Troubleshooting CD Players

[joejoe19849]

In portable players the suspension starts to sag over time and the CD rubs against the inside of the case. If it has springs you can carefully stretch them but must just have rubber bellows. You can try putting washers under the bellows.

Thanks for your reply. I will have to check it out but it didnt sound like the cd was rubbing with friction. Last night i did notice that if i tilt the back of the player up to about a 45 degree angle it stopped the skipping. What would cause that?

 

[dr*audio]

Thanks for your reply. I will have to check it out but it didnt sound like the cd was rubbing with friction. Last night i did notice that if i tilt the back of the player up to about a 45 degree angle it stopped the skipping. What would cause that?

Same thing or a weak sled motor. Listen for a ticking sound as the disc spins. Also look at the cheap plastic disc table that the CD snaps into and see if any of the plastic tabs are broken or any of the 3 ball bearings missing.

 

[joejoe19849]

Same thing or a weak sled motor. Listen for a ticking sound as the disc spins. Also look at the cheap plastic disc table that the CD snaps into and see if any of the plastic tabs are broken or any of the 3 ball bearings missing.

Ok so i tried putting washers under the rubber bellows. That did not work. It doesnt seem to be the suspension that is the issue. The cd doesn't seem to be rubbing against the player. I checked to see if the disc table had any of the 3 ball bearings missing. It did not. I do notice that when you push the button on the disk table to eject a cd, sometimes it sticks a little so you have to make sure you press it with enough force. Dont know if that is an issue but just wanted to mention it. So is the only other possibility the sled motor. Is that easy to change out? Ive never done that before. Where would i even find one for this player? Sorry for all the questions, this is just frustrating.

 

[dr*audio]

You will probably not be able to buy a new motor. There are very few mechanical parts available for CD players anymore.

 

[joejoe19849]

You will probably not be able to buy a new motor. There are very few mechanical parts available for CD players anymore.

Thats too bad. I will probably just get a replacement used player on ebay. Do you recommend a specific brand or model for a portable player that is good quality and doesn't cost much? Thanks

 

[Pio1980]

The motors may be a readibly available oem catalogue item.

 

[Binkman]

This member can use some help.. http://audiokarma.org/forums/index.php?threads/magnavox-cdb-500-tray-wont-stay-open.786234/

 

[joejoe19849]

I have a portable cd player that has quite a bit of white noise/static coming out of the headphone jack when playing a cd. If you press pause the noise goes away but once you hit play it returns. The player does not seem to have the static when i use it through the line out to speakers though. Any idea what is wrong with the headphone jack? By the way i have tried several headphones so i know that they are not the issue. Thanks

 

[N8Nagel]

I had a similar issue with my Sansui receiver (2000A) eventually I left it on overnight and the noise then became apparent in speakers as well. Headphones are more sensitive than speakers when it comes to things like this apparently.

 

[patrick_l]

Few days ago I have discovered something very interesting about troubleshooting CD-players. I have finally decided to try to repair JVC XL-V174 CD-player. Most of the discs wouldn't spin at all, and only few would spin little bit, but there were no TOC. It couldn't read any disc.
First thing I tried was obvious, cleaned lens, but without any result. Then I thought, maybe some of the leaf switches may be bad, so I checked them and all tested ok. Used DMM for testing. Then I tried to play a little bit with few pots, for regulating focus, tracking etc, and i made sure to bring it back to initial position if it doesn't make any difference. That didn't help at all. I have service manual, and in that moment I thought that I would need to make series of measurement of corresponding ICs, and I was like 'I will do that on some other occassion', and then I looked to the laser, and saw that there is one potentiometer more. I assumed it has something to do with laser power, and I knew if i mess with that it is big possibility that I destroy laser if I bring it's current above some point. So I moved that potentiometer, almost unnoticeable. Tried to put disc, and voila, disc was read almost in second!
I tried another dozen of discs and everything seemed to be perfect! And then problem again, discs would spin but not read, so I tried to move potentiometer again back and forth, and again it was back in business, for a 15 minutes. Again problem, wont read discs. So I treated that potentiometer with Wuerth Multi Spray (something like DeOxit), and moved potentiometer back and forth for about 50 times, and now it is perfect device in every way. It even read CD-R without any problems.
So it is possible that potentiometer near the laser get oxidized over time, and when I figured that out, my CD-player was back in business, even thou I got it for free when I bought one amplifier a couple of years ago. Now I'm happy that CD-player wouldn't had read discs in that time, otherwise I wouldn't get it for free .

Also another observation I noticed few times, when I suspect that laser is bad. Beside fact disc wouldn't spin at all, below laser, when you pull out transport, on the opposite side there is a something like a sensor, I'm not sure how it is called, some kind of array. When there is dark dot in the middle of that array, for sure laser is not ok! Another symptom is that focus circuit appear to move lens up and down but with abnormal speed!

I hope this facts may help somebody.

 

[Jake Gloudy]

Hi there...
I've got a Mitsubishi DP-112 that I'm having some issues with.. so far nothing I've seen here has quite matched my issue so I figured I'd see if I could get some advice. When I load a disc, it starts spinning clockwise and the laser moves from the inside of the disc towards the outside. When the laser reaches the outside of the disc, the spinning stops briefly, then reverses direction (now spinning counterclockwise) and the laser moves back towards the center of the disc. The disc gradually comes to a halt and nothing happens from there. On the display there is simply the letter 'E' indicating an error of some sort. Any idea what the problem could be?

