Spindle Motor substitution in SONY CD Players

[Old Sparky]

Recently I was asked if I could repair the CD Player in a SONY Midi HiFi System in which bith the spindle and sled motors had developed high resistance.  Not wishing to pay CHS £111 for a replacement mechanism, it occured to me that, since, AFAIK,  the spindle &  sled motors in all the common SONY & SANYO mechanisms are very similar, if I obtained a KSM213CCM mech. and swapped over the motors, a repair could be effected at far less cost ( I should know better!) so I purchased from CPC one of these, and proceeded to swap the motors.  In the case of the spindle motor I also replaced the turnatable on the spindle motor with the correct one from the original motor, taking care to set the height at 18mm above the deck plate as in the original.  However, when I refitted the mech. to the player and switched on, the sled motor worked OK, the disc loaded and clamped in place, but didn't rotate.  A 'buzzing' kind of interference was heard in the speakers, so I switched off and rechecked things.  Not finding any thing obviously wrong, I switched on again, measuring about 3.5v at the spindle motor +ve for a few seconds, but still no operation.  The 'disc in' switch is working OK, and the spindle motor turns freely if rotated by hand.  I should add that the mechanism had been left dismantled for 3 or 4 weeks, with the ribbon cable which connects the mech. PCB to the main circuit biard completely removed.  Could this have caused  a fault to occur on the mech. PCB?  Both new motors measure ca. 11 ohms 'cold' resistance, which seems perfectly normal to me.  NB I don't have the System or original CD mech. in front of me, and can't remember the model nos. of either!

[Refugee]

Are you sure that you have the wires connected the right way round?
It would just cut out if the motor rotated in the wrong direction.

[Old Sparky]

99%, but I'll have to check. The motors are sodered directly to the control PCB, and the +ve teminal is indicated by a red dot adjacent to the terminal.

[Refugee]

You will need to look at the way the chip is wired as some layouts have errors that make the polarity wrong on the board silk screen.
Checking the direction of rotation with a battery is the only way to be sure.

[Old Sparky]

Having checked the spindle motor in question, and two others, independantly of any control circuitry, using my Bench PSU, i find that all 3 rotate in a clockwise direction if +ve is applied to the terminal marked with a red dot and -ve to the other terminal, which seems perfectly logical to me. However all three motors will quite happily turn in an anticlockwise direction if the polarity of the supply is reversed. Current consumption of a few mA @ 5v is the same whichever polarity supply is used, which again, seems logical to me, since spindle motors of this tyes are, AFAIK, the same type as sled motors, but with a spindle ca 25mm long, rather than the about 10-12mm length shafts fitted to sled motors. However, I did measure the spindle of the new spindle motor and found it to be a few mm longer than that of the original, so, although I couldn't see clearly whether the spindle was fouling the disc clamp, I decided to use a motor whose spindle length was the same as that of the original in the hope that it would cure the trouble (it didn't!!). I'm now beginning to wonder if there isn't a fault on what SONY call the 'BD' board -i.e. the control PCB mounted underneath the CD mechanism chassis. Guess I'll have to look for a circuit diagram or service manual for the CDP-EX100 which, hopefully will help me find the answer to the problem!

[Refugee]

Have you done the caps around the driver chip?

[Old Sparky]

In a word, No! I guess they could be suspect.  The player is in my workshop, so it'll be Monday before I get back to it.

[Murphyv310]

Hi.
On a Sony dont forget the sequence. Sled reset, then Focus, then spin up.
If the sled reset is wrong or the laser cant find focus then you wont get spin up.

What optical block is it? KSS240A is notoriously known as a pig. KSS150A = KSS210A = KSS212A
The "B" versions are for portable use

[Old Sparky]

According to the service manual it's a KSS-213B/K-RP (Assuming the page I printed off a couple of days ago is for the EX-100 not the CDP-M43.)
The EX100 is in my workshop, so I can't check it this morning, and I don't want to open