Troubleshooting CD Players

[dr*audio]

Pin 1 to ground -4.92v
Pin 2 to ground .2952v
Pin 1 to Pin 2 -5.237v

Ok, it's definitely trying to drive the sled motor. If you move the sled motor manually so the laser is in the center of it's travel, does the sled move? If not, you've got a bad motor or a broken wire going to the motor.

 

[urbom]

Nope, sled never moves. Focus clicks only happen when I manually put the sled to the inside. If I put 5v to the motor from my bench supply, it runs, and I checked continuity on the wires all good there, i may search for a bad solder joint….

 

[dr*audio]

Nope, sled never moves. Focus clicks only happen when I manually put the sled to the inside. If I put 5v to the motor from my bench supply, it runs, and I checked continuity on the wires all good there, i may search for a bad solder joint….

Bad solder joint or bad crimp.

 

[beels]

Hi,
Thanks to Dr*Audio and other contributors for this excellent information repository!

I'm working on my Sony CDP-C89ES. This unit uses the KSS-240A pickup.
It was skipping occasionally, though much worse towards the later tracks of the CD.

I removed the laser platform, cleaned the slide, oiled the spindle motor, and oiled the laser motor.

Problem 1 (spindle motor and laser behavior)
---------
After reinstalling the laser platform, the player is now behaving oddly.
When I power on, the laser always moves to the far outside position, clamps, lens bobs up (sometimes), then ...nothing. Spindle motor never moves. After a few seconds, the carousel moves to the next position and repeats the prior steps.

I applied 6V to both the laser and spindle motors (in circuit) and both motors spin freely and quietly in both directions (with reverse voltage).

I have checked both ribbon cables multiple times.


Problem 2 (intermittent power up):
---------
This one is strange and intermittent: Sometimes the player is unresponsive to Power On. If I simply flip the whole chassis upside down, and then invert it back to normal position, the player will power up.

I searched and searched the circuit board and connections on the underside of the unit to ensure nothing is shorting on the copper bottom plate. Everything looks normal.

I did some more playing with this Sony 89ES.

Prob 1: I manually cranked the laser assembly in about 25% by rotating the gear train, and when I powered up, the pickup traveled to the home position. So it is still capable of moving sometimes.
Then I cycled through the carousel several times with a mix of empty slots and CDs. In each case, the laser platform rises up and the CD is clamped (if one is in that position), spindle never moves, and it just sits with the Play button illuminated. Then I select the next disk, same thing.
Remember, before I started messing with this player, the spindle always moved normally, and the laser always behaved normally - except for some skipping.

Prob 2: Rather than intermittent power up, it's probably more accurate to say intermittent front panel lights. There are other indications of power always present, such as the variable headphone output LED is always lit. I can restore front panel lights, either by momentarily inverting the whole chassis or sometimes, by just unplugging mains for a few seconds then replugging.

 

[j!m]

I’d be looking at the front panel for bad solder joints and/or caulking connections.

 

[beels]

I’d be looking at the front panel for bad solder joints and/or caulking connections.

Thank you. I have done this but not found anything yet. I've been primarily focused on getting the pickup working (Prob. 1).
I've also wondered if some failure in the laser platform area could be causing the intermittent front panel issue.

 

[j!m]

Go for the low hanging fruit. Since it “fixes” itself when inverted I suspect a poor connection. Pull the face apart and check everything at 10x.

 

[dr*audio]

I did some more playing with this Sony 89ES.

Prob 1: I manually cranked the laser assembly in about 25% by rotating the gear train, and when I powered up, the pickup traveled to the home position. So it is still capable of moving sometimes.
Then I cycled through the carousel several times with a mix of empty slots and CDs. In each case, the laser platform rises up and the CD is clamped (if one is in that position), spindle never moves, and it just sits with the Play button illuminated. Then I select the next disk, same thing.
Remember, before I started messing with this player, the spindle always moved normally, and the laser always behaved normally - except for some skipping.

Prob 2: Rather than intermittent power up, it's probably more accurate to say intermittent front panel lights. There are other indications of power always present, such as the variable headphone output LED is always lit. I can restore front panel lights, either by momentarily inverting the whole chassis or sometimes, by just unplugging mains for a few seconds then replugging.

1. When it attempts to play a CD, do you see the laser lens moving up and down? (Focus Search?) If it's not doing focus search, the home switch is probably damaged or dirty. If it does focus search but never starts spinning, the laser is either bad or the disc motor is bad. Do you hear a sizzling sound? If you manually turn the CD a little, will it try to spin? If so, the disc motor is bad.

 

[beels]

1. When it attempts to play a CD, do you see the laser lens moving up and down? (Focus Search?) If it's not doing focus search, the home switch is probably damaged or dirty. If it does focus search but never starts spinning, the laser is either bad or the disc motor is bad. Do you hear a sizzling sound? If you manually turn the CD a little, will it try to spin? If so, the disc motor is bad.

Thanks for the response, doc.
No, the lens doesn't bob anymore. I've seen it bob recently, but not for the past few days. So it appears no attempt at focus search currently.
I applied 5V directly to both the spindle motor and laser motor contacts (with motors still in circuit) and both spin smoothly and quietly in either direction. No sizzling. No, the motor will not try to spin the CD with manual assist.

There was no concern with either of the motors or the laser focus previously. So I have created this problem with my repair attempts.
I inspected the leaf switch near the home location and don't see anything out of the ordinary. I couldn't tell how to take it apart. Maybe I got some lube inside or something.
I was a little sloppy with my ESD precautions. Could an ESD-zapped pickup assembly act like this?

