"Cheese" Gears inside a Philips D6920 portable cassette deck

In the 1980s, Philips used a rather soft material for cassette mechanism gears. This video documents the consequences.

[@noelj62]

3D printing may fail because the shape of gear's teeth is impossible to perfectly reproduce.

[@Hagledesperado]

Perfectly? Yeah sure that is of course impossible. But I think "well enough" would certainly be possible. But measuring the gears and modelling them in 3D would take an hour or more unless you're a wizard. And having them printed with sufficient resolution in a material with sufficient strength would probably cost as much as you could sell the entire repaired unit for. So probably not worth it. Unless you're either doing it for the sheer challenge of it, or you already have professional equipment and skills at your disposal.

[@alferro3149]

Gears and belts are pretty easy to find on eBay. The player actually has a very nice sound(from the rca out). The woofer quality doesn't really matter, it's used just for monitoring.

[@SvensonGielen]

I made these resin gears into my Philips D8614.For two years he has been working great!

[@SvensonGielen]

@Big_Paul In Poland, you can buy ready-made sets of these sprockets at one auction site

[@Lagib28]

I remember when parts like that were made of much more durable nylon. Those days are long gone.

[@riverhuntingdon6659]

The later Philips machines were pretty horrible. In some cases, it's possible to use nylon replacement gears, I've done that on a few 80's boomboxes. There's an outfit in Holland that produces some of the gears, MFBFreaks, from original undamaged ones. Other things to watch out for are erase heads that disolve. Can quite understand why you dumped this one. Motors might be worth keeping, the capstan one fits many other older Philips machines.

[@raymondleggs5508]

Why would an erase head desolve?

[@039dalekmoore2007]

I just fixed mine today i have the MK 2 yes they used the orange gears as well i found some replacements in old printers just grinding them down into shape now works great

[@multiro_r.leaves]

dalek moore can you tell in detail, how you managed to find the replacement, or send me a message? I have the MK2 and have just encountered the cheese gear problem

[@andreaporcu4702]

Me too...please

[@darkubarku]

Great review. I bought the same tape recorder a few months ago, but it has been completely refurbished, gears and belts replaced with new ones, cleaned interior. It works great and is a very good tape recorder. Yes, it is full of plastic, but the sound records and plays well. However, buying these parts is much easier today than it was five years ago. The sound is even better (I think) than in my ITT Schaub-Lorenz 740AV, which is a similar tape recorder. I had a choice between the D6920 and the D6920 MkII, but the older one is nicer in my opinion. Regards.

[@superhavi]

My post may be to late for this cassette recorder, but if you ever encounter a similar problem, there is a solution. There are many companies, that sell custom made gears. They only need to know the outer diameter and the number of teeth. Those companies mostly serve to model builders and classic car enthusiasts, and since they have many gears in store those replacement gears ar mostly cheap.

[@multiro_r.leaves]

superhavi can you please share the links? Thank you

[@andreaporcu4702]

Yes share it thanks

[@38911bytefree]

Happens a lot in Grundigs ... CN850 and RR900 boombox with the same crap. And Technics Decks from mid 90s, at least the ones with manual doors. I talked to a Panasonic Tech here ... they are called "fuse" gears (to protect the mechanism) ... LOL.

[@Bus2000]

Philips used a lot of plastic to keep the weight as low as possible (portable). We had this recorder at school in the early 80 so for me it's nostalgic to own one. The gears where made of hard plastic but they get soft after a lot of years. Just like some erase heads Philips made in the 70s.

[@Bus2000]

I did draw (1st time for me) with help of youtube examples with FreeCAD the gears. Once printed on a professional 3D printer the recorder plays fine again so it can be done.

[@codebeat4192]

Philips used a lot of plastic to keep .... the costs as low as possible because it is so easy to produce plastic in any shape required and yes it is a very light material. They also made speakers with a plastic frame, really! They really love(d) plastic. The gears in question where not made of hard plastic because they used a softer plastic to reduce mechanical/gear rattle noise especially useful for ingage gears. The erase head problem isn't just a 70s problem, it is also present in devices from the 80s. The problem is not the plastic housing but the epoxy/resin/whatever to keep the coil and iron core in place.

[@rarbiart]

Wir haben früher bei Gehado in Dortmund immer gewitzelt, die Fabriken von Philips für die braune Waren seien in Wirklichkeit nur Alibi-Betriebe, um eine riesige Rieseninvestition in eine Spritzguß-Plasteteile-Fertigung möglichst lange zu kaschieren, indem deren Output irgendwie in Jubelelektronik verbaut wird.

[@serratusx]

there must be people who will create a printed replacement based on the original component. it would be a shame to ditch the machine for the lack of that one part

[@DrCassette]

Those people sure do exist, but they want to be paid for their work, you know.

[@command8783]

I'm copy pasting this comment from someone else: "Not only Philips boomboxes have this issues. Quite a few higher end Philips models have the same orange wheels, and a Dutch site MFBFreaks.com now sells kits to replace the gears for a few decks. All of them are made with moulds the website owner made from original undamaged orange wheels. We on the MFBFreaks forums call it the "Orange Wheel Plague"." - Daniël's Tech & Music Channel MFBFreaks.com happen to have the D6920, Im ordering a set for my N2206, if you want I can keep you updated on when I get their sets to tell you of the quality if you want.

[@RuneTheFirst]

This is gigantic news - if they are of decent quality. Did you ever report back?

[@Erdertainment]

They don't seem to have the gear for this particular device, sadly. :(

[@stevedoubleu99B]

I have the mk 2 model, I will have a look and let you know if I have cheesy gears Doc.

[@DrCassette]

Thank you very much, that would be very interesting to know. I like this recorder, but the cheese gears are a massive problem.

[@stevedoubleu99B]

DrCassette Hi, I've just had a look and the cheese gear still exists in Mk2. I wonder if it is designed to break in case of jammage, to avoid further trauma to the mechanism?? But what do I know...ha ha.

[@DrCassette]

Thanks for the info. Now the MK2 version is also off my wishlist. Too bad. I don't think these gears were supposed to be a safety feature. They probably used a material that was cheap and easy to work with, only to find out later that this material is not stable over a long period of time. The same thing happened with the belts Philips used in the 70s, after some years, they disintegrate and turn into a black liquid!

[@MilanCekic]

Thank you, Dr. Cassette and steve doubleu.... for saving my money and time, I almost bought this device yesterday (cca 35eur in my country), unknown condition, but the owner said "there`s some flutter while playing"... so decided to do some google searching before purchase... luckily I found your video and comments, very informative and useful... best wishes to you!

[@TheTrueVoiceOfReason]

You mentioned River, formerly AG3304. Is this the older gentleman in England who loves repairing old kit? If so, do you know if he is still on KZbin? His channel disappeared from my list and is sorely missed. Thank you.

[@DrCassette]

Correct, he has a new channel: kzbin.info/door/4Oy50wzhsNNwn2pEu0iyFg

[@TheTrueVoiceOfReason]

Thanks! Also found his tribute channel via his old name. And thank you for your excellent videos.

[@TheTrueVoiceOfReason]

@Big_Paul yes, it was sad to hear he had passed. River had done his annual All Hallows Eve show where he spun tales of eerie account. Then nothing until his lady friend (not sure if they ever made it official) announced his passing on his channel. A big loss in his style of entertainment and knowledge of how to repair such vintage kit. I still go back and enjoy his videos on that channel and the tribute channel, which I'll link in a moment. kzbin.info/door/Cy3XJtwayOXb2YGvv76nWg Peace, River.

[@kennynvake4hve584]

I had the same kind of gear problem in a Technics cassette player...the gear was on the arm that would move back and forth to engage the ff and rewind that goes into the cassette hubs to spin them...they were an orange color and very soft just like yours.

[@SteuSax666]

Hi! I bought a BoomBox Phonola Compo TR4883 in 1983. It worked fine until last year when it became to eat the tape. Yesterday I decided to examine it and I discovered that it has the same mechanism of BoomBox Philips D8438. Even the external case looks the same! Now...it doesn't work anymore because the damned orange gear: it's a mold gum, now. Do you discover if anywhere there is a new resin gear like this one ?

[@codebeat4192]

Yep, i have the mark II version and same problem however on this one the front gear (between both drive wheels) is broken into 3 pieces. There is also a metal spring that looks broken, it must be attached to the gears in the middle. I found this video because I searched on this issue on google. It seems a typical Philips/Magnavox problem, mostly all of the decks of that era seems to have these cheesy yellow/orange gear problems. So better avoid these decks or start a business by reproducing these gears ;-)

[@rastaman5105]

I have the Philips D6920 MK2 , and it has the same gearsystems , that,s to bad , greetings from the Netherlands and i like your youtube video,s !!

[@DrCassette]

Some time ago I bought a Philips D6920 MK2 cassette recorder, it also has bad gears. I want to try some of the replacement gears available on Ebay for these recorders.

[@TheVCRKing]

Wow... Why didn't they just use regular plastic gears like most cassette decks do. God, even the Tanashin made decks are a whole lot better than this.

[@twoexem6548]

I may be a little late, but I fixed one of those decks recently. With new replacement gears, the mechanism runs good as new. Playback quality is decent, and the record quality is very good in comparison to my ITT Schaub-Lorenz SL 55. I might upload a video of it running sometime.

[@DrCassette]

Yes, now I know there are replacement gears available for this recorder

[@fotbollsbrud]

It would be fantastic with an update with step by step instructions of how to replace these gears!

[@armike669]

I just realized that philips themselves created the compact cassette and the machines they made are trash! Ironic :0, I have not come acrossed many Philips machines. However, there was this one boombox I tore apart. I can’t remember the manufacture or model but it did have at least one “cheese” gear. I took all of the gear teeth off! NO effort!

[@UHF43]

Philips used to have very innovative technologies, but at the same time they were pretty concerned about cost cutting methods. So they ended up selling very innovative yet totally trashy products. I think there is not a single Philips mechanism of any kind that has withstood the past of time.

[@JohnBoonBeanDutchman]

@@UHF43 I still use my Philips from 1978 or 9, it,s call black tulip stereo tower Made in Belgium, nothing plastic Have also still the speakers 50 years off Guarantee,. not even had to recap anything, but yeah, this thing on the video looks really shitty to me, I,m wondering what country it is made, later yearsThe innovative technologies get to stay,s in Eindhoven, the most production gets too lower labor country,s, and some times it looks like those days,s looks as some brand names maybe get sold

[@badscrew4023]

Too late, I've got one too :))) With the same problematic cheese gears of course. These days it's possible to find the replacement gears that aren't 3d printed - which I did. Waiting for them to arrive, will try to restore this deck...

[@DrCassette]

Good Luck!

[@WaltonPete]

I wonder whether the grease used to lubricate the gear is the real culprit here. As you're probably aware, some plastics are degraded by petroleum based grease and this wouldn't be the first time I've come across just such a problem. I don't know if silicone grease or similar wasn't available then or was too expensive to warrant use in such a device but obviously it would be used today to avoid the problem.

[@DrCassette]

This could be possible, I don't think the material is supposed to be soft like this, or soft at all.

[@pmr1wrt53]

In the eighties I bought this deck new and used for live recording of music. The price was a little expensive, maybe overloaded. I sold this one and bought many years later in 2011 a used one. My Philips D6920/00 has an ALPS K25E tape head. This head has 8 solder connections. Yesterday I take a quick look and this deck have the same problems that mentioned in this 'good' video. Thanks for sharing. Edit: See imgur.com/OYlzIeN and imgur.com/O78PQDe for the ALPS K25E Tape head

[@JohnBoonBeanDutchman]

Amorphous Heads are supposed to wear slower and last longer than older heads. Also, they have a clearer treble than some others many manufacturers switched to amorphous heads late in tape deck production life around the late 80s and later.

[@nt654321]

Sometimes I really wonder how Philips managed to stay in the hifi business for so long (and even manufacture most of their stuff in Belgium), when the build quality of their products clearly was extremely inferior compared to the Japanese equipment of the time... Without their CD player technology, they would probably have ended up like most other European hifi manufactures in the 1980s :)

[@DrCassette]

They were the first european company to really cut down on quality. That way they could offer equipment at low prices...

[@jasejj]

DrCassette Well not really, the British manufacturers were masters when it came to making stuff badly... and they suffered accordingly. Philips just happened to be larger so took longer to die off. Some of the stuff Philips made in the 90s made the early Korean stuff look classy.

[@DrCassette]

Philips is from Holland ;)

[@jasejj]

I know. Just pointing out there were European companies (and despite the best efforts of the Right-wingers in the UK, Britain is still a European country!) further down the road to being rubbish than Philips in the 80s :-) And it has to be noted that quite a lot of Philips's output was British-engineered in any case. Those old G8-chassis TVs from the 70s for example, terrible old things, and engineered in Southampton...

[@JohnBoonBeanDutchman]

@@jasejj Philips is more specialized in the electronic aspect of the product, probably less in the mechanical part unfortunately

[@command8783]

I have a phillips N2206 Automatic Cassette recorder, Mono Boombox w/ lineout with the main power transfer "Cheese" Gears also falling apart, Do you know of any way for me to get a replacement?

[@masterargento90x]

The more sophisticated the deck is, the more difficult it is to get replacement parts, and the more difficult it is to repair. Seeing how complex the mechanism is, no matter how cool it looks, I definitely wouldn't buy such a deck.

[@kyfeam]

there is a simular issue with the Magnavox D8443 boombox.. thankfully there is a seller that does make an excellent copy of the gear needed for the boombox..

[@chrissanders2562]

I just got one of theese boomboxes and all of the gears are crumbled.

[@codebeat4192]

I can confirm that the MKII has the same issues.

[@DrCassette]

That is very unfortunate... at lease there are replacement gears available now.

[@raybokor2]

thanks for this i was looking at one on ebay with the same problem. shame there a nice looking unit

[@raybokor2]

kzbin.info/www/bejne/omeXY4J_g8uqfMk worth a look

[@DrCassette]

They successfully printed the smaller one of the two problematic gears. No idea how they could print a replacement for the big tower gear.

[@38911bytefree]

Thanks for the advice, I was considering this machine that poped in an online site locally. I cant stand the rich features with a soa crappy transport. One advice AWAY from printing anything is, if FWD take up spool has a polly to drive a belt (counter) you can put a small motor somewhere and move the take up with a belt. At least you can solve it for play. I did kinda of this on an UHER REPORT whit a long gone motor .... Well, for take up on play, I put feed the motorwith at constant current. Im not sure if this the best option. It did the job ... barely .... I used tow motors for the report actually, back to back... long story. The capstan motor speed contorl is already blown LOL

[@estibahipelcanel]

Hi , had the mk2 with the same problem, i keep finding used cassette gears that get unusable really quick it drives me nuts, which portable cassette deck with the same kind of features than the philips would you recommend purchasing ? or which brand is trustable in time ??

[@DrCassette]

Good and reliable HiFi stereo portable cassette recorders are very expensive now. The Sony TC-D5 series of recorders is excellent, but sometimes even these recorders have problems, and they are extremely expensive.

[@estibahipelcanel]

😰sad news but thanks for yr answer !

[@SibaNL]

Same problem with my Philips FC144

[@DrCassette]

This is unfortunately a common problem with a lot of Philips equipment of that time...

[@enricoself2256]

Unfortunately most of philips cassette decks are plagued by the same problem, gears made with that translucent plastic which simply disintegrate with time. Oddly enough their later DCC decks are also very good cassette deck !

[@petersopacua9349]

Yes the Philips D6920 Mark 2 has the same gearsystem to !!

[@DrCassette]

That is very unfortunate. At least there are now replacement gears available online.

[@serg1639]

The gears can be printed on a 3D printer.

[@RanFuRe]

nice one.

[@W00fer]

serg1639 this small? Don't know if that will work on a sub 1000 printer.

[@serg1639]

It is necessary to try to make. Here's a guy in the amplifier input selector fixed it. vk.com/club122241235?w=wall-122241235_446

[@codebeat4192]

Maybe on an expensive printer (with very accurate pwm sine) or a resin printer. A regular printer cannot produce such fine details.

[@mdftrasher]

In dutch "de gele tandwielen pest" See: forum.mfbfreaks.com/viewtopic.php?f=5&t=8061 A lot of things are tried, there is no solution yet.

[@rajivdogra1250]

all videos great good informatine nice work

[@dorfschmidt4833]

Philips hatte bei mir noch nie einen Eindruck der Hochwertigkeit gemacht. Nehme gerade ein rund 40 Jahre altes Objektiv auseinander, es ist vollständig aus Metall und Glas gefertigt. Moderne Objektive sind zumeist aus Plastik gebaut, um den Profit zu maximieren. Plastik = Wegwerfprodukt.

[@DrCassette]

Ich würde auch sagen, Philips war die erste europäische Firma, die auf den Billig-Zug aufgesprungen ist. Die Zeit hat ihnen leider Recht gegeben, denn anderes als Firmen wie Grundig, Nordmende, Saba usw. ist Philips bis heute eigenständig...

[@abdelkaderelbachir9523]

The mark 2 uses the same exact mechanism and pretty much the same internals

[@DrCassette]

So it will most likely have the same fault. That's too bad!

[@abdelkaderelbachir9523]

@@DrCassette You know 3D printing is always an option is not easy but it is possible

[@DrCassette]

No, 3D printing presently is not an option for me.

[@chucku00]

"I make a new one" - My Mechanics

[@DrCassette]

These days replacement gears are readily available on Ebay.

[@stevedoubleu99B]

You won't believe this one, how about an erase head that lets one of the pole pieces drop out 'cos the resin has gone soft!!! I kid you not, I will post a video on utube shortly. (On a mk2 machine) 'Philips erase head wierd event'

[@DrCassette]

I do believe... Yes, there are even heads that go bad due to the use of low quality materials.

[@HDXFH]

Cut it off level or glue up a custom gear from plastic

[@RuneTheFirst]

My first thought. Years ago I had to have some parts duplicated by a machinist. The original factory parts in a motion picture projector failed at the drop of a hat. They started out clear and quickly turned dark brown and failed. Brass parts solved the issue. I have, in desperate times, made gears from ABS sheet - by hand. I don't relish doing it but if it is the only way...

[@rastaman5105]

I have The MK2 version of This Philips D6920 !!

[@DrCassette]

Unfortunately the MK2 version has the same bad gears as the original version.

[@rhysevans8691]

it would be a good idea to ask someone to 3D print one to fit it.

[@publicmail2]

Looks very cheaply made, from mechanicals to electronics. You never know someone might have these gears still in the package "new" since a common failure, maybe even subbed over to made from normal plastic.

[@alcoholisfreedrink]

definitely ''high-end'' cassette deck. Philips is good at using plastic. I had philips all in one portable stereo. After 2 months of usage it ate brand new sony hf 90 cassette tape! This cassette player rolled the tape around the capstan somehow... Later i had philips combo system which had plastic flywheel. Absolutely no metal on it!