ARCHIVED FORUM -- March 2012 to February 2022READ ONLY FORUM
This is the second Archived Forum which was active between 1st March 2012 and 23rd February 2022
Hello,
it is my first post on this forum and i'd like to say hi to everyone. My experience with BO started many years ago and my collection of vitage models is still growing.
One of my CD players - Beogram CD3500 - has stopped working properly. The disc is detected and starts spinning but after 2-3 secs player returns to standby.
What i have checked so far:
- C2103 replaved with proper axial Philips (47 uF instead of 33uF)- other capacitors checked with the tester are okay,- all power supplies on servo PCB are correct,- servo PCB checked for dry joints,The player turned into service mode passes first 3 steps (i.e. 1. laser arm moves correctly, 2. laser sees the disc and catches focus, 3. spindle motor works) but the problem is in stage 4 - CD stops and sometimes starts to rotate backwards for 2 secs ("4" on display remains blinking, what is assumed by service manual as the probem with radial servo).What can be the cause for such behaviour? I've changed TCA0372 as the final focus motor amplifier / radial amplifier but with no success. The only part that remained untouched and now gains my suspicion is TDA5709...
Have somebody met with similar case and would be so kind to shed some light on what to do?
I would try the TDA5709. Especially because it deals with Radial Signal Errors.
-Noah M.
RL 60.2, Beogram 5500, Beomaster 5500, Master Control Pannel 5500, Audio Terminal Remote, H9i, Beovox s45.2, Beosystem 2500 , Beogram 1602, Beolink 1000 remote, Beosound 2000, Beoremote 4.
Looking for: Beocenter 8000
Clean the laser lens. (Always first thing to try, I suppose you already did that).Check for ripple on the supply voltages. Check for cracked solder joints at the voltage regulators etc.
Martin
Thank you for your quick replies. Of course all the optics has beed cleaned, even substituted by other working CDM 4 with no results. Everything seems to point at TDA5709. Full of worry I'am looking around the chip at reasonable price and quality. Of course not from aliexpress... I've found one used within easy reach, I hope still working. We will see.
I've replaced TDA5709 - no success. I am running out of ideas what is going on
Hi,
You mention that supply voltages are OK but what about ripple as Dillen are proposing?
Have you tried to switch the Decoder board to see if that influences on the fault?
/Pindsen
Sorry about the delay, but I've just figured out what caused such behavior - a brushless spindle motor. A lower bearing is glued into its assembly with a kind of red laquer. Small flake of this mass moved under the axis and hampered it. Just after servicing this point, the player passed all 4 steps of laser alignment and works fine, nevertheless many of my CD-Rs still are not accepted by it. There is no relation with the laser diode -it is such fussy on 3 laser units tested so far. Apparently I've managed to save this player from the darkness. I wish one day it could be the same luck with my Beomaster 3500, where fault in +5V power supply propably burnt all the logic board.