REVOX B225 TROUBLE READING DISC - diyAudio
Go Back   Home > Forums > Source & Line > Digital Source

Digital Source Digital Players and Recorders: CD , SACD , Tape, Memory Card, etc.

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 28th June 2012, 03:45 PM   #1
diyAudio Member
 
Join Date: Mar 2011
Location: Los Angeles
Default REVOX B225 TROUBLE READING DISC

My Revox B225 has intermittent trouble reading disc's. Once a disc has stopped playing, and I go to insert a new disc it wont play it. Disc spins for a second or 2, and stops. I have to open and close tray a few times to get it to play. Once it starts to play, it will play that same disc a thousand times as long as i dont open and close the tray. There are a few moments where the opening/closing has no bearing on whether it plays or not. Not sure what it might be. rails are clean. tray closes firmly. Any help would be appreciated.
  Reply With Quote
Old 28th June 2012, 04:09 PM   #2
poynton is offline poynton  United Kingdom
diyAudio Member
 
poynton's Avatar
 
Join Date: Mar 2005
Location: A life on the ocean waves when I'm not at home in N. Wales (but I'm not Welsh so no sheep jokes!)
It sounds to me like the disk is not always sitting at the correct height relative to the laser.

Even though you say the rails etc. are clean, the first thing I would do is to strip down the mechanism and give it a thorough clean.

If you have a manual, there is a procedure for checking / setting the laser height.

Whatever you do, do not be tempted to adjust the laser controls.
The laser is working fine as they are!



.
__________________
If it ain't broke, break it !! Then fix it again. It's called DIY !
  Reply With Quote
Old 28th June 2012, 04:28 PM   #3
kevinkr is offline kevinkr  United States
diyAudio Moderator
 
kevinkr's Avatar
 
Join Date: Sep 2004
Location: Boston, Massachusetts
Blog Entries: 6
Fixed thread title
__________________
"Extraordinary claims require extraordinary evidence." - Carl Sagan
  Reply With Quote
Old 29th June 2012, 02:56 PM   #4
diyAudio Member
 
Join Date: Mar 2011
Location: Los Angeles
Quote:
Originally Posted by poynton View Post
It sounds to me like the disk is not always sitting at the correct height relative to the laser.

Even though you say the rails etc. are clean, the first thing I would do is to strip down the mechanism and give it a thorough clean.

If you have a manual, there is a procedure for checking / setting the laser height.

Whatever you do, do not be tempted to adjust the laser controls.
The laser is working fine as they are!



.
I aint touching the laser...i'm more concerned that it might be one of those blue ribbons having a kink somewhere?
  Reply With Quote
Old 29th June 2012, 04:03 PM   #5
diyAudio Member
 
PlasticIsGood's Avatar
 
Join Date: Mar 2012
Location: Bradford
Could be the tray isn't always dropping far enough to clear the edge of the disk.

If you get it working and switch off for a few minutes with the disk loaded, does it still play when restarted?

If the loader's got plastic rollers running in steel or alloy cam slots, then lubrication after cleaning is problematic. They are beginning to crack and crumble with age, and misguided greasing has in some cases hastened the process. I've used a 100% synthetic oil on the axles only but I'm still a bit worried. If your loader is clean and working and not greased, then I would leave it as it is.

There may be an adjuster for the mechanism that drops the tray.

I wouldn't adjust the spindle height until sure that the disk is seating properly and spinning freely.

Which mech is it?
  Reply With Quote
Old 30th June 2012, 03:41 AM   #6
diyAudio Member
 
Join Date: Oct 2006
The B225 uses the CDM-0 mechanism, and your your symtpom is a totally classic indication of platter motor bearing wear, which is easy to compensate for. If you remove the bottom "hatch" from under the mech, just take a #T10 Torx driver & turn the ferrite center insert you'll see practically dead center of the mech, middle bottom of the platter motor. Use the Torx driver to turn the insert clockwise, a little bit at a time, until a number of cd's have no trouble playing. You should not have to do more than 3/4 to 1 turn.

Once you have it in a spot that reliably plays every cd you try, use a bit of Duco cement or etc. along the edge of the threaded insert to lock it into place.
  Reply With Quote
Old 30th June 2012, 05:21 AM   #7
diyAudio Member
 
Join Date: Mar 2011
Location: Los Angeles
Quote:
Originally Posted by PlasticIsGood View Post
Could be the tray isn't always dropping far enough to clear the edge of the disk.

If you get it working and switch off for a few minutes with the disk loaded, does it still play when restarted?

If the loader's got plastic rollers running in steel or alloy cam slots, then lubrication after cleaning is problematic. They are beginning to crack and crumble with age, and misguided greasing has in some cases hastened the process. I've used a 100% synthetic oil on the axles only but I'm still a bit worried. If your loader is clean and working and not greased, then I would leave it as it is.

There may be an adjuster for the mechanism that drops the tray.

I wouldn't adjust the spindle height until sure that the disk is seating properly and spinning freely.

Which mech is it?
CDM-0...and yes once I get it working, if I turn it off, and back on in a day it works, its only when i open it does it go out..after a few open/close sessions it works again.
  Reply With Quote
Old 30th June 2012, 01:42 PM   #8
diyAudio Member
 
PlasticIsGood's Avatar
 
Join Date: Mar 2012
Location: Bradford
Quote:
Originally Posted by isitrisky View Post
CDM-0...and yes once I get it working, if I turn it off, and back on in a day it works, its only when i open it does it go out..after a few open/close sessions it works again.
Good. That should eliminate confusion with temperature-related problems.

If you are satisfied that the disk is seating properly and spinning freely, then checking the spindle height will probably reveal the problem. It is better to do this as per the manual, because the procedure will eliminate other possible causes before you disturb the current setting. It also should allow you to set the height so the focus motor is in the middle of its range for a flat disk playing a middle track. Then the mech will be most tolerant.

Someone with experience of your servo board might be able to tell you where the test point is. Basically you measure a voltage on the servo board that reflects the focus motor position, and adjust the screw under the spindle until the voltage is within a range specified in the manual. If it already measures correctly, then that would cast doubt on the diagnosis.

I wonder, if you can't measure and have to use trial and error instead, would it be best to use a reasonably warped disk?

With CDM1 mechs needing adjustment I remove the spindle bearing, clean it and the bottom of the spindle, and reassemble with a spot of synthetic oil on the top of the screw. Perhaps this is also possible on the CDM0 without disturbing any other settings.


The other possibility is a poor electrical connection affected by movement during loading.
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
ReVox B225 Zen Mod Digital Source 16 29th October 2010 10:51 AM
defective Revox B225 sings like a bird Bernhard Digital Source 13 9th August 2006 10:58 PM
Revox B225 Zoran Digital Source 2 15th November 2005 06:29 AM
revox b225 waltube Digital Source 0 19th February 2005 02:41 PM
Revox B225 Clock speed lancer Digital Source 4 20th October 2004 10:52 PM


New To Site? Need Help?

All times are GMT. The time now is 10:44 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2