Troubleshooting CD Players

[calavera68]

It looks like the IC is bad, nothing is loading it down.

@dr*audio Then I misunderstood, I thought that when I desoldered pin 6 and measured voltage at pin 6 if I got a reading of 5v then the IC was good and something was loading it down which is what I measured while pin desoldered. Do you know where can I buy a replacement IC?

 

[dr*audio]

@dr*audio Then I misunderstood, I thought that when I desoldered pin 6 and measured voltage at pin 6 if I got a reading of 5v then the IC was good and something was loading it down which is what I measured while pin desoldered. Do you know where can I buy a replacement IC?

I Missed that you confirmed that you desoldered it. Having said that, you measured a pretty high resistance to ground in the circuit so the IC is probably bad. Try Digikey. The part number is on the IC.

 

[Sansuiman]

Mabuchi made the better motors. The Matsushita motors are junk. I'll be curious to know which one you have.

Well, neither Mabuchi or Matsushita, but...Canon. I've never seen a Canon DC motor in this application before. In fact, I can't remember ever seeing one before in an audio product I've repaired. Looks like Canon still makes a line of mini DC motors, but I don't see a direct replacement for this series.

It appears to be a fairly high quality part, with a brass adjustable bearing set screw on the bottom (held by a dab of loctite type stuff). Going to have to pull it and see what, if anything, can be done with it. Finding a direct replacement is probably going to be tough. No idea if a substitute is feasible, assuming one with identical voltage and RPM ratings can be found. The Canon motor is an odd size (smaller body diameter and longer length than typically seen) compared to the typical DC .or from better known suppliers. It is a two wire motor, so no integral tach or other feedback, speed control is fully external. Oddly enough there is a 1/4W resistor across the motor terminals.

Anyway, I'll need to do further analysis and evaluation on this one. Strikes me as odd it won't self start, but once up to speed with an assist, will play out an entire disc (over 1 hour continuous use) perfectly with no dropouts or other problems in evidence. If it were weak (bad armature or brushes) I'd be awfully surprised if it did that well with the weight and centrifugal force of a disc spinning on it. No noise from shot bearings, either.

 

[dr*audio]

Well, neither Mabuchi or Matsushita, but...Canon. I've never seen a Canon DC motor in this application before. In fact, I can't remember ever seeing one before in an audio product I've repaired. Looks like Canon still makes a line of mini DC motors, but I don't see a direct replacement for this series.

It appears to be a fairly high quality part, with a brass adjustable bearing set screw on the bottom (held by a dab of loctite type stuff). Going to have to pull it and see what, if anything, can be done with it. Finding a direct replacement is probably going to be tough. No idea if a substitute is feasible, assuming one with identical voltage and RPM ratings can be found. The Canon motor is an odd size (smaller body diameter and longer length than typically seen) compared to the typical DC .or from better known suppliers. It is a two wire motor, so no integral tach or other feedback, you can see what the starting voltage speed control is fully external. Oddly enough there is a 1/4W resistor across the motor terminals.

Anyway, I'll need to do further analysis and evaluation on this one. Strikes me as odd it won't self start, but once up to speed with an assist, will play out an entire disc (over 1 hour continuous use) perfectly with no dropouts or other problems in evidence. If it were weak (bad armature or brushes) I'd be awfully surprised if it did that well with the weight and centrifugal force of a disc spinning on it. No noise from shot bearings, either.

My experience has been the ones with dirty commutator will work normally if given a push. If you have a variable power supply you can see what the starting voltage is. It should be around .5V. If it's over 1V it's bad. Then clean it and see if the voltage goes down.

 

[Sansuiman]

Ok, appreciate that advice. I plan to clean it, but it is a pretty well sealed unit , so trying to figure the best way to get cleaner into the motor housing. Knowing the ideal start voltage for testing pass versus fail is helpful, I wasn't aware of those figures. Not sure my variable bench supply will go that low (.5 volt) but will figure out something.

 

[calavera68]

I Missed that you confirmed that you desoldered it. Having said that, you measured a pretty high resistance to ground in the circuit so the IC is probably bad. Try Digikey. The part number is on t

I Missed that you confirmed that you desoldered it. Having said that, you measured a pretty high resistance to ground in the circuit so the IC is probably bad. Try Digikey. The part number is on the

I Missed that you confirmed that you desoldered it. Having said that, you measured a pretty high resistance to ground in the circuit so the IC is probably bad. Try Digikey. The part number is on the IC.

