Hi, my CD104 has developed an issue recently whereby, after being in use for maybe 45 mins to an hour, if I try and play a new disc it wont spin-up and read the disc and the red error light just comes on. If I power it off and then try again a few hours later it will usually be back to normal.
Also, though not sure if this is linked, I am noticing an occasional small skip or slight dropout in the sound.
After doing some reading I decided the 'griplets' were a likely candidate and so reworked all, by desoldering, opening the holes up a little so they would accept some wire through the boards and then solderering back up. I also checked all the 22uf caps on the decoder board, found one that had a highish ESR reading and so decided to replace all (13) of these, even though the others all measured well. Don't actually think I checked any of the other caps except for those on the power pcb, which were all fine. Was expecting that this work would made have a difference (given how troublesome I hear the griplets can be), but no change. Well, at least the griplets are now done!
So, any ideas where to look next? Open back up and test every cap, or could this be maybe the pre-amp/laser pcb issue that the following article mentions
~ Classic CD Player Modification & Modernisation ~
Thanks for any pointers.
Also, though not sure if this is linked, I am noticing an occasional small skip or slight dropout in the sound.
After doing some reading I decided the 'griplets' were a likely candidate and so reworked all, by desoldering, opening the holes up a little so they would accept some wire through the boards and then solderering back up. I also checked all the 22uf caps on the decoder board, found one that had a highish ESR reading and so decided to replace all (13) of these, even though the others all measured well. Don't actually think I checked any of the other caps except for those on the power pcb, which were all fine. Was expecting that this work would made have a difference (given how troublesome I hear the griplets can be), but no change. Well, at least the griplets are now done!
So, any ideas where to look next? Open back up and test every cap, or could this be maybe the pre-amp/laser pcb issue that the following article mentions
~ Classic CD Player Modification & Modernisation ~
Thanks for any pointers.
Okay, not sure why I tried this, but just decided to give the tray a little helping nudge just as it was almost fully closed and it span up and read the TOC (and plays fine). The thing is the drawer is closing properly by itself (new belt and regreased), but the 'jolt' seems to have made it spin-up again....though I suspect a temporary fix. I guess there must be a switch that senses when the drawer is closed? Maybe I need to look for that and clean it?
Update: nudging the drawer shut did not help the next time this happened. What did work was powering off then rotating the turntable a little with my little finger through the top of the tray assembly, then when powered back on the disc spun-up, TOC appeared it could play. Does this suggest what the possible fault might be?
There may be a problem with the spindle motor or its associated PCBs.
As featured in your link: ~ Classic CD Player Modification & Modernisation ~
As featured in your link: ~ Classic CD Player Modification & Modernisation ~
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Hello,
It is obvious that this is a problem associated with the temperature, (at 45 minutes it fails, and it goes off again) or there is some component with a cold solder on the pcb, or some voltage regulator (transistor) fails when heats up.
My recommendation is a visual inspection of the pcb in search of cold solders, if you do not find any, let the equipment fail, and at that moment in the voltage regulators apply a little cold spray, when the problem is solved, you will have located the problem, do not waste time with the capacitors ... the problem is a solder or a semiconductor (no resistor, no capacitor, no coil,no transformer).
You will find the problem with a spray of frozen and 45 minutes.
is a semiconductor, look for a semiconductor, sure
A voltage regulator ...
regards
It is obvious that this is a problem associated with the temperature, (at 45 minutes it fails, and it goes off again) or there is some component with a cold solder on the pcb, or some voltage regulator (transistor) fails when heats up.
My recommendation is a visual inspection of the pcb in search of cold solders, if you do not find any, let the equipment fail, and at that moment in the voltage regulators apply a little cold spray, when the problem is solved, you will have located the problem, do not waste time with the capacitors ... the problem is a solder or a semiconductor (no resistor, no capacitor, no coil,no transformer).
You will find the problem with a spray of frozen and 45 minutes.
is a semiconductor, look for a semiconductor, sure
A voltage regulator ...
regards
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Update: I opened her up again and did some cleaning/reflowing on pcb's I had not looked at before, also dismantled and then reinstalled the servo/laser PCB and motor and then set turntable height. Then, just as I was about to call it a day, I decided to check laser voltage (which I had intended to leave alone) and found it reading around 1100 mv. The pot was turned almost fully anti-clockwise. I reduced this to match the specified range (pot pretty central) and now the operation issues seem to have gone. I assume laser voltage was the key issue here.
What I did notice though was that when setting the voltage it varied between CD's and so I ended up taking readings from several and setting the pot so that with most CD's I was seeing c.530 mv, but the range was from c.480 to c.650 mv. Not sure if this is normal or whether this points to another issue. But, for now, the CDP is operating nicely.
What I did notice though was that when setting the voltage it varied between CD's and so I ended up taking readings from several and setting the pot so that with most CD's I was seeing c.530 mv, but the range was from c.480 to c.650 mv. Not sure if this is normal or whether this points to another issue. But, for now, the CDP is operating nicely.
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