Tapeheads Tape, Audio and Music Forums
High quality analog audio tape for professionals and enthusiasts alike.

Go Back   Tapeheads Tape, Audio and Music Forums > Tape, Taping and Tape Machines > Cassette > STICKY - Cassette Decks and Tapes

STICKY - Cassette Decks and Tapes This section is full of helpful posts. Repair, how-to, techniques, tutorials.

Donate to Tapeheads!
Reply
 
Thread Tools Display Modes
  #1  
Old 02-01-2014, 08:20 AM
hossomat's Avatar
hossomat hossomat is offline
Serious Tapehead
 
Join Date: Apr 2010
Location: Frankfurt, Germany
Posts: 105
LONG: How to change the mode belt on a Sony TC-KxxxES deck

(You may want to make this a sticky post)

Howdy,

many users have asked what to do when their Sony TC-KA6, K770ES, 870ES or 909ES wouldn't play back. It would rewind and fast forward, but as soon as you pressed the play button, operation would stop and most of the time, a squeal could be heard.

Culprit is the so called mode belt which is driven by the cam motor, which in turn is turned on as soon as logic control says "change mode".

This belt gets slippery with age, sometimes even melts (newer models), gets longer, i.e., time for a change.

Most people, when they change it, take apart the whole mechanism and have to re-aling the left (supply side) pinch roller - pretty much of PITA.

This thread is to show how to change the belt WITHOUT having to do this re-adjustment. Just follow the steps in this write-up (example: TC-K555ESJ, the wholy grail of Sony decks, next to the K777ES (II) and KA7ES, if you ask me):

This is the deck (no fancy pic, just the facts, Ma'am):



Before you start, you may want to open the cassette compartment and remove the lid and, to make it easier to remove the mechanism, remove the dark grey cassette holder (pls refer to pictures further down): The mechanism will then take up less room and be easier to take out of decks like K950/970/990ES etc..

After taking off the lid, you unfasten the screws holding the mechanism (arrows), you may want to undo the screws next to these so it gets easier to remove the mech when you get there.



Next: Remove the two screws on the bottom (arrows), undo the screw with the yellow arrow, it might get in the way later.



Next, you have to unplug all the wires that lead to the heads and the mech:

Start with the playbackhead:



Remove the upper pcb (8 screws) and remove the rec and erase heads' plugs:



Push the mechanism towards the inside of the deck, remove these three plugs:



Wiggle out the mechanism (easier with decks like K909ES or 890ES, there's more room) and start disassembly with the stabilizer. Use a screwdriver to carefully pry the holder from the metal bracket:



Hold the stabilizer like this so that when you pull it off, the stabilizer arms won't come off (no worries, you'll have to do some puzzling to get it back together if you don't heed this, funny little diversion):



For easier access to the screws, you may want to remove the bracket holding the stabilizer, start with the small bracket held back by the spring and then remove the "axis-rivet" that holds the bracket:



Bracket removed, now remove the plastic shield with the backlight (two screws and push up the clamp/cassette compartment lock:



Shield removed, take off the four screws that hold the diecast metal frame for the capstan drive:



Turn over, remove caspstan pcb and capstans (carefully). Remove arrowed screws holding the mech pcb (might be one more screw invisible here, you'll find it):



This is the mode belt:



The pcb board now has to be pushed away from the mechanism ever so slightly so that you get just enough wiggle room and gaps to be able to take out and change the belt:







Old belt, new belt, shiny, longer, old vs. matte, smaller, new:



New belt back in (30 seconds):



Reassemble and you're almost there.

While you're at it, use contact cleaner to get those tape selector, tape in and record tab switches back in shape. Edit: Use utmost caution when removing the clear plastic covers from the tabs as they are held by small tips/protrusions (half a millimetre in size). Break those and you need a new switch - no glueing!



Stuff I'm using (excellent results, also good for cleaning rubber contacts from remotes and bad pots):



As I said, careful with those tabs, they have small tips holding those clear plastic covers, you have to pry them open and not just pull!



Reassemble, just go back the way you came

Almost done, testing the unit: Utter joy!

