Hello!
I got a 1989 CDP-M97 for free and I'm trying to get it back to life.
It looks ok regarding controls and display. The tray rubber belt had perished and a replacement got it working once again. However, the spindle motor isn't spinning at all.
The sled motor does work (I turned the assembly to displace it just about 2 cm and it reset to center position once powered on) and the laser also tries to focus. I can see the laser dot too.
The spindle motor actually turns if a 5v DC voltage is applied, so I guess this has something to do with its control. I got the service manual and it looks the TA7256P could need replacement, but on the other hand I've never serviced a CD player before so I'm not sure if the laser needs to finish some tests before telling the spindle motor to engage.
Any help/comment is appreciated.
Best regards.
JZ
I got a 1989 CDP-M97 for free and I'm trying to get it back to life.
It looks ok regarding controls and display. The tray rubber belt had perished and a replacement got it working once again. However, the spindle motor isn't spinning at all.
The sled motor does work (I turned the assembly to displace it just about 2 cm and it reset to center position once powered on) and the laser also tries to focus. I can see the laser dot too.
The spindle motor actually turns if a 5v DC voltage is applied, so I guess this has something to do with its control. I got the service manual and it looks the TA7256P could need replacement, but on the other hand I've never serviced a CD player before so I'm not sure if the laser needs to finish some tests before telling the spindle motor to engage.
Any help/comment is appreciated.
Best regards.
JZ
I doubt it's the motor, I would more suspect the Laser.
It may be Lighting, but most do.
It'll be the Prisms being dusty (nothing to be done) or the receiving Diodes (again, nothing really to be done).
Have you cleaned the Lens?
Most SONY Lasers are available as Chinese copies on ebay. The originals long since not manufactured by SONY.
Do you have an oscilloscope?
What's your skill levels?
If, and it's a real big If, you know what you're doing, you could try and turn up the Laser Emitting Diode's output. There'll be a little potentiometer on the Laser (3 if it's a KSS-240 in which case DO NOT ADJUST).
If you don't know what you're doing though, you will destroy the Laser, no ifs or buts.
And it may not be the Laser at fault. But I suspect it will be.
P.
It may be Lighting, but most do.
It'll be the Prisms being dusty (nothing to be done) or the receiving Diodes (again, nothing really to be done).
Have you cleaned the Lens?
Most SONY Lasers are available as Chinese copies on ebay. The originals long since not manufactured by SONY.
Do you have an oscilloscope?
What's your skill levels?
If, and it's a real big If, you know what you're doing, you could try and turn up the Laser Emitting Diode's output. There'll be a little potentiometer on the Laser (3 if it's a KSS-240 in which case DO NOT ADJUST).
If you don't know what you're doing though, you will destroy the Laser, no ifs or buts.
And it may not be the Laser at fault. But I suspect it will be.
P.
Hello!
Thanks for replying.
I have cleaned the lens and it does try to focus 3 times before giving up.
I do have an oscilloscope, mostly used for RF alignment of restored radios. Level would be hobbyist, lots of room to learn.
I got a replacement KSS-210A (not the original KSS-150A) and for the price point it's surely a reproduction. I'll try to swap it and get back with more details.
All the best.
JZ
Thanks for replying.
I have cleaned the lens and it does try to focus 3 times before giving up.
I do have an oscilloscope, mostly used for RF alignment of restored radios. Level would be hobbyist, lots of room to learn.
I got a replacement KSS-210A (not the original KSS-150A) and for the price point it's surely a reproduction. I'll try to swap it and get back with more details.
All the best.
JZ
Well, it was the laser alright. It's playing now!
I've been playing some CDs from start to finish without skips so far. Two questions:
1- I got the service manual and would like to optimize levels with the scope. I don't have the YEDS-18 disc nor have been able to find it online. Is there an alternative disc for this purpose?
2- I can hear the spindle motor, ever so slightly. It could be me being over sensitive as I haven't listened to CDs in ages and although this hiss does sound familiar I'd like to minimize it. Any recommendations?
Again, thanks.
JZ
I've been playing some CDs from start to finish without skips so far. Two questions:
1- I got the service manual and would like to optimize levels with the scope. I don't have the YEDS-18 disc nor have been able to find it online. Is there an alternative disc for this purpose?
2- I can hear the spindle motor, ever so slightly. It could be me being over sensitive as I haven't listened to CDs in ages and although this hiss does sound familiar I'd like to minimize it. Any recommendations?
Again, thanks.
JZ
'Hiss' could be from the focus motor coils due to the Focus Gain being set to high rather than noise from the spindle motor.
