Philips Test Sample CD's - 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 13th April 2008, 10:54 AM   #1
diyAudio Member
 
Join Date: Feb 2006
Location: UK
Default Philips Test Sample CD's

Hi,

I'm trying to restore an old 1985 B&O Beogram CD50 CD Player.

The Service manual calls for 'Philips Test CD without Defects' or 'Sony YEDS5'

I can get access to Philips CD 3 or 5A, would either of these be any good?

Cheers,
Ben
  Reply With Quote
Old 13th April 2008, 04:56 PM   #2
Mooly is offline Mooly  United Kingdom
diyAudio Moderator
 
Mooly's Avatar
 
Join Date: Sep 2007
Any good disc is fine. You don't need any special discs for normal service work/alignment. Is there a particular problem with the unit, what pickup does it use ?
Regards Karl
  Reply With Quote
Old 13th April 2008, 08:34 PM   #3
diyAudio Member
 
Join Date: Feb 2006
Location: UK
I went ahead and ordered the test sample 3 and 5 anyway. I found out that the disc 3 is the 'disc without defects' that the service manual calls for.

As far as the pickup, I havent got a clue!
I've found out that it uses a 3 beam laser system and the disk gets loaded upside down. Apparently its of Japanese origin, maybe Aiwa?

The problem was just a spindle motor in need of a little lube, but someone previously had messed with the pots on the servo PCB, so the machine isn't happy reading discs.

I can snap a pic of the guts if you think knowing the pickup type will help.

Thanks,
Ben
  Reply With Quote
Old 14th April 2008, 06:48 AM   #4
Mooly is offline Mooly  United Kingdom
diyAudio Moderator
 
Mooly's Avatar
 
Join Date: Sep 2007
Hi Ben, Do you have an oscilloscope, it's the only way to adjust/check any player. You have to be able to "see" the signal coming off the disc to correctly set up. You say someone has twiddled the pot's, that could be a problem and I think you need access to the service manual. Depending on the machine there may be adjustments for focus and tracking gain, EF balance and PLL lock. As a generalisation you can try this. If it will play at all, if you turn the focus gain up you may hear "white noise" coming from the optical pickup itself, adjust up to the point that the noise is apparant and then back off slightly. Tracking gain set initially to around mid point. EF balance is very critical, you certainly need scope for this. Try moving slightly each way and see if playability improves. PLL or phase locked loop again very critical, you need the set up procedure to adjust correctly and a frequency counter. You can set it to the midway between the points at which the player "loses it" assuming it is a pot for this adjustment (sometimes a coil, if it is don't touch). If you have a 'scope you may be suprised to see that the RF signal or eye patern coming off the disc always looks the same, it does not matter what the content of the disc is, the only exception is the "gap" between tracks tracks. Good luck
Regards Karl
  Reply With Quote
Old 15th April 2008, 06:57 AM   #5
diyAudio Member
 
Join Date: Feb 2006
Location: UK
Hi,

Yes, I have an oscilloscope and the service manual. I think I also need a signal generator for setting up the spindle motor amplifier, but hopefully I can use my PC for that.

The Player does still play CD's, albeit with clicks and pops in the sound sometimes, and its slow to read the TOC and skip between tracks.

Maybe someone can shed some light onto the origin of the pickup.


Cheers,
Ben.
Attached Images
File Type: jpg dsc00064.jpg (96.3 KB, 432 views)
  Reply With Quote
Old 15th April 2008, 07:06 AM   #6
Mooly is offline Mooly  United Kingdom
diyAudio Moderator
 
Mooly's Avatar
 
Join Date: Sep 2007
You have cleaned the lens have'nt you. You need to put scope on the R.F. signal first to check it's quality and amplitude.
  Reply With Quote
Old 15th April 2008, 07:08 AM   #7
Mooly is offline Mooly  United Kingdom
diyAudio Moderator
 
Mooly's Avatar
 
Join Date: Sep 2007
What does that label say on the pickup, cant read it
  Reply With Quote
Old 15th April 2008, 07:12 AM   #8
diyAudio Member
 
Join Date: Feb 2006
Location: UK
Hi,

Yes the lens has been cleaned. I can actually hear the white noise you mentioned when I play discs.

The label reads:

87-046-283-01
V301R02A04Q0

Cheers,
Ben
  Reply With Quote
Old 15th April 2008, 07:16 AM   #9
Mooly is offline Mooly  United Kingdom
diyAudio Moderator
 
Mooly's Avatar
 
Join Date: Sep 2007
Not familiar with that particular unit. First things first, A clean lens, and put scope on the RF signal. This tells all. Does the manual give an amplitude for this signal, usually about 1.2 volts PEAK TO PEAK on scope. Is the "diamond" shape clear when you expand the timebase on the scope.
  Reply With Quote
Old 15th April 2008, 07:20 AM   #10
Mooly is offline Mooly  United Kingdom
diyAudio Moderator
 
Mooly's Avatar
 
Join Date: Sep 2007
Is there a set up procedure in the manual for EF balance, this is critical adjustment. Needing a signal generator to set up the spindle motor implies a hall effect type motor. Dont think this is problem really, once playing the motor should not loose lock.
  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
Some sample graphs, some big differences loninappleton Full Range 17 9th August 2008 11:15 PM
sample policy abuse mirlo Parts 1 19th December 2006 05:41 AM
DSO Bandwidth vs sample rate bzo Parts 3 23rd February 2004 03:53 PM
free sample MaXiZ Everything Else 13 18th January 2004 10:33 PM
Sample rates Prune Digital Source 9 18th September 2003 07:24 PM


New To Site? Need Help?

All times are GMT. The time now is 04:57 AM.


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