__________________
Sony Decks-Tapehead: TC-K777/777ES/777ESII, TC-K88B, TC-K700ES, 730ES, 808ES, TC-K555ESJ (ch), DTC-2000ES (ch), DTC-1000ES, CDP-R3, X55ES, CDP-502ES, CDP-701ES, DAS-702ES, TA-E + TA-P9000ES, SCD-XA777ES, BDP-S5000ES, Nakamichi Dragon, RX505, Technics SL-1210 + AT-33PTG, T+A P2000AC + 2x A3000 power amps, Infinity IRS Sigma + Kappa Center B, Renaissance 80, ELAC Dipol 60, NEC-XG852 w/ Moome-Card

Last edited by hossomat; 02-01-2014 at 11:28 AM. Reason: addition, corrections
  #2  
Old 02-01-2014, 10:40 AM
eclectiktronik's Avatar
eclectiktronik eclectiktronik is offline
Serious Tapehead
 
Join Date: Aug 2010
Location: Madrid, Spain / Wirral, UK
Posts: 1,857
Fantastic, great work!
__________________
---
"This is recorded on sticky tape and rust! This is recorded on sticky tape and ru...."
  #3  
Old 02-01-2014, 11:11 AM
Pacific Stereo's Avatar
Pacific Stereo Pacific Stereo is offline
Sendust for brains
 
Join Date: Feb 2010
Location: Somewhere in paradise!
Posts: 12,094
Very nice write-up. I would caution all who consider taking those switches apart that this can be very dangerous. The protrusions that hold the clear parts on are exceptionally easy to break. When you break them, the switch will need to be replaced.
__________________
pacificstereo.net "Make your own kind of music!"



I RESTORE VINTAGE AUDIO AND VIDEO GEAR. Master technician for Concept, Quadraflex, Calibre, Pioneer and Sony. Endorsed by Richard Schram for Concept product restoration. Factory technician for both Yamaha and JVC. Sonics consultant for Denon. Pacific Stereo store manager, service manager, Central Service lead tech, liquidator at our demise. Pacific Stereo curator. Infinity IRS dealer. Music buyer for one of the first CD retailers in the USA. Authorized servicer for virtually every brand on the planet at one time or another. Music addict. Mastering & recording engineer, weaned on a Neve (no other console sounds like a Neve!). Industry-respected ears. Head Tapehead.

Need vintage audio & video repair and restoration, or unobtanium semiconductors and parts? Ask me! And do visit the website: pacificstereo.net
  #4  
Old 02-01-2014, 11:16 AM
hossomat's Avatar
hossomat hossomat is offline
Serious Tapehead
 
Join Date: Apr 2010
Location: Frankfurt, Germany
Posts: 105
Thanks for pointing that out more clearly, maybe a closer picture of the tabs would have made it clear how delicate those small tips really are. I wrote a small sentence to cover that as I broke one of those tabs myself sometime ago in the past but luckily I had a parts donor.

BTW: I got the replacement belt from A.N.T.

Edit: I included another caution comment in the instructions to make this aspect more clear as to what we're talking about.
__________________
Sony Decks-Tapehead: TC-K777/777ES/777ESII, TC-K88B, TC-K700ES, 730ES, 808ES, TC-K555ESJ (ch), DTC-2000ES (ch), DTC-1000ES, CDP-R3, X55ES, CDP-502ES, CDP-701ES, DAS-702ES, TA-E + TA-P9000ES, SCD-XA777ES, BDP-S5000ES, Nakamichi Dragon, RX505, Technics SL-1210 + AT-33PTG, T+A P2000AC + 2x A3000 power amps, Infinity IRS Sigma + Kappa Center B, Renaissance 80, ELAC Dipol 60, NEC-XG852 w/ Moome-Card

Last edited by hossomat; 02-01-2014 at 11:30 AM. Reason: amendment
  #5  
Old 02-01-2014, 11:59 AM
nikkit nikkit is offline
TapeHeads.Net Member
 
Join Date: Sep 2010
Posts: 48


Thanks for this great how-to. I still wouldn't risk doing it myself (two left hands with thumbs only) but it's great to know how I would have to.
  #6  
Old 02-06-2014, 03:48 PM
backtension's Avatar
backtension backtension is offline
TapeHeads.Net Member
 
Join Date: Apr 2013
Posts: 36
THX

great tutorial, because a lot of these ES decks suffer from that little belt.

