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Troubleshooting CD Players

It’s a handy “go-to” for a shot from the hip for an in dash unit. Especially if you’re up against a major disassembly to get it out.

But I’ve run it on thrift store funds before testing at the store.
 
I've never had a CD player yet that a cleaning disc actually worked on. Have had a few that benefitted from detailed hand cleaning of the lens with a swab (using a minimal amount of 91% isopropyl, not enough to have it puddle on the lens or surrounding areas).

YMMV, bit all a disc with those little brushes will do is remove loose dust from the lens, which could be done as well by canned air. More often than not, there is film/haze on the lens surface that will require more than the cleaning disc is capable of.
 
You are correct but the only way to do that with a slot loader is to remove the unit from the dash and disassemble it. That labor cost could exceed the value of the vehicle…
 
@j!m, true enough, unless one is comfortable doing it oneself. I am, but certainly recognize many aren't. I've done cleaning and repairs on some Alpine HU's I own as well. I presently have two CD-A7894 head units from 2001 still working beautifully, along with their original 6 disc trunk mount changers. Also have a similar CD-A9833 from about 2004 still in service. These are all in cars form the late 80's to early 90's, and I keep them because they do what I want, and look period correct in their respective applications.
 
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Here's another thing to look for when repairing CD players.
I was working on a NAD 512 that had been sitting in my closet of junk for 10 years. It needed a Sony CXA1082BQ, which at the time was hard to find and expensive. Now I have a good source for them cheap, so I ordered the part and got it working, BUT, it would intermittently drop out, like it had bit errors. I suspected the sled motor so I monitored the sled motor drive with a scope. It would slowly go up to 0.7V and then the sled would move, but when it dropped out the voltage would go much higher. Aha, I said, bad sled motor. I removed the drive gear and checked to make sure the laser was sliding freely and it was. Removed the sled motor and compared it with a new one, driving it with a bench supply to see what the lowest voltage it would start at. Both motors were the same, about 0.25V. Ok, I figured maybe it has a bad spot and sometimes won't start, so I replaced it. Same problem. So I moved the gear, turning it slowly to see if it hung up, and it did. Removed the gear that drives the rack gear on the laser and it had a bunch of teeth gouged out! I have a few brand new mechanisms I bought when they were available (actually they still are; Liberty Electronics has them) so I pulled a gear off one and installed it in the player. All fixed. I checked the limit switch to make sure it is working, because that could cause the gear to get ground up, but the switch is fine. So, be sure to check the gears!
 
Good advice by @dr*audio there. Many of the gears used are nylon or similar soft plastics. Many of these age poorly, and can be easily broken if something jams, or gets "out of sync" by a tooth or two, especially where they overshoot the limit of their intended travel. Hardened lubricating grease can also be a contributing factor.

I've also had gears with hairline cracks because they "swelled" with age, and since the shaft they spin on is metal, the gear had to split to accommodate the suddenly smaller inside diameter creating mechanical stress. Sometimes replacement can be found on eBay, if the player is a popular model. Others have to be reinforced somehow for repair.
 
Got a strange problem with my Sony CDP-C260Z. It appears to be "sunsetting" where it works well for a couple hours, but then it starts having trouble reading discs especially the tracks closer to the outer edge of the disc. The audio starts getting super choppy and "fizzly." Eventually it won't even read the TOC. Mostly on CDR's though. It's only from 1997, so I don't think its failing capacitors. If I just use it for like one or two CDR's a day, its fine, but anything more than that, and it starts to fall flat on its face.
 
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Trance88 said:
Got a strange problem with my Sony CDP-C260Z. It appears to be "sunsetting" where it works well for a couple hours, but then it starts having trouble reading discs especially the tracks closer to the outer edge of the disc. The audio starts getting super choppy and "fizzly." Eventually it won't even read the TOC. Mostly on CDR's though. It's only from 1997, so I don't think its failing capacitors. If I just use it for like one or two CDR's a day, its fine, but anything more than that, and it starts to fall flat on its face.
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Looks like the laser is failing. It uses a KSS-213. The suffix letter doesn't matter. Liberty Electronics on E-bay has good ones.
 
Caps are certainly suspect at nearly 30 years... Not saying they are bad, and I have stuff from the 70's still performing, but it is something to consider at this point.
 
Revox H2 CD player will not spin up. I have been trying all the usual spots for schematics or service manual and cannot find anything. Does anyone have any service documentation on this particular model? I know that it uses the Philips CDM4/27 laser but not much else. Any guidance is greatly appreciated.
 
rockrink said:
Revox H2 CD player will not spin up. I have been trying all the usual spots for schematics or service manual and cannot find anything. Does anyone have any service documentation on this particular model? I know that it uses the Philips CDM4/27 laser but not much else. Any guidance is greatly appreciated.
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Most likely the laser is bad. No longer available, but Revox has been really good with parts in the past so maybe they still have the CDM unit.
 
dr*audio said:
Most likely the laser is bad. No longer available, but Revox has been really good with parts in the past so maybe they still have the CDM unit.
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Dr. isn't it a bit hasty to condemn the laser unit prior to checking the freedom of the slide(s) and possibly the limit switches?
 