 

[dr*audio]

Hi there...
I've got a Mitsubishi DP-112 that I'm having some issues with.. so far nothing I've seen here has quite matched my issue so I figured I'd see if I could get some advice. When I load a disc, it starts spinning clockwise and the laser moves from the inside of the disc towards the outside. When the laser reaches the outside of the disc, the spinning stops briefly, then reverses direction (now spinning counterclockwise) and the laser moves back towards the center of the disc. The disc gradually comes to a halt and nothing happens from there. On the display there is simply the letter 'E' indicating an error of some sort. Any idea what the problem could be?

The CD spinning in reverse direction means the spin is too fast and braking is applied by means of reverse voltage. This can be for various reasons but is usually because it can't read the disc. If you put a CD in and push drawer close button, does it display the table of contents? If not the laser is probably bad.

 

[Jake Gloudy]

No, it does not display the table of contents.. is it likely that I can find a replacement laser if that is indeed the problem?

 

[patrick_l]

Onkyo CR-L5 have problem. Read any disc without problems, plays half of tracks of every cd without any error, but last tracks on cd fail to read. For example, if CD have 16 tracks, and I want to hear number 16 first, it won't read it. But if I press play, number 1 start really fast and I could reach that number 16 with search button, by advancing one by one, or directly via remote, jump from any number to 16. Leaving CD to play, will play every single track without issues. But directly entering number via remote, or chose on device before play results in canceling operation (after some time, and I hear laser is struggling to read).
Also strangely, if I press 15, and then play, I hear laser trying to get to that point on CD, and while it's struggling, when I hit next, it will read 16 very quick!
What did I do? Cleaned laser lens, and dismantled everything applying new grease, but it didn't help, so I think it's not about gummed grease. I didn't notice anything strange on plastic gears, nothing broken there.

 

[dr*audio]

Try lubricating the disc motor. Apply a couple drops of light machine oil to the base of the shaft with a syringe.
Do not use grease on the posts that the laser slides on. Clean them with alcohol and use a few drops of oil on them.

 

[dr*audio]

No, it does not display the table of contents.. is it likely that I can find a replacement laser if that is indeed the problem?

No.

 

[patrick_l]

Try lubricating the disc motor. Apply a couple drops of light machine oil to the base of the shaft with a syringe.
Do not use grease on the posts that the laser slides on. Clean them with alcohol and use a few drops of oil on them.

Thank you for advice. Pity I didn't have chance to try that, because buyer didn't complain about problem I mentioned to him. It was not a big deal for him, options I explained as problematic ones.
But for sure I will know in the future what to do.

 

[Johnny_Law]

Thanks for all this great info @dr*audio - I have a TEAC PD-D2500 5-disc changer that won't start playing discs ~50% of the time. Everything mechanically works I believe as intended (carousel rotates, slides in/out fine; disc clamp and rotational motor with associated belts work properly and are in good shape; laser moves both up and down vertically and in and out radially when I hit play without a CD loaded).

On the occasion that it won't start playing, it will clamp the CD and spin it while the laser goes through its motions. The TOC won't be displayed. It will eventually unclamp the disc and not confirm there is a disc in that position in the carousel. I can keep hitting play and eventually it will play the disc. This leads me to believe, from earlier posts, that the laser is going bad?

On the occasion that it does start playing, it will play through all songs properly (other than the occasional skip which it seems sensitive to do).

Thanks,
Ryan

 

[dr*audio]

Thanks for all this great info @dr*audio - I have a TEAC PD-D2500 5-disc changer that won't start playing discs ~50% of the time. Everything mechanically works I believe as intended (carousel rotates, slides in/out fine; disc clamp and rotational motor with associated belts work properly and are in good shape; laser moves both up and down vertically and in and out radially when I hit play without a CD loaded).

On the occasion that it won't start playing, it will clamp the CD and spin it while the laser goes through its motions. The TOC won't be displayed. It will eventually unclamp the disc and not confirm there is a disc in that position in the carousel. I can keep hitting play and eventually it will play the disc. This leads me to believe, from earlier posts, that the laser is going bad?

On the occasion that it does start playing, it will play through all songs properly (other than the occasional skip which it seems sensitive to do).

Thanks,
Ryan

It is either the laser going bad or the cable going to the laser is going intermittent. If you have an oscilloscope you can check the rf signal and that will tell you if the laser is going bad. On most players the rf signal should be 1.25 - 1.5V peak to peak. If it is 1V or below the laser power is low. You can adjust it back up with the pot on the laser assembly and it could work for a week or for a year. Sometimes you get lucky.

 

[Johnny_Law]

It is either the laser going bad or the cable going to the laser is going intermittent. If you have an oscilloscope you can check the rf signal and that will tell you if the laser is going bad. On most players the rf signal should be 1.25 - 1.5V peak to peak. If it is 1V or below the laser power is low. You can adjust it back up with the pot on the laser assembly and it could work for a week or for a year. Sometimes you get lucky.

Thank you! Unfortunately I don't have an oscilloscope - although I want one!

Last night I did some more we'll say 'scientific' testing and found that the problem seems to be CD-specific. I tried playing 5 different CDs 20 times in each of the 5 disc spots in the carousel (100 times total each). 3 of the 5 played 100% of the time, 1 of the 5 played 99% of the time, and 1 of the 5 played ~50% of the time. There was no significant correlation between carousel position and success rate. The 1 out of 100 times that disc #4 didn't play, the CD seemed to be spinning FAR too fast, and when the clamp disengaged it was spinning so fast that it skidded to a stop after it landed back down on the carousel. The disc that only played half the time, #2, is really scratched on the bottom. Of the 50 or so times it didn't play, a handful of those times it also spun way too fast and skidded to a stop.

I'll try more CDs and see if I can find a correlation between not starting and anything about the CD (e.g., scratches, age). Would love your thoughts on why it might spin a disc too fast, not recognize it, and disengage the clamp while it's still spinning pretty fast.