  #7  
Old 02-12-2014, 02:59 PM
julks's Avatar
julks julks is offline
Serious Tapehead
 
Join Date: Oct 2013
Location: Japan
Posts: 202
nice to see this becoming a sticky.
but I want to add a common mistake people makes by doing this.
this is the "easy way" to replace the mode belt, and by doing this way, you must clean the belt and the pulleys after replacing the belt, because it will be full of grease.
and now you're good to go for another 10 years or so.

about the tape type sensors, to pull out the little plastic cover to clean the terminals, you need to "open" the cover before pulling them, try to do this with your thumbnails, and gently pull the cover. open the cover until you feel it coming out easily, not too much because you'll break the cover.
if you don't open it, no matter how careful you pull the cover, certainly one or two of them will be damaged.

another thing you would like to do, is to replace the 16V 10uF (2) capacitors on the control board of the DD capstan motor, they will almost always be giving up, leaking the corrosive acid. if you leave it, the motor will become unstable, spinning at wrong speed, and the traces will be damaged.
  #8  
Old 04-25-2014, 10:46 AM
teknacal teknacal is offline
Serious Tapehead
 
Join Date: Nov 2013
Posts: 206
Frustrated If Your Lucky

So riddle me this what do you do when the problem was created by the mode belt slipping, you then have to disassemble the transport and try to line everything up to get it to work. My problem child TC-K707ES has this problem and to add insult to injury there is no line on the mode cam to align the selection lever to. I have replaced many belts on my other decks and decks for friends and this one is the absolute worst to work on. Maybe its because of my age but I don't have the time to take this transport apart 3 or 4 times to get everything in alignment so it will work. I remember the good old days when manufacturers used to key parts so there was no guesswork but that costs an extra penny. My other pet peeve c-clips and plastic washers that will fly 50 feet through the air and are next to impossible to find. So the Sony may become my next paper weight, anybody else run into this problem of no line on the mode cam for the selection lever.
  #9  
Old 04-25-2014, 11:45 AM
draudio's Avatar
draudio draudio is offline
Serious Tapehead
 
Join Date: Mar 2014
Location: Cleveland, Ohio
Posts: 1,150
Quote:
Originally Posted by teknacal View Post
So riddle me this what do you do when the problem was created by the mode belt slipping, you then have to disassemble the transport and try to line everything up to get it to work. My problem child TC-K707ES has this problem and to add insult to injury there is no line on the mode cam to align the selection lever to. I have replaced many belts on my other decks and decks for friends and this one is the absolute worst to work on. Maybe its because of my age but I don't have the time to take this transport apart 3 or 4 times to get everything in alignment so it will work. I remember the good old days when manufacturers used to key parts so there was no guesswork but that costs an extra penny. My other pet peeve c-clips and plastic washers that will fly 50 feet through the air and are next to impossible to find. So the Sony may become my next paper weight, anybody else run into this problem of no line on the mode cam for the selection lever.
I just did this on a TC-K670 and it has an arrow on the mode switch.
Thanks for the write up. I couldn't figure out an easier way to do this and I had to totally disassemble the thing. Yuck. I measured the height of the LH pinch roller with a calipers so I didn't have to re-adjust it, but it was still a lot of work.
__________________
Warren

"Well, art is art, isn't it? Still, on the other hand, water is water. And east is east and west is west, and if you take cranberries and stew them like applesauce, they taste much more like prunes than rhubarb does. Now, uh... Now you tell me what you know."
  #10  
Old 04-25-2014, 12:52 PM
teknacal teknacal is offline
Serious Tapehead
 
Join Date: Nov 2013
Posts: 206
Frustrated The manual

To clarify my initial problem was the rotary encoder switch was dirty and since I had to take the transport apart to clean the encoder I also inspected the belts and they needed to be replaced. The arrow you are talking about is on the rotary encoder but the selector lever is a separate part and according to the service manual there is supposed to be a line on the cam that the pointer on the selector lever is to point to and then you have to align the rotary encoder with the arrow and the boss of the mode cam. If the selector lever is out of alignment the transport will not function properly. So my final attempt will be to find any marks at all that I can align the selector lever with but I will check the continuity on the encoder after I clean it to make sure it is working. If the encoder is shot then its time to flip the coin.
  #11  
Old 04-25-2014, 02:28 PM
draudio's Avatar
draudio draudio is offline
Serious Tapehead
 
