The player: CD473 - This has been modified - seperate DA board, clock module and a Ben Duncan output stage. This player has never been used much, I transfered all the bits from my old CD473 which had performed great for over 15 years, the only 'new' bit is the clock module - bought off fleebay.
The problem: Plays fine when cold, but after 30 minutes or so it starts playing up - can't read the disc and an 'Err' message comes up. Switch it off for 10 minutes - everything fine again. Unfortunately I did not think to check the player before installing the clock, but that is my suspicion. I am running the clock from a seperate transformer, as are the DA board and the output module, but everything there checks out.
There seems to be conflicting advice on the net about installing clock modules, they all tell you to remove the two capacitors near the crystal, then some say to remove the resistor in parallel, some say leave it in. I left it in, otherwise it would leave a pin on the chip floating. Is this right?
Anyone any ideas?
Thanks.
The problem: Plays fine when cold, but after 30 minutes or so it starts playing up - can't read the disc and an 'Err' message comes up. Switch it off for 10 minutes - everything fine again. Unfortunately I did not think to check the player before installing the clock, but that is my suspicion. I am running the clock from a seperate transformer, as are the DA board and the output module, but everything there checks out.
There seems to be conflicting advice on the net about installing clock modules, they all tell you to remove the two capacitors near the crystal, then some say to remove the resistor in parallel, some say leave it in. I left it in, otherwise it would leave a pin on the chip floating. Is this right?
Anyone any ideas?
Thanks.
This does not sound like a clock problem.
I assume you have checked for dry / bad solder joints.
To me, this sounds more like a power supply problem, probably a capacitor going bad.
Look for bulging / leaking caps in the power section.
Andy
I assume you have checked for dry / bad solder joints.
To me, this sounds more like a power supply problem, probably a capacitor going bad.
Look for bulging / leaking caps in the power section.
Andy
Thanks Andy
that is what I thought - but I have replaced all the electrolytics on the board.
It will be playing fine, then I press stop, replay, error. leave for 10 minutes, fine. It is fine once it starts playing, just when you stop it, it will not read again - would overheating do this?
that is what I thought - but I have replaced all the electrolytics on the board.
It will be playing fine, then I press stop, replay, error. leave for 10 minutes, fine. It is fine once it starts playing, just when you stop it, it will not read again - would overheating do this?
I've got the same problem in a 473 I got awhile back, would sure like it to work. Don't have service manual nor am I an expert, where would I look for power supply on this unit. Unit has 1 large board and a smaller elevated board. Thanks for any suggestions.
Mike
Mike
The problem is infuriating. The player sometimes reads the disc, sometimes does not, sometimes plays, sometimes does not. If it gives an 'err' reading, keep pressing play about 10 times and it works, searches fine, skips tracks fine, then when you stop and press play again, the problem happens again.
The skip beckons.
The skip beckons.
there may be problem with mains. have you checked the noise on voltage lines with scope? especially negative power supply. as i remember the -6V goes through additional transistor controlled by 7912 and stabilitron reference. Although check grounding.
If it is a heat related issue, then a can of freezer spray will help you find the problem.
my experience with this set..... once this error happen... stop(stop play, set still on) the set, open the cover... move(touch) the lens up and down... and it can play for a few disc without problem.... So I thought the problem is something to do with the "spring" force of the focus lens connection (since it is such an old set......) Also see some discussion in the web that CDM 4/11 (CDM2) is less reliable as compare to CDM 4/19...
Have you checked the non electrolytic capacitors? The freezer spray will find any heat related problems like dry joints or component problems. I have previously reheated every solder joint on a board after a visual inspection found no faults and a similar problem went away. It took a long time but it worked. check all the connections and cables the cd laser cables move back and forth all the time maybe it has a fault internally on the cable? Which would explain moving the lens fixing the problem.
- Status
- Not open for further replies.