There's always a chance the laser is bad, but having serviced many players now, I've found quite a few other failures; stuck slides, stuck gears (often old grease all hardened up), weak/bad spindle motors, bad capacitors in the servo section, etc. anyone doing routine work on CD players (or planning to) should really get a laser power meter to verify if a laser is good, or failing, as it is far too easy to just blame the laser.
 
Sansuiman said:
There's always a chance the laser is bad, but having serviced many players now, I've found quite a few other failures; stuck slides, stuck gears (often old grease all hardened up), weak/bad spindle motors, bad capacitors in the servo section, etc. anyone doing routine work on CD players (or planning to) should really get a laser power meter to verify if a laser is good, or failing, as it is far too easy to just blame the laser.
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It's a swing arm laser so no slides or gears, and even if it is the disc motor you can't get a replacement for a Philips mechanism, you have to replace the entire CDM assembly. Also based on my experience with Philips based players with CDM type mechs, it's always the CDM unit. Some people say it's the caps but I have never seen that. Replace the CDM unit and it works, so it couldn't be anything else.
 
@dr*audio, fair enough, as regards the Philips pickups, though neccessity is the mother of invention. I'd expend a fair amount of effort and ingenuity to graft in a new spindle motor on a really nice player. I know that "officially" these pickup assemblies were not intended to be serviceable at component level, but that wouldn't stop me from trying.

Is the saving of one of these players worth such extraordinary efforts invested? Not on paper, nor by any logic, certainly. Then again, the prices currently being paid for many "vintage" players can hardly be justified, yet some still command significant money on the secondary market. But of course sentimentality, and a desire to preserve some of the better older examples of this tech drive some of us to do things that cannot be justified solely on a cost to "payoff" basis.

The Vintage Audio Laser web site has posted some remarkable repairs and restorations. I'm not aware of anyone else operating at that level (and aspire to be able to do such exceptional work myself), but the proprietor of that site has successfully replaced and calibrated the laser diode in TAOHS-L pickups, has created a replacement for a failed PLL circuit module used in several notable Technics models, and has gone to great lengths to preserve many of the most sought after first and second generation players, to great success. Point being that many erstwhile write-offs can be saved, given the funding, advanced technical expertise, and determination to do so. Admittedly, most people won't pull off saves like that, but they are possible.
 
Sansuiman said:
@dr*audio, fair enough, as regards the Philips pickups, though neccessity is the mother of invention. I'd expend a fair amount of effort and ingenuity to graft in a new spindle motor on a really nice player. I know that "officially" these pickup assemblies were not intended to be serviceable at component level, but that wouldn't stop me from trying.

Is the saving of one of these players worth such extraordinary efforts invested? Not on paper, nor by any logic, certainly. Then again, the prices currently being paid for many "vintage" players can hardly be justified, yet some still command significant money on the secondary market. But of course sentimentality, and a desire to preserve some of the better older examples of this tech drive some of us to do things that cannot be justified solely on a cost to "payoff" basis.

The Vintage Audio Laser web site has posted some remarkable repairs and restorations. I'm not aware of anyone else operating at that level (and aspire to be able to do such exceptional work myself), but the proprietor of that site has successfully replaced and calibrated the laser diode in TAOHS-L pickups, has created a replacement for a failed PLL circuit module used in several notable Technics models, and has gone to great lengths to preserve many of the most sought after first and second generation players, to great success. Point being that many erstwhile write-offs can be saved, given the funding, advanced technical expertise, and determination to do so. Admittedly, most people won't pull off saves like that, but they are possible.
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I think I tried to replace one of those spindle motors and the disc table is bonded onto the shaft and I could not get it off.
Regarding a laser power meter, they are difficult to get a good reading with because the lens is going up and down doing focus search, and it only lasts a few seconds. You can usually use a scope to look at the focus error signal. If there is none or it is very low, the laser is bad. Likewise, on a player using a Sony chipset you can look at FOK and see if it gets focus lock. If not, and if there is not Focus Error signal, the laser is probably bad. Rarely the amp IC or the Servo IC is bad. Again, you can determine that with a scope, no need for a laser power meter. We had one at work and I found it unreliable.
 
dr*audio said:
It's a swing arm laser and it's outside of it's life expectancy at this point.
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Dr. if the limit switches are gunked up bad enough will the unit think a disc isn't loaded, causing the spindle motor to stay idle? Have you ever run into that issue?
 