Join Date: Mar 2014
Location: Cleveland, Ohio
Posts: 1,150
Quote:
Originally Posted by teknacal View Post
To clarify my initial problem was the rotary encoder switch was dirty and since I had to take the transport apart to clean the encoder I also inspected the belts and they needed to be replaced. The arrow you are talking about is on the rotary encoder but the selector lever is a separate part and according to the service manual there is supposed to be a line on the cam that the pointer on the selector lever is to point to and then you have to align the rotary encoder with the arrow and the boss of the mode cam. If the selector lever is out of alignment the transport will not function properly. So my final attempt will be to find any marks at all that I can align the selector lever with but I will check the continuity on the encoder after I clean it to make sure it is working. If the encoder is shot then its time to flip the coin.
As far as the cam, I can't remember if I saw a mark on it or not. I know at one point I turned the cam until the lever was at the end of the slot in the cam, and I do think I left it there. The unit is all back together and returned to service so I can't look at the mech now. I did take some pictures, as I disassembled it, but I am not sure I had a photo of the cam and sensor, I'll check tonight.
__________________
Warren

"Well, art is art, isn't it? Still, on the other hand, water is water. And east is east and west is west, and if you take cranberries and stew them like applesauce, they taste much more like prunes than rhubarb does. Now, uh... Now you tell me what you know."
  #12  
Old 04-26-2014, 12:31 PM
teknacal teknacal is offline
Serious Tapehead
 
Join Date: Nov 2013
Posts: 206
Reelstop OK DOKEY

Thanks I will give that a try, I would guess that if you are at the end of the cam travel that would be a good starting point. Now all I have to do is come up with the spare time to get the job done. I will let you know how it turns out.
  #13  
Old 04-26-2014, 05:22 PM
draudio's Avatar
draudio draudio is offline
Serious Tapehead
 
Join Date: Mar 2014
Location: Cleveland, Ohio
Posts: 1,150
I just checked my camera and apparently I deleted the pictures after finishing the job. Sorry.
__________________
Warren

"Well, art is art, isn't it? Still, on the other hand, water is water. And east is east and west is west, and if you take cranberries and stew them like applesauce, they taste much more like prunes than rhubarb does. Now, uh... Now you tell me what you know."
  #14  
Old 05-04-2014, 02:25 PM
TheSonyESFan TheSonyESFan is offline
TapeHeads.Net Member
 
Join Date: Jan 2012
Posts: 37
Cross Fingers Outside chance this may help, from WA9ES


Tecknacal-- I know the rotary switch you speak of, and have no idea if the same switch is used in my TC-WA9ES, which is a dual well deck. I'll attach the best photos I have. There is a small triangle embossed on the inside of the encoder, and a corresponding line embossed in the outer (stationary) ring. If your 707 is anything like my 9, the mode belt's replacement and the deck's reassembly, making sure none of the alignment marks is nudged, is no small feat. Making sure the selection lever stays aligned with the mode cam gear, the head assy's rear stud itself staying in the correct position, all while trying to slip the mode belt over two pulleys is not for the faint of heart. I did have a WR99ES before the (3) 9's I have now, and seem to remember there was more room to access the mode belt in that model. I was able to loosen the screws just enough to pry the case open far enough on the L/S to slip the new mode belt on w/ a dental pick. Perhaps it was beginner's luck, but everything stayed in proper alignment. Now, I do not go after the mode belt unless there is evidence of excessive wear or disintegration, or slippage while rotating the lower pulley counterclockwise, while noting any delay in the head's movement. I normally just renew the capstan belt, clean the capstans/flywheels, and replace the pinch rollers. As I only run the deck in the single side play mode, it makes replacing the mode belt usually not necessary. I hope the photos can be of some help. Good Luck, TSESF
Attached Images
File Type: jpg DSC00403.JPG (129.8 KB, 209 views)
File Type: jpg DSC00404.JPG (130.8 KB, 162 views)
File Type: jpg DSC00407.jpg (78.8 KB, 144 views)
File Type: jpg DSC00408.jpg (66.5 KB, 147 views)
  #15  
Old 05-09-2014, 11:36 AM
teknacal teknacal is offline
Serious Tapehead
 
Join Date: Nov 2013
Posts: 206
Frustrated Waiting for a part

Thanks for the pics but you do have more room than my transport does. I may also have a problem with the reel motor but I won't know until I get the parts that I ordered and the time to dig into it again. As I have 3 other decks that work great this is a back burner project. The small plastic washer that holds the idler gear in place went to outer space when I did my first test after reassembly. The reel brake did not move out of position when FF was engaged and the idler gear washer couldn't take the vibration and who knows where it went. But I have two of them on order and one extra plastic washer for the loading door just in case. This deck was always my least favorite of the 4 that I have it just didn't sound right from day one. Thanks again I will let you know how it turns out.
  #16  
Old 05-14-2014, 12:04 AM
cjacek cjacek is offline
Analogue Enthusiast
 
