I'm from Argentina, I bought it at the store where I usually buy components, and seeing what happens, it's probably bad, since they had it in stock for a long time, I thought it could be good. Thank you.
Troubleshooting CD Players
- Thread starter dr*audio
- Start date
Hello, indeed, the laser is bad, I was able to test it on another machine that came in for repairs for other reasons in which the laser works. In this machine it did the same thing, the disc tries to spin but it doesn't. Thank you dr audio
Hi all
This is a really useful forum with some very knowledgeable people. I need some advice please. I picked up a Sony CDF-S400 boombox for virtually no money the other week. It seemed to play CDs fine, then would skip, mute and start hunting after two or three songs. After a short period of hunting it would give up and show "00" in the display.
Following the excellent advice from dr*audio and sources elsewhere, I did the following:
1. Found a service manual
2. Cleaned the lens
3. Oiled the spindle motor
4. Packed up the silicone buffers
5. Verified the eye diagram was open and within spec (0.85+/-0.2V)
6. Cleaned all the ribbons with Super 10 switchcleaner, also prodded them during playback to test for fatigue
7. Cleaned and relubed the sled bearings and checked the gears
8. Checked voice coils for obstructions and blew out with spray air
9. Cleaned commutator on sled motor to restore operation at low voltage
10. Probed most of the voltages on the servo control IC
11. Checked that the magnetic chuck isn't sticking
12. Verified focus and tracking error signals within normal range
13, Tried playing it at different extreme angles
And none of this has worked!
I don't think the laser is dying as when it starts skipping / hunting, the eye amplitude is maintained within tolerance but the jitter increases hugely, closing it up. There are multiple servo loops running in parallel at high speed so it seems impossible to tell which one is initiating the skip. All I can think of doing now is swapping the transport and fitting the old circuit board on the back (but the boombox transports have a different suffix, despite the mechanics looking very similar), but that feels like high risk and bad economics.
Does anyone have any suggestions please (other than the blindingly obvious one involving a skip)?
Thanks in advance...
This is a really useful forum with some very knowledgeable people. I need some advice please. I picked up a Sony CDF-S400 boombox for virtually no money the other week. It seemed to play CDs fine, then would skip, mute and start hunting after two or three songs. After a short period of hunting it would give up and show "00" in the display.
Following the excellent advice from dr*audio and sources elsewhere, I did the following:
1. Found a service manual
2. Cleaned the lens
3. Oiled the spindle motor
4. Packed up the silicone buffers
5. Verified the eye diagram was open and within spec (0.85+/-0.2V)
6. Cleaned all the ribbons with Super 10 switchcleaner, also prodded them during playback to test for fatigue
7. Cleaned and relubed the sled bearings and checked the gears
8. Checked voice coils for obstructions and blew out with spray air
9. Cleaned commutator on sled motor to restore operation at low voltage
10. Probed most of the voltages on the servo control IC
11. Checked that the magnetic chuck isn't sticking
12. Verified focus and tracking error signals within normal range
13, Tried playing it at different extreme angles
And none of this has worked!
I don't think the laser is dying as when it starts skipping / hunting, the eye amplitude is maintained within tolerance but the jitter increases hugely, closing it up. There are multiple servo loops running in parallel at high speed so it seems impossible to tell which one is initiating the skip. All I can think of doing now is swapping the transport and fitting the old circuit board on the back (but the boombox transports have a different suffix, despite the mechanics looking very similar), but that feels like high risk and bad economics.
Does anyone have any suggestions please (other than the blindingly obvious one involving a skip)?
Thanks in advance...
dr*audio
Fish fingers and custard!
The RF signal should be 1.2V P-P to 1.5V P-P. Your laser is kaput.
Hi dr*audio
Thanks for coming back. The service manual for the unit states on two separate pages that the RF output should be 0.85Vp-p +/- 0.2V, but I don't disagree with your diagnosis, as the eye Vp-p seems to drop slightly over a period of minutes to the bottom end of the tolerance range, although it seems to stabilise at this point. It's really annoying that they don't put laser bias current test points on these things. Anyway, I will take a chance on an ebay pickup as I haven't spent much except time so far.
Thanks again
G
dr*audio
Fish fingers and custard!
Liberty Electronics on ebay is the only reliable source I have found.
Hi dr*audio et al.
I thought I'd report back on the CD player problems. I played around with some freezer spray and found that this would restore reliable playback for a few minutes, which definitely supported the diode end-of-life assertion. After a false start with a KSS-213C I bought the right diode (KSS-213R) from the only source available (AliExpress!). It cost me 4x what I paid for the player, but still not very much. I'm delighted to report that it played its first CD all the way through once fitted. I'm sure the eye is more sharply defined, although I note it's still coming in within the 0.85 +/- 0.2 V pp manufacturer's spec. I guess this is just an unusual player in that respect.
Anyway, thanks very much for the help,
G
I thought I'd report back on the CD player problems. I played around with some freezer spray and found that this would restore reliable playback for a few minutes, which definitely supported the diode end-of-life assertion. After a false start with a KSS-213C I bought the right diode (KSS-213R) from the only source available (AliExpress!). It cost me 4x what I paid for the player, but still not very much. I'm delighted to report that it played its first CD all the way through once fitted. I'm sure the eye is more sharply defined, although I note it's still coming in within the 0.85 +/- 0.2 V pp manufacturer's spec. I guess this is just an unusual player in that respect.
Anyway, thanks very much for the help,
G
dr*audio
Fish fingers and custard!
