Sony TC-K611S Three Head Cassette Deck - Rotary Encoder Repair / Belts 

Thank you! I have this same deck and the door would not open but belts were intact. Followed this video cleaning rotary encoder. Also replaced belts while i was in there and now my deck is working again. Thank you for the great video.

Hey that pen trick is clever! Will try that next time I lose one of those tiny washers :)

The proper adjustment of the rotary controller is probably why the unit goes crazy after replacing the belts. Thanks for this, I will revisit my TC-k615s. I'm sure it's the same issue.

Fantastic guidance and advice. Thank you much for your videos. Managed to re-belt my TC-K611S. Main Drive belt was completely perished, (liquid rubber!) Cassette open/close belt was streched so as not to work. So a very sincere thank you, please keep up your excellent work.

Thank you! Your video helped me replace the belts and clean the rotary switch in my deck. It’s a TC K-690, and the tape transport is very similar to the transport in your video. The entire process took about three hours, and now I have a fully functional three head tape deck.

Excellent video, I'll be repairing my own 611S soon. hopefully it will only need belts. I recently repaired my 615S , looks the same as 611S on the outside, But the mech is completely different. same as the W411. Turns out it needs a new drive gear for the mode motor as it dumps tape from the supply reel when paused or stopped. Found some high quality gears from Poland on Epay

Hey Paul, thanks for your videos. I’ve just repaired one of these for my uncle. Someone else had already been in it and the drive belt was replaced with two thin elastic bands something else had failed so I stripped it apart the gearing and works perfectly. Hats off to you Sir

Green stuff is called solder mask.

Wow, thanks for this, a guy put new belts on my Kenwood, I had exactly the same issue . 👍

This dude is a magician! Gr8 videos on this channel.

Hi, I have a TC-KA6ES in mint condition and use it quite regularly, if it ever needs a service, it's good to know there are people out there who know how to service and repair these HiFi cassette decks. Stewart (Irvine, Scotland)

thanks for the vids, I got my k611 to work, first i replaced just the main belt and oiled the capstan motor and it mostly worked but would not play, I then had to do a full tear down to the mode selector and clean the dirty contacts, all works fine now. no one else had been inside, so dirty mode selector is a thing as you said

Good video 😎 I've repaired a few of these but not had to take the encoder apart yet, if I do, I now know how to do it 🙂

Great well explained repair

Great video,thank you so much!!

I was able to disassemble the rotary encoder without unsoldering it from the board. On an untouched encoder, the four plastic pins are not originally melted, but are held in the holes only by friction. After removing the two screws, I just peeled off the cover using a small flathead screwdriver, carefully pushing it into the slot all around the disc. May become useful for those who experience difficulties with unsoldering.

That oil most likely Deoxit D5 Same problem with some CB radios that have encoders like that and you have to have some oil on the contacts to stop the oxidation. and use a pencil eraser when cleaning contacts not sand paper. other then that very informative video. Thanks.

Good job Sir 👍

I picked up a non-working TC-K670 at an estate sale for $20. Cosmetically it was perfect, so I figured new belts was all it needed. Wrong ... after replacing the belts, the head and pinch rollers still wouldn't raise properly for the play to start. The hardest part for me was desoldering and resoldering the pins of the rotary switch. I need more practice ! Anyway it works as good as new now ... thanks for a fantastic video !

You are very clever MAN, Thank you

Fantastic videos - I have a couple of these decks that I'm hoping to revive. Have you come across any issues with the tape type selectors ? Both decks I have aren't correctly identifying the correct type - for example one identifies any tape as Type IV ! Any pointers or things to check would be much appreciated.

Crazy, a lot of the mechanic is identical to my TC-KA5ES and 7ES. I always thought, when some parts crack I'm for all time out of luck in finding replacement parts. But if this non ES deck has the same gear and plastic parts, for sure other models have them, too.

Could the oil in the mode switch be dielectric grease? A couple of RU-vidrs put that stuff into these switches in VCRs. Talking about VCRs I'm going to try the pen trick on a pinch roller on a video that has lost the plastic washer and so is flapping about. Thanks!

Your close-up camerawork is excellent! How many arms do you have? Three?? 🤣

I have had this cassette deck that I bought used on eBay in 2006 that has barely ever gotten any use since I've owned it. My son brought to my attention that it won't play, which turns out to be the rotary encoder that you pointed out in this video. Is it possible to clean the rotary encoder with electronics cleaner without disassembly? I'm pretty certain that the transport mechanism has gotten quite dusty over the years from just sitting in my entertainment system without any use.

Hi. Very informative video thanks. I have this model and love it, but my unit has similar problem. It’ll fast forward fine, but only play or rewind for a second or so…. Is it the same fix? Would really appreciate your opinion as you seem to know your onions.

How do you adjust the speed on these critters? The service manual is no help at all, thanks.

Asking for help with my AiwaADF800 the photo sensor has clapped out. I cant find one anywhere the service manual says its a SP1-315-04-B this brings up nothing on google. Thanks in advance for any help if possible.

Do you know of the rotary encoder is the same in a Sony tc-ke400s deck? Mine is playing up as non of the buttons do what they should. Fast forward and rewind make it play and sometime makes only one real rewind which chews the tape up! Pressing stop does a similar thing too then the deck gets stick on the play positions and you can’t eject the tape until you turn the deck off and on again!

I have one of these with what I suspect to be a bad flywheel (I've had a look at it and it looks cracked and I can feel a bump on it), when I turn it on, I can hear a fast knocking sound and when I put a tape in and record, there's quite a bit of wow and flutter on piano and guitar music... I'd love to get either the bad flywheel fixed, or try to source a replacement. Btw it's a UK model that I bought on eBay, from the UK shipped to Australia. It also claimed to be "Refurbished" but now I know that it was seller refurbished...

What will you do when the door does not open and the belt of the dooropener is broken

Dobrý den dotaz dá se nějak ovlivnit tažná síla navíjecí kladky při přehrávání se hrne pásek ke straně většinou na začátku kazety děkuji za odpověď pm

Demagnetise the head re align azimuth clean everything re lube everything put new belts in job done

Hi, greetings from the other side of The Pond. I'm an amateur trying to fix my Sony tape deck. Have a look ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-Vl4vtEaArIs.html It's a TC-WR 820. Transports look similar to the one in this video except there are two transports and each has two capstan flywheels. Both transports will eject rewind and fast forward. But when I push play it stops. I've changed the belts and was very careful to align all the gears as shown in the manual. Checked and cleaned the mirrors. I haven't cleaned the rotary encoder. I'm wondering if it's possibly something else? Also before I took things apart I noticed the capstan flywheel washers were missing. You mention I can cut some out of a pen refill? seems it would be much smaller than the one in the video. I'll have to try cutting some. Any advice is much appreciated. And great video. Cheers Andrew