dr*audio said:
Moderator, please make this a sticky. I am tired of repeating this info in multiple posts so I want to make a memory dump in one place.
1. CD won't play:
Observe the mechanism with no disc loaded and the cover off (don't look directly at the lens!) When the player starts, the first thing the micro does is make sure the drawer is loaded and the mechanism has risen up to the play position. Then it will reverse the sled motor until the home position switch closes, then it moves the pickup forward a bit until the switch opens. (If the pickup doesn't move at all, the CD mechanism may not be in the fully loaded position, or there may be a problem with the sled drive or motor. Check the loading belts.) There is a switch that tells the micro that the pickup is in the home position so it can stop the motor and keep the pickup from jamming. If the switch gets dirty the micro keeps the motor on in reverse and the pickup won't move. With no CD in the player, turn the player on and watch the laser pickup (don't look directly at the lens!) If the pickup moves toward the disc motor then moves back, the switch is ok. If the pickup moves toward the disc motor and doesn't move back, the switch is dirty and doesn't close. On Sony based players, the home switch is a leaf switch located on the board that the disc motor is on. There is a plastic cover on the end of the leaf switch. Note what position it is installed in, and gently pull the cover off. Then clean the contacts by drawing 600 grit sandpaper through them just a couple of times. Then flush the debris out with contact cleaner or alcohol and gently replace the plastic cover. Depending on the construction of the mechanism, you may have to remove the disc motor board in order to get to the switch.
After the player correctly senses the home postion, the focus search starts and the laser pickup lens moves up and down. If the lens doesn't move after the pickup finds home, either the pickup is bad or the cable for the pickup is broken, or the drive IC is bad, or there is a power supply problem. Some players have IC protectors that look like transistors with only 2 leads. They go open.
If focus search starts, load a CD. If the disc spins, focus search was successful and the player achieved focus lock. The pickup may be good. If the table of contents is displayed but the player doesn't play, the pickup is either bad or the internal adjustments must be performed. A scope is necessary for this. If you have a scope and can see the RF waveform, it should be 1.2V - 1.5V peak to peak, on a player with a Sony chipset and many others as well. Use a commercially recorded CD, preferably an older issue, because newer issues can have lower reflectivity. If the RF waveform is lower than 1V peak to peak, the pickup is probably bad. Do the adjustments and if the waveform doesn't improve, the pickup is bad. Panasonic / Technics players have lower amplitude on the RF waveform, I think it's 1V peak to peak. Not sure about Philips players, I think they are 1.2 - 1.5V.
If the CD doesn't spin, the pickup could be bad or the disk motor, or disc motor drive could be bad. If the player does focus search and the disc doesn't spin and you hear a sizzling sound, the disk motor is bad. Try giving it a turn with your finger, it may start turning. If you replace the disc motor, the disk table height is critical. Measure the height before you replace the motor. You can use a ruler or calipers or feeler gauges. A good trick is to find something, a piece of wood cut to the same dimension, a nut, several feeler gauges; that fits under the disk table and you can use that as a gig to remount the disk table on the new motor, shoving the table down until it hits your gauge. The disk table must be glued to the motor shaft with a drop of superglue.

2. Skipping CDs:
There are several causes of skipping CDs. The most common is the top bearing of the disk motor is dried up and a couple of drops of light weight machine oil will cure it.
The second most common cause of skipping is the suspension of the CD mechanism is sagging and the CD chuck that holds the CD in place is rubbing on the arm that supports the chuck. This is cured by stretching the springs on the mechanism by the length of one turn. You must be sure to return each spring to the same position on the mechanism, because they are different tensions to account for the weight of the motors. If the player uses rubber bumpers instead of springs you can either replace them, replace them with springs if you can find some, or install washers under the bumpers to bolster them up.
On Sony 5 disc players that are sensitive to vibrations, open the top and insert a CD. Observe the chucking arm and magnetic chuck. On some Sony players the plastic chassis warps over time and the magnet is no longer centered in the chucking arm and rubs against the inside edge of the hole it rides in. If it appears not to be centered, push on the arm, from the front, sides and back to determine which edge the chuck is scraping on. You will be able to hear it scrape. If it does, remove the chucking arm. There is a screw in the back of the arm that adjusts the height of the arm and secures it, along with a spring. Remove the chuck from the arm by twisting the 2 halves until the plastic tabs line up with the openings. Now that the chuck is free, file or cut the hole in the arm on the side that it rubs, to enlarge the hole by about 1/8". Don't overdo it or the chuck will fall through.
Remove all burrs and plastic shavings and re-assemble the chuck and install the arm in the player. Adjust the height of the arm so that the chuck floats in the arm with equal parts above and below the arm. The improper height of the arm is another cause of skipping.
If the chuck is not off center, is it riding too low in the arm and scraping on the arm? If so, adjust the height of the arm if it is adjustable on this model.
Sometimes the machined posts that the laser slides on need to be cleaned and re-lubricated, especially if the owner had pets. Clean them thoroughly with alcohol and then apply 2 drops of light weight machine oil to each post on either side of the laser.
Clean the lens. Use a Q tip moistened with ethanol (NOT Isopropyl alcohol, it can cloud plastic!), distilled water or Kodak Lens Cleaner.

3. Drawer won't open / stay closed:
Replace the loading belts.

This covers most of the problems found in CD players.
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Audiokarma rules!
Lubed the spindle motor of a Sharp DX-R770 and no more last track skips

Motor made the same general noises as an underlubed Thorens turntable motor accepting new lube.
 
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