Join Date: Dec 2010
Location: BC, Canada
Posts: 39
hossomat: First off, amazing tutorial. Thanks so much! Can I ask you one quick question? How exactly did you remove those rec/play molex connectors from the PCB board? I'm currently working on another Sony ES deck and I need to remove those connectors but I'm afraid of damaging something if improperly done. Here's what mine look like HERE
I don't know where the latches are and if I should pinch the side and pull or what.... I don't know. Any detailed instructions will be appreciated. Thanks.
  #17  
Old 05-17-2014, 12:24 PM
hossomat's Avatar
hossomat hossomat is offline
Serious Tapehead
 
Join Date: Apr 2010
Location: Frankfurt, Germany
Posts: 105
@Cjacek:

You can just pull off those connectors. They are made to sort of snap-in on the socket (on your pic the connectors are a bit wider to the left, that's the snap-in side, so when you pull, you might pull up and a bit to the right to enable them to snap-off more easily.

But: If the socket wasn't properly soldered onto the board (e.g. with a slight gap), you might damage the connection on the board when you put the connector back into place. Happened to me before, you have to resolder the socket or maybe even bridge. That's quite rare though, so no worries. Go right ahead.
__________________
Sony Decks-Tapehead: TC-K777/777ES/777ESII, TC-K88B, TC-K700ES, 730ES, 808ES, TC-K555ESJ (ch), DTC-2000ES (ch), DTC-1000ES, CDP-R3, X55ES, CDP-502ES, CDP-701ES, DAS-702ES, TA-E + TA-P9000ES, SCD-XA777ES, BDP-S5000ES, Nakamichi Dragon, RX505, Technics SL-1210 + AT-33PTG, T+A P2000AC + 2x A3000 power amps, Infinity IRS Sigma + Kappa Center B, Renaissance 80, ELAC Dipol 60, NEC-XG852 w/ Moome-Card
  #18  
Old 05-18-2014, 06:35 PM
cjacek cjacek is offline
Analogue Enthusiast
 
Join Date: Dec 2010
Location: BC, Canada
Posts: 39
@hossomat: Thank you so much!
  #19  
Old 06-03-2014, 08:43 AM
mattuck mattuck is offline
TapeHeads Newbie
 
Join Date: Jun 2014
Posts: 3
@ hossomat: (and all others who tried doing this...)

Hi first of all thanks for this great tutorial!
I have a TCK 808ES and believe it has exactly this problem. But where do I buy the replacement belt? What is A.N.T.?

Thanks so much.
  #20  
Old 06-03-2014, 04:39 PM
cjacek cjacek is offline
Analogue Enthusiast
 
Join Date: Dec 2010
Location: BC, Canada
Posts: 39
Quote:
Originally Posted by mattuck View Post
I have a TCK 808ES and believe it has exactly this problem. But where do I buy the replacement belt?
I believe you need the Square Belt, Medium 2.5 Inch (SBM2.5). That's the "mode belt".

http://www.studiosoundelectronics.com/belts.htm#SBM

http://www.turntableneedles.com/8-TRACK--TAPE-DECK--REEL-TO-REEL_c_1771.html

Last edited by cjacek; 06-03-2014 at 04:42 PM.
Reply


Would you like to see your company or site here?  CONTACT US
For more Tapeheads affiliates and links, see the Links and Resources page.


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Sony Dual Deck Belt Replacement biddy67 Cassette 4 02-11-2017 02:48 PM
Sony TC-K670 Won't play after changing mode belt eissmann Cassette 7 07-31-2015 10:04 AM
Sony TC-K611S - Belt and Capstan Change dalgairns Cassette 4 12-05-2014 10:05 AM
Sony TC-KA6ES - Mode Belt. cragger89 Cassette 6 09-18-2013 08:37 AM
Sony TC-K850ES Mode Belt replacement, HELP captainreverb Cassette 2 09-30-2009 01:46 PM


All times are GMT -7. The time now is 11:15 AM.


Powered by vBulletin® Version 3.8.5
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.
Copyright 2018, Tapeheads.Net. All rights reserved, no use of any element incorporated into this site without express written permission.