 

[beels]

Go for the low hanging fruit. Since it “fixes” itself when inverted I suspect a poor connection. Pull the face apart and check everything at 10x.

(Sony 89ES)
It's possible my #2 power issue is related to a ground strap on the main board not making proper contact to the bottom chassis. I can't get it to fail at the moment to verify.

 

[dr*audio]

(Sony 89ES)
It's possible my #2 power issue is related to a ground strap on the main board not making proper contact to the bottom chassis. I can't get it to fail at the moment to verify.

It isn't starting focus search. The first thing you should do is check all the power supply voltages, particularly 7V and 5V. Sony uses those damn IC protectors that look like a black plastic transistors but have 2 leads. I bet you blew one.
If the supplies are ok, check S101 the limit switch to make sure it really closes when the pickup is in the home position.

 

[beels]

Hmmm. I looked all over the underside of the main board and the sled board. I don't see a single component that looks like a black plastic 2-legged transistor. I do see a small group of normal looking 3-legged transistors on the opposite side of the main board. Do the IC protectors look like through-hole transistors or SMD transistors? Would I find them on the main board or the sled board?

It's not clear to me where I should test for the 5V and 7V. Can you please direct me?

 

[urbom]

Bad solder joint or bad crimp.

Okay Dr. I was measuring the wrong pins on p103.
The real answer is:
Pin 1 to ground 0v
Pin 2 to ground 0v
Pin 3 to ground .29v
Pin 4 to ground -5.26v

 

[dr*audio]

Okay Dr. I was measuring the wrong pins on p103.
The real answer is:
Pin 1 to ground 0v
Pin 2 to ground 0v
Pin 3 to ground .29v
Pin 4 to ground -5.26v

Measure the voltages on all pins of Q106 when you insert a CD and push play.

 

[urbom]

Measure the voltages on all pins of Q106 when you insert a CD and push play.

Pin 1 13.79v
Pin2 0.46v
Pin 3 0.904v
Pin 4 0
Pin 5 -12.739v
Pin 6 0.013v
Pin 7 0.317v
Pin 8 0.101v
Checked several times

 

[dr*audio]

Pin 1 13.79v
Pin2 0.46v
Pin 3 0.904v
Pin 4 0
Pin 5 -12.739v
Pin 6 0.013v
Pin 7 0.317v
Pin 8 0.101v
Checked several times

Put a Cd in and measure the voltage on Q104 pin 20. Before you said it was 5V or something. But it goes to pin 4 on Q106 and now you measure 0V. If it measures 0V, check Q104 Pin 22 voltage. If it's anything but 0V and the sled is not in the home position, Pin 20 should read some voltage to move the sled. If not, Q104 is probably bad.

 

[urbom]

Put a Cd in and measure the voltage on Q104 pin 20. Before you said it was 5V or something. But it goes to pin 4 on Q106 and now you measure 0V. If it measures 0V, check Q104 Pin 22 voltage. If it's anything but 0V and the sled is not in the home position, Pin 20 should read some voltage to move the sled. If not, Q104 is probably bad.

Q104 pin 20 4.206v
Q106 pin 4 0 v
Q104 pin 22 0v
Sled not home

 

[dr*audio]

Q104 pin 20 4.206v
Q106 pin 4 0 v
Q104 pin 22 0v
Sled not home

Q104 pin 20 connects to Q106 pin 4 through a resistor that you could not find. Pull the board and follow the trace.
Q104 pin 22 reads 0V so the player thinks the home switch is closed, so in that case the sled would not move. With the power off, measure the resistance between Q104 pin 22 and ground. If it's a short, investigate why the home switch is closed.

 

[beels]

Hmmm. I looked all over the underside of the main board and the sled board. I don't see a single component that looks like a black plastic 2-legged transistor. I do see a small group of normal looking 3-legged transistors on the opposite side of the main board. Do the IC protectors look like through-hole transistors or SMD transistors? Would I find them on the main board or the sled board?

It's not clear to me where I should test for the 5V and 7V. Can you please direct me?

[Sony 89ES] I'm still not sure where to check the voltages. I do have some additional behavior observations though: When I manually wheel the sled to the home position and power up, the laser lens pops up and the sled travels to the outermost position. Lens stays popped up until I cut power. Whether the sled starts from the home position, halfway, or anywhere else, it always travels to the outside with the lens popped up.

Does this still sound like a blown IC protector, or does it point back more to the limit switch? I inspected that as best I could through the plastic cover. I'll need to take the upper deck off the assembly to get a closer look. Having trouble with the 4 tiny screws. They look like they might be PZ0 posidrive screws. They are in there tight.

 

[dr*audio]

[Sony 89ES] I'm still not sure where to check the voltages. I do have some additional behavior observations though: When I manually wheel the sled to the home position and power up, the laser lens pops up and the sled travels to the outermost position. Lens stays popped up until I cut power. Whether the sled starts from the home position, halfway, or anywhere else, it always travels to the outside with the lens popped up.

Does this still sound like a blown IC protector, or does it point back more to the limit switch? I inspected that as best I could through the plastic cover. I'll need to take the upper deck off the assembly to get a closer look. Having trouble with the 4 tiny screws. They look like they might be PZ0 posidrive screws. They are in there tight.

IC203 pin 3 7V
IC202 Pin 12 5V
Look on the schematic at the power supply section and test all the voltages.