@dr*audio I forgot to mention that I measured the resistance from pad of pin 6 to ground while the IC pin was desoldered. Is that how I was supposed to measure the resistance or while the pin 6 was soldered back in place?

 

[dr*audio]

@dr*audio I forgot to mention that I measured the resistance from pad of pin 6 to ground while the IC pin was desoldered. Is that how I was supposed to measure the resistance or while the pin 6 was soldered back in place?

You did it correctly, I wanted to see if there was something external to the IC loading that pin down.
I don't know where I found the schematic for your player and now I can't find it on my computer or online. Can you please tell me the part number on the IC and I'll look for it or a crossreference.

 

[calavera68]

You did it correctly, I wanted to see if there was something external to the IC loading that pin down.
I don't know where I found the schematic for your player and now I can't find it on my computer or online. Can you please tell me the part number on the IC and I'll look for it or a crossreference.

The markings on the IC are as follows:

TOSHIBA 9106H
74HCU04AP JAPAN

 

[dr*audio]

The markings on the IC are as follows:

TOSHIBA 9106H
74HCU04AP JAPAN

https://www.digikey.com/en/products/detail/texas-instruments/CD74HCU04E/1508046?0=%2Fgates-and-inverters&s=N4IgjCBcoGwJxVAYygMwIYBsDOBTANCAPZQDaIALGGABxwDsIAuoQA4AuUIAyuwE4BLAHYBzEAF9CYAKwUATIhApIGHAWJkQ0uNJoxmbTpB79hYyeFkBmRctV5CJSOTlg4ABhoGQHLr0GiEoRy7nAUtmhYDhrOIPosPkYgAJJC7LgiuHxBIAC0CtBKUPwArupO5NLMFrkIhcql5ZoQTOIWBeT0FAASAMIAqu7hrUA

 

[cpt_paranoia]

That's a bog-standard HC series, unbuffered CMOS hex inverter. Often used as linear amplifiers.

 

[calavera68]

https://www.digikey.com/en/products/detail/texas-instruments/CD74HCU04E/1508046?0=%2Fgates-and-inverters&s=N4IgjCBcoGwJxVAYygMwIYBsDOBTANCAPZQDaIALGGABxwDsIAuoQA4AuUIAyuwE4BLAHYBzEAF9CYAKwUATIhApIGHAWJkQ0uNJoxmbTpB79hYyeFkBmRctV5CJSOTlg4ABhoGQHLr0GiEoRy7nAUtmhYDhrOIPosPkYgAJJC7LgiuHxBIAC0CtBKUPwArupO5NLMFrkIhcql5ZoQTOIWBeT0FAASAMIAqu7hrUA

Thank you @dr*audio I just ordered a couple. I will report back once I install the replacement.

 

[Champ]

Hello All! This time I am trying to troubleshoot a SPIDIF input issue on a Simaudio Moon I3.3 CD player.
Player is all functional except when using the input on the 3.3. Anyone have an idea of what would cause a failure in this part of the circuit. I'm not use to these micro circuits and not sure where to start. At least if I can get an idea of cause then I can talk to a local tech and not sound totally idiotic LOL.

 

[dr*audio]

Hello All! This time I am trying to troubleshoot a SPIDIF input issue on a Simaudio Moon I3.3 CD player.
Player is all functional except when using the input on the 3.3. Anyone have an idea of what would cause a failure in this part of the circuit. I'm not use to these micro circuits and not sure where to start. At least if I can get an idea of cause then I can talk to a local tech and not sound totally idiotic LOL.

Do you mean SPDIF OUTPUT? I can't see a CD player having an input. What would be the point?
Do you have an oscilloscope? You would need to probe the circuit and look at the signals.

 

[cpt_paranoia]

I can't see a CD player having an input.

Some allow the DAC to be used. I think I was looking at this company's products the other day, as someone was lauding them.

