Hi All,
I'm looking at a Philips CD-880.
Full Re-Cap done.
Tried a 'new'-er Laser Pen from a Marantz CD-65MKII, 'fault' remains.
Fault is;
From cold, some discs, not all, the Player takes a long time to read their TOC. Once read, Track 1 playing is instant. If Opened and Closed, long time TOC read again !
Once Player warm, TOC read instant.
Full Re-Cap done. All PSU Rails lovely and clean. Eye Pattern nice and clean and does not differ in 'fault' condition from when working.
I'm stumped so far.............any ideas welcome.
P.
I'm looking at a Philips CD-880.
Full Re-Cap done.
Tried a 'new'-er Laser Pen from a Marantz CD-65MKII, 'fault' remains.
Fault is;
From cold, some discs, not all, the Player takes a long time to read their TOC. Once read, Track 1 playing is instant. If Opened and Closed, long time TOC read again !
Once Player warm, TOC read instant.
Full Re-Cap done. All PSU Rails lovely and clean. Eye Pattern nice and clean and does not differ in 'fault' condition from when working.
I'm stumped so far.............any ideas welcome.
P.
Faults like that can be difficult.
Could there be any issue with the platter motor ? It might also be worth trying sparing use of freezer spray if the fault seems heat related.
Laser diode driver transistors can do odd things on Philips players. If it was dropping out at a microsecond level when cold, could it affect the TOC reading ?
You've done all the first line stuff... whatever it is, is going to be something out of the ordinary. PLL adjustments (if there are any) within pull-in range when cold ?
Could there be any issue with the platter motor ? It might also be worth trying sparing use of freezer spray if the fault seems heat related.
Laser diode driver transistors can do odd things on Philips players. If it was dropping out at a microsecond level when cold, could it affect the TOC reading ?
You've done all the first line stuff... whatever it is, is going to be something out of the ordinary. PLL adjustments (if there are any) within pull-in range when cold ?
I have wondered about this. There is no 'height adjustment' on the CDM1 MKII so cannot change this but then that would cause the Eye Pattern to be 'out of focus' so not that (?). I did at one point think it may be a little 'stiff' (not spinning as freely as I remember these did) but when I took it all apart, the Platter cannot be removed as the Magnets for the Motor are attached to this. Also without the Motor fitted it seemed to free up so just the pull of the Magnets making me think it was stiff (?). I did wonder about removing the Laser Pen (again !) and bathing the chassis in oil (?).
I'm not sure there's any adjustments for this but it's something I've not checked so will do so, thanks for the reminder.
P.
If the problem is dick-related, what would the variables be... and affected resultant
- disks vary in reflectivity (a lot - I measured RF signal amplitude difference of 0.3 - 0.4 V PP)
- thickness (focus servo); you already mentioned there's nothing that could be done...?
- let’s assume that the position of TOC is at the same radial distance on all discs, so this would not be a variable, right?
- disc weight; check if the spindle servo can easily compensate for a little of additional ‘stress‘ that you can apply by placing your finger on a disc while it’s playing… If the servo does not correct, the spindle motor may need a good wash in isopropyl alcohol. The commutators get shorted from a long use and a lot of graphite deposits, resulting in a reduced torque capability. Washing the inside of the motor with alcohol (injected inside “under pressure”, by the means of the syringe) while spinning its rotor with your fingers, fixes this problem
Good luck.
- disks vary in reflectivity (a lot - I measured RF signal amplitude difference of 0.3 - 0.4 V PP)
- thickness (focus servo); you already mentioned there's nothing that could be done...?
- let’s assume that the position of TOC is at the same radial distance on all discs, so this would not be a variable, right?
- disc weight; check if the spindle servo can easily compensate for a little of additional ‘stress‘ that you can apply by placing your finger on a disc while it’s playing… If the servo does not correct, the spindle motor may need a good wash in isopropyl alcohol. The commutators get shorted from a long use and a lot of graphite deposits, resulting in a reduced torque capability. Washing the inside of the motor with alcohol (injected inside “under pressure”, by the means of the syringe) while spinning its rotor with your fingers, fixes this problem
Good luck.
Last edited:
It's a Brushless Motor in the CDM-1 MKII so no Commutator.
But thanks for the suggestions. As above, I think I may have to re-investigate the Spindle Motor Shaft within the chassis (non-removable (unless anybody knows different)) and bathe in oil.
Not had chance to look at it again as am also stuck on a CD-63 MKII (Marantz) but that's perhaps for another thread on here !!
Thanks for the suggestions both,
P.
But thanks for the suggestions. As above, I think I may have to re-investigate the Spindle Motor Shaft within the chassis (non-removable (unless anybody knows different)) and bathe in oil.
Not had chance to look at it again as am also stuck on a CD-63 MKII (Marantz) but that's perhaps for another thread on here !!
Thanks for the suggestions both,
P.
then.- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.