I have been buying KSS213 pickups from BD Enterprises and they always work. They are going out of business, though. Liberty Electronics on Ebay is another good supplier. I suspect you got a defective part with the KSS213C. The suffix is not supposed to make a difference. Would you care to share the supplier's name on AliExpress?
Hi dr*audio
Well, I was willing to give the KSS-213C a go as it looked very similar (although there was more metalwork round the diode) and I could get it cheaply and quickly. The problem was that it didn't fit mechanically in the CFD-S400L transport. The rack pitch was visibly too big and the notch on the other side (where it slides against the metal frame of the transport) was too shallow. The circuit board with the pot was also too big. I couldn't fettle it because the tracks on the PCB were too close to the edge. So I didn't even get round to removing the solder blob!
FWIW, I also considered buying a complete new generic transport but the entire control / DAC PCB was fixed to the back of the existing one via the motor through-holes and I didn't want to take the chance that the new one didn't line up.
KMX Tech was the supplier of the KSS-213R.
I think this particular player is an unusual one (just my luck!) as it doesn't accept the generic laser head; that might also be why its eye voltage is lower than usual. I didn't record the part number of the transport and can't really face taking it apart again. Anyway, it's a success story for now!
G
Well, I was willing to give the KSS-213C a go as it looked very similar (although there was more metalwork round the diode) and I could get it cheaply and quickly. The problem was that it didn't fit mechanically in the CFD-S400L transport. The rack pitch was visibly too big and the notch on the other side (where it slides against the metal frame of the transport) was too shallow. The circuit board with the pot was also too big. I couldn't fettle it because the tracks on the PCB were too close to the edge. So I didn't even get round to removing the solder blob!
FWIW, I also considered buying a complete new generic transport but the entire control / DAC PCB was fixed to the back of the existing one via the motor through-holes and I didn't want to take the chance that the new one didn't line up.
KMX Tech was the supplier of the KSS-213R.
I think this particular player is an unusual one (just my luck!) as it doesn't accept the generic laser head; that might also be why its eye voltage is lower than usual. I didn't record the part number of the transport and can't really face taking it apart again. Anyway, it's a success story for now!
G
Hi @dr*audio , got another one for you.
I have a Sony CDP-C365 5-disc changer, and I am getting a slight distortion, particularly on louder tracks, in the left channel. It's most notable on hi-hats and cymbals, which are very distorted, and less-so on vocals and snare drums. If I listen with headphones though, the overall distortion is much more obvious than with speakers.
Any ideas as to some things to narrow down?
Thank you!
I have a Sony CDP-C365 5-disc changer, and I am getting a slight distortion, particularly on louder tracks, in the left channel. It's most notable on hi-hats and cymbals, which are very distorted, and less-so on vocals and snare drums. If I listen with headphones though, the overall distortion is much more obvious than with speakers.
Any ideas as to some things to narrow down?
Thank you!
dr*audio
Fish fingers and custard!
You will need an oscilloscope and a test CD with sine waves on it to troubleshoot this. Distortion on only one channel is probably going to be either IC103 (digital filter / D-A converter) which is unlikely to be available, or the output IC 501, which is probably also not available. There is a slight possibility it could be a bad solder joint on the output jack. Look for a circular crack in the solder.
If the solder joints are ok, play the test CD and probe the inputs and outputs of IC501 to see where the distortion comes in.
Jazzguy54
New Member
My Carver SD/360-A is suddenly not recognizing discs, any and all discs including factory CDs. If I try to play a disc, it rotates to the proper position, pauses for a few seconds, goes on to the next slot or disc, pauses for a few seconds and the goes on to the next...etc, without actually playing any discs. It's like it doesn't recognize there is a disc there or is unable to play them for some reason. Is there a possible simple fix to this problem that I could try or is it something more serious?
Bradbrews
Super Member
My Technics SL-P222 will play CDRW’s fine for about 4 or 5 discs and then will only read commercial CD’s.
The unit has only ever had the lens cover cleaned off, otherwise it’s factory.
If I then turn it off the next day it will play a CDRW again. Just turning it off and back on again doesn’t help.
Laser? Power Supply?
The unit has only ever had the lens cover cleaned off, otherwise it’s factory.
If I then turn it off the next day it will play a CDRW again. Just turning it off and back on again doesn’t help.
Laser? Power Supply?
dr*audio
Fish fingers and custard!
Sounds like the laser power is low and dropping as it warms up. The only way to know for sure is to look at the rf waveform on a scope.
Bradbrews
Super Member
Thanks- that’s what I was afraid of.
It seems laser replacement is harder-given part availability- and more costly than most other hifi issues.
The Technics has a nice informative display, that so many more modern units lack, as well as digital output.
dr*audio
Fish fingers and custard!
This player uses a Philips CDM4 CDM unit, with the laser and disc motor as an assembly. I saw it being offered on Aliexpress for $46 but I don't know that I would trust the seller. They don't have any way to look at feedback for prior sales. If you do buy one, it is imperative that you replace the unit at an antistatic work station, with an antistatic mat and an antistatic wrist strap, and keep the shorting clip on the flex cable until you connect it in the unit. They are very easily damaged by ESD.
cpt_paranoia
Addicted Member
Dutch Classics list says it's a Technics SOAD70A laser assy. That's a linear motion unit, so easy to distinguish from the CDM4 swing arm.
You really mean CD-R, right? I would not expect any CD player to play a CD-RW.
