Philips CD104 tweaks - Page 78 - 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 9th October 2012, 02:37 AM   #771
diyAudio Member
 
PlasticIsGood's Avatar
 
Join Date: Mar 2012
Location: Bradford
Just done a total 'lytic re-cap and de-griplet. Was tetchy now seems perfect.

Ripples in the frequency response are quite shocking. I can see why Mission changed the filter.

Is it normal for the disc to continue spinning indefinitely after loading if no buttons are pressed?
  Reply With Quote
Old 10th October 2012, 09:40 AM   #772
simonov is offline simonov  Bulgaria
diyAudio Member
 
simonov's Avatar
 
Join Date: Aug 2005
Location: PZ
I think it should stop spinning after reading the CD info. Does the player actually work and play music?
  Reply With Quote
Old 10th October 2012, 02:40 PM   #773
diyAudio Member
 
PlasticIsGood's Avatar
 
Join Date: Mar 2012
Location: Bradford
Quote:
Originally Posted by simonov View Post
I think it should stop spinning after reading the CD info. Does the player actually work and play music?
It works perfectly in every respect. It stops spinning at end of play, if stop is pressed, and it used to stop if it failed to read the TOC. Now it never fails to read the TOC.

Having read the TOC after loading using the open/close button, it keeps spinning whilst displaying the number of tracks and total time. If I press stop it stops, and the display reverts to two dots.

If it's a fault, I can't think how it can happen
  Reply With Quote
Old 11th October 2012, 04:43 PM   #774
simonov is offline simonov  Bulgaria
diyAudio Member
 
simonov's Avatar
 
Join Date: Aug 2005
Location: PZ
Well it's a rather interesting "issue". I have to dig out my old 104. Anyways if it works don't try "fixing" it. Just enjoy the play
  Reply With Quote
Old 21st February 2013, 02:46 AM   #775
diyAudio Member
 
Join Date: Dec 2008
Default weird play behavior also

Just started scanning this old thread because I picked up a CD 104 cheap recently...it had a drawer that didn't close all the way that I managed to fix with a little cleaning, re-lube of the load mech and some automotive belt treatment on the belt.

It does the same thing when I load a disc...goes into "autoplay" mode every time...playback starts and all it shows on the display screen is total play time. However, If I push stop and then restart it or select a track with the skip button it will display the track and time elapsed for that track.

Other than that the player seems to work fine. Its no collectors item, hell its scratched up, has a small pinch/tear on the ribbon cable to the radial arm/laser and smelled like a dirty ashtray when I took it out of its box...I almost didn't want ti to work...amazingly it did!!!...and the sound is smooth as silk

I hope it keeps working long enough for me to have some fun modifying it
  Reply With Quote
Old 21st February 2013, 06:14 AM   #776
jives11 is offline jives11  Europe
diyAudio Member
 
jives11's Avatar
 
Join Date: Mar 2004
Location: Hampshire
Havn't been in here for a while as I have been more active over at vinylengine . Re-gripleting should be your first port of call, it fixes no end of apparently unrelated problems. Mine would only read the TOC when warmed up for about 30 minutes. Replacing (important - not just a resolder) the rivets with wire links, soldered on both sides fixed this and it plays from cold.
  Reply With Quote
Old 12th May 2013, 04:23 PM   #777
chartz is offline chartz  France
diyAudio Member
 
Join Date: Jul 2009
Location: Burgundy
Hello,

I got a CD 104 which doesn't work.
Usually I get lucky just fixing the griplets, but not this time.
The players makes two attempts at reading the CD, and then it stops and displays 0000.
New caps, all voltages fine. The laser focus works, but its arm will always remain close to the turntable, and releases itself only when power is turned off. I checked many many values and they are all correct. The scope showed nothing conclusive either.
Any ideas please?
Thanks.
  Reply With Quote
Old 12th May 2013, 09:44 PM   #778
diyAudio Member
 
PlasticIsGood's Avatar
 
Join Date: Mar 2012
Location: Bradford
AFAIK only two wires go to the radial motor, from the servo board. One of these (-) is grounded on the servo board via a 1R5 current-sensing resisistor, and the other (+) is driven positive or negative by a complementary pair of transistors.

So, check the voltages on those two wires. One or both must be wrong.

Without knowing quite how the servo circuit works, I see two possible causes of error. First, if the radial motor coil is shorted to ground near or at its (-) end, then the motor would still work but the servo will have lost its current sensing. Easy to check by disconnecting the radial motor and measuring its resistance, and the resistance between each end of the coil and ground. Do you know what the coil resistance should be?

Second, assuming the radial motor is OK, there must be a fault in the servo circuit. In that case you need to check back through the circuit to see where the offending voltage is coming from. My manual isn't very clear, but there seems to be very little guidance on what the voltages should be around there. The voltages to the bases of the two transistors should be + and - 11.5V and their emitters should be at the levels of the +1 and -1 supplies. There are a few test points around the uA741 and HEF4053, and a few more dotted around the places the HEF gets its input from.

I could be completely barking up the wrong tree...I don't even know how these mechs find their way to the "home" position. Unlike linear carriages, they don't have a limit switch.
  Reply With Quote
Old 13th May 2013, 06:59 AM   #779
chartz is offline chartz  France
diyAudio Member
 
Join Date: Jul 2009
Location: Burgundy
Thanks.
Trouble is, the manual doesn't say anything about how the coil (tested good) is fed by the servo. So there is voltage alright, it changes a bit when I press play, but the radial motor keeps the carriage stuck to the turntable.
Does anyone know how voltage changes during the complete travel of the swing arm?
  Reply With Quote
Old 13th May 2013, 11:41 AM   #780
chartz is offline chartz  France
diyAudio Member
 
Join Date: Jul 2009
Location: Burgundy
Service loop test A passes.
Service loop test B passes first stage (repeat beacon on) then it never manages to read the CD.
  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
Philips CD104 Bob Roberts Digital Source 14 24th September 2004 03:25 PM


New To Site? Need Help?

All times are GMT. The time now is 10:23 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