Though it looks like some confusion here: the i3.3 is an integrated amp. The mating CD3.3 is the CDP:

Simaudio Moon i3.3 Integrated Amplifier & CD3.3 CD Player (TAS 198)

“Wow, this baby’s loaded,” I muttered to myself as I scanned the back panel of the Simaudio Moon i3.3 and its sister, the CD3.3, which was idling nearby.

www.theabsolutesound.com

 

[classyharlan]

Technics SL-P777

The deck wasn't reading my test disc, so I figured the laser was going bad and so as a last resort I started fiddling with the focus/tracking pots. It turned out the deck was able to read and play other discs, but the deck is very labored in reading the TOC and starting up the first track, and the sound is distorted. The distortion improves (albeit not completely) after a CD has been playing for a couple songs, but put in another CD and the distortion is bad again. I don't know if these symptoms are due to the pot fiddling but anyway, TIA for any suggestions. (I do have a scope)

 

[dr*audio]

Technics SL-P777

The deck wasn't reading my test disc, so I figured the laser was going bad and so as a last resort I started fiddling with the focus/tracking pots. It turned out the deck was able to read and play other discs, but the deck is very labored in reading the TOC and starting up the first track, and the sound is distorted. The distortion improves (albeit not completely) after a CD has been playing for a couple songs, but put in another CD and the distortion is bad again. I don't know if these symptoms are due to the pot fiddling but anyway, TIA for any suggestions. (I do have a scope)

Well, now that you've messed with the adjustments, get the service manual and follow the procedure for making the adjustments. It's probably a waste of time because the original symptoms indicate low laser power and the laser is no longer available.

 

[classyharlan]

All the adjustments in the service manual require a servo gain adjuster which I don't have so I guess I'm SOL, but after continuous play it's exhibiting other symptoms that seem like it's not beyond hope yet...Sorry for the clutter, I wanted to delete my post before it got a reply but couldn't find a delete post button.

 

[dr*audio]

All the adjustments in the service manual require a servo gain adjuster which I don't have so I guess I'm SOL, but after continuous play it's exhibiting other symptoms that seem like it's not beyond hope yet...Sorry for the clutter, I wanted to delete my post before it got a reply but couldn't find a delete post button.

You can adjust the focus offset and tracking offset with just a scope. You adjust the focus offset for maximum amplitude and best clarity of the rf eye pattern. You can adjust tracking offset the same way or you can set the scope to DC coupled, connect to the tracking error or tracking out test point, turn the tracking gain all the way down and adjust the tracking offset so the waveform is centered about 0V. Then return the tracking error pot to mid point and also focus gain. This will be close for the focus and tracking gain. If you want to be more precise, connect the scope to the tracking error test point and set the scope to 2mS per div. Increase the tracking gain until you see it break into oscillation (you'll see a high frequency component to the waveform) then back it off until the oscillation stops, and go just a hair lower. Same thing for focus gain but use the focus error test point. You don't need that jig.

 

[dr*audio]

I have been using Liberty Electronics on e-bay as a supplier for laser pickups. Initially their offering was limited but they have expanded and now have pickups for several brands. Notable is the KSS-152A which was used on some nice players and is now available:

NEW OPTICAL LASER LENS PICKUP for ONKYO DX-1500 / DX-1700 / DX-2500 / DX-2700 | eBay

Find many great new & used options and get the best deals for NEW OPTICAL LASER LENS PICKUP for ONKYO DX-1500 / DX-1700 / DX-2500 / DX-2700 at the best online prices at eBay! Free shipping for many products!

www.ebay.com

 

[classyharlan]

Sony CDP-311

I am trying to oil the disk table motor bearing, I'm using a hypodermic-like needle to apply the oil. Below the metal plate is the motor which is flush against the plate so the needle can't get in there. Above the plate, the black plastic on which the table sits is too close to the plate for the needle to fit there either and I don't think I can find a smaller circumference needle. I don't have an angled driver to get at the motor screws to possibly drop the motor slightly so that I could get in that way but with the black plastic part holding it above I don't think I'd get enough clearance anyway. The only option I can see is to remove the table and plastic part. The service manual doesn't say how to do this removal. How is this done, or is there another option for accessing the bearing. I realize that removing the table could ruin the table height after replacement but again I don't see any other option.