. At that point, you must weigh repair costs against its nostalgia value, as in, “What is it worth to YOU to get it fixed!” It may be cheaper to buy a working version on eBay and hold on to your current one as a source for spare parts.

  11. william Richard says:

    I need a Battery door for my Magnavox D8443 , I can’t find one on e bay . I’m lost on finding one. Please help.

    • jeff says:

      I don’t know where to get any of the other parts for the D8443. The gear in the video/article is the result of necessity and capability. I can have small items like the gear made rather cheaply. Larger items will be more difficult and could be very costly to have manufactured. It may be cheaper to get another D8440 that has a battery cover and hold onto it for spare parts if anything else goes wrong.

  12. Jared says:

    When do you think you’ll have more gears made? I check the site and eBay and I missed out.

  13. Adam says:

    Hello. I am also in need of this gear. Will more be available any time soon?

    Also, another small part I need is a power button. Just the small black part. Is this something you would consider duplicating as well? Or should I look for other options on this?

    Thanks in advance.

  14. Jim Nuss says:

    Sir, I bought and fixed someones D8443 using one your new gears, thank you. But now the gears for the fwd/rew have “failed” anyone know where to get new of these??

  15. tony says:

    hi, can you point me in the right direction to a place were i could buy the rubber belt (band) ? mine has snapped and needs replacing, hope you can help

    • jeff says:

      I don’t know of any specific source for the belt. I actually used a “Silly Bandz” in mine, which just happen to have a square cross section like the original belt. I just picked one that was the most rounded in shape and provides moderate tension. https://en.wikipedia.org/wiki/Silly_Bandz

    • Dylan says:

      Hey, i don’t know if you’ve found a replacement yet, but if you take the old band and lay it out in a circle and adjust it so that the circle is fairly perfect – you can measure it with calipers (or a ruler if need be) and you can use that diameter to find one on ebay. It worked for me :)

  16. Ritchie says:

    Hi, it’s great that you’ve found a way to create this gear and made it available to other collector’s! I really want my boombox working again, is it possible to ship it to the Netherlands? On e-bay it says it will only ship to the United States

  17. Peter says:

    Hi do you have any more gears for the d444 many thanks

  18. Dylan says:

    Hi, do you have any more gears in stock now for the magnavox/ phillips boombox’s, or will you any time soon? Thanks

  19. John says:

    Do you plan on getting any more gears to sell on eBay for the Magnavox d8443?

  20. Dylan says:

    Is anyone alive out there?

  21. Dylan says:

    Hi! Do you have any gears for sale, or do you plan to any time in the future? PLease, if you have any info at all, I’d be extremely grateful. I’m hanging on a limb here

  22. Michael says:

    Any updates for 2019? Is the gear still available? Thank you.

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