Although this is for a KSS240 the set up procedure is the same. You do not need any special discs, just pick a representative commercial disc. Try a few and reject any that have either higher or lower RF level than the average. Never use CDR/RW for alignment.
Sony CDP790 and KSS240 Restoration Project
Although this is for a KSS240 the set up procedure is the same. You do not need any special discs, just pick a representative commercial disc. Try a few and reject any that have either higher or lower RF level than the average. Never use CDR/RW for alignment.
Sony CDP790 and KSS240 Restoration Project
Sevice Manual here...........
Sony CDP-M97 Stereo Compact Disc Player Manual | HiFi Engine
Full Alignment procedure starts on page 7.
Follow them methodically and slowly, you will learn a lot and hopefully get a good working Player.
Slight noises as it plays will be normal.
Marks on the CD will also make the noises change, this is also a good learning tool, watch the RF 'Eye Pattern' as it plays a marked Disc. Slow down the Timebase on the 'Scope and you will be able to see the drop in the information.
It's amazing how much information can go missing before it skips or becomes audible.
CD is great !!!!!
Good Luck.
P.
Sony CDP-M97 Stereo Compact Disc Player Manual | HiFi Engine
Full Alignment procedure starts on page 7.
Follow them methodically and slowly, you will learn a lot and hopefully get a good working Player.
Slight noises as it plays will be normal.
Marks on the CD will also make the noises change, this is also a good learning tool, watch the RF 'Eye Pattern' as it plays a marked Disc. Slow down the Timebase on the 'Scope and you will be able to see the drop in the information.
It's amazing how much information can go missing before it skips or becomes audible.
CD is great !!!!!
Good Luck.
P.
Annnd I almost killed it.
I must have shorted +5V with ground while preparing for the adjustments. It went flat out and after some tracing it became evident that the microfuses need replacement.
The afflicted ones are definitely PS901 and PS911 (PN 1-532-675-00). Do you guys know where to find a pair?
Thanks!
JZ
I must have shorted +5V with ground while preparing for the adjustments. It went flat out and after some tracing it became evident that the microfuses need replacement.
The afflicted ones are definitely PS901 and PS911 (PN 1-532-675-00). Do you guys know where to find a pair?
Thanks!
JZ
Oh dear... be careful what you are doing.
Do you know the current rating of them? What are the numbers on them? For a lot of these you multiply the number by 40 to get the milliamp rating so a T10 would be a 400ma time delay, an F10 would be 400ma fast.
These things were common as a spares item years ago but I can't find any listed now. There are alternatives that might fit.
Wickman fuses also might fit if the leads were long enough. You could try fusible resistors as well.
Do you know the current rating of them? What are the numbers on them? For a lot of these you multiply the number by 40 to get the milliamp rating so a T10 would be a 400ma time delay, an F10 would be 400ma fast.
These things were common as a spares item years ago but I can't find any listed now. There are alternatives that might fit.
Wickman fuses also might fit if the leads were long enough. You could try fusible resistors as well.
Attachments
Yes, 1.5A
All the usual suppliers don't seem to list these anymore... we used to all them IC protectors.
I've found these by doing an image search for 'integrated circuit fuse protector'.:
Fuses: N38 - IC-PROTECTOR 1.5A... from Dönberg - UK (GBP)
All the usual suppliers don't seem to list these anymore... we used to all them IC protectors.
I've found these by doing an image search for 'integrated circuit fuse protector'.:
Fuses: N38 - IC-PROTECTOR 1.5A... from Dönberg - UK (GBP)
Attachments
I must have shorted the A.G (ground) test point with either +5V or -5V leads nearby, while placing the jumper wire.
It's breathing again, with both PS901 and PS911 replaced by N38s with same current rating. Thanks for the references.
The E-F didn't require any adjustment. Nice, symmetrical waveform at 2Vpp. The eye adjustment did yield some improvement (eye got bigger) while the "RF level" held steadily a little under 1.25V, just as required. Something however left me wondering.
From the manual, it seems the pattern should have a 0.1V DC component. Mine does have a DC component, but about 0.8V instead.
It plays flawlessly, regardless. Should anything be done about it?
Thanks.
JZ
It's breathing again, with both PS901 and PS911 replaced by N38s with same current rating. Thanks for the references.
The E-F didn't require any adjustment. Nice, symmetrical waveform at 2Vpp. The eye adjustment did yield some improvement (eye got bigger) while the "RF level" held steadily a little under 1.25V, just as required. Something however left me wondering.
From the manual, it seems the pattern should have a 0.1V DC component. Mine does have a DC component, but about 0.8V instead.
It plays flawlessly, regardless. Should anything be done about it?
Thanks.
JZ
I wouldn't worry over that either. The so called 'ground' referred to in some of the manuals for RF measurements is in fact a virtual ground (going from memory) that is really floating at 2.5V above the normal zero volt line ground. A real problem with using such a virtual ground is that the test equipment can create shorts via the probe ground leads, particularly if you have a mains grounded scope and player.
I always AC couple the scope when viewing the RF and simply use a more convenient conventional ground tbh.
I always AC couple the scope when viewing the RF and simply use a more convenient conventional ground tbh.
There's a specific RF ground test point which was used instead of the chassis ground.
Here she is in all her glory. The face plate is in mint condition, although the metal cover shows some serious wear and tear as it was the bottom element of a Hi-Fi stack. I'll probably address that later with black matte spray paint.
A big THANK YOU for all for the great insight on CDs, expertise sharing and guidance.
All the best.
JZ
Here she is in all her glory. The face plate is in mint condition, although the metal cover shows some serious wear and tear as it was the bottom element of a Hi-Fi stack. I'll probably address that later with black matte spray paint.
A big THANK YOU for all for the great insight on CDs, expertise sharing and guidance.
All the best.
JZ
I try to hook up onto this thread with my "problem" - I've recently got hold to a almost vanilla M97.
While it works really fine and is in superb condition, I recognized one problem with the error correction. After recovering from shocks, the sound changes significantly permanently, at one time it behaves like a lowpass, the other time more like a highpass. What the hell is going on in the Sony IC's?
....
AD1860 (CXD2550 configured to 18bit frame size)
replaced most of the 'lytics as well as some film caps (Philips SAL ftw!)
dedicated osc
general design not very good given the one-for-all +-5V regulator, and no RC-low-pass filter as compared to the Philips CDPs, every ICs 5V is running straight from the regulator 5V, no R, no L.
Nevertheless, a nice unit.
While it works really fine and is in superb condition, I recognized one problem with the error correction. After recovering from shocks, the sound changes significantly permanently, at one time it behaves like a lowpass, the other time more like a highpass. What the hell is going on in the Sony IC's?
....
AD1860 (CXD2550 configured to 18bit frame size)
replaced most of the 'lytics as well as some film caps (Philips SAL ftw!)
dedicated osc
general design not very good given the one-for-all +-5V regulator, and no RC-low-pass filter as compared to the Philips CDPs, every ICs 5V is running straight from the regulator 5V, no R, no L.
Nevertheless, a nice unit.
Attachments
![1618626475329[937].jpg](/community/data/attachments/860/860099-eb20aa28d6d753204d761fe00b0abc11.jpg)
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Sounds a very strange problem. Hard to say without actually hearing it for real but the first thing I would do is hook it up the audio outputs to a dual trace scope and see if anything obvious is going on. Use test discs of frequency sweeps.
Are you sure it is not something like a dry on the output sockets causing some out of phase effects as a connection goes open circuit.
Are you sure it is not something like a dry on the output sockets causing some out of phase effects as a connection goes open circuit.
Well, it was some kind of intermittant contact. Also, I noticed the remote control didn't work at times. Since I disassembled the whole unit and refitted it, the symptoms disappeared. Apart from the DACs and the XO, this was a "L" and "C" job only, Opamps and the usage of the DAC internal I/V remain. It is a fun machine compared to the Philips CDPs I'm usually into. Disassembly and testing is way more comfortable vs. Philips.
I'm still intrigued to replace the CXD2550 with something like a SM5813. Anyway, it's now out to be compared to a CDP-X505ES by a friend.
I'm still intrigued to replace the CXD2550 with something like a SM5813. Anyway, it's now out to be compared to a CDP-X505ES by a friend.
then. Intermittents are always a problem, perhaps it is worth a reflow over the whole board if it was all a bit inconclusive.Its great to hear that a generic replacement optical pickup worked perfectly.
I’ve been restoring some Sony DVD/SACD/CD players. When I need an optical pickup I search for old low-end “DVD-only” models which contain the correct optical pickup. These old DVD players can be purchased for $1-20 from garage sales, resale stores, or ebay. I haven’t tried any “aftermarket” DVD optical pickups because I can usually get an entire DVD player for less.
But for CD-onlv players which use the KSS series of optical pickups it is good to hear that the generic Chinese optical pickups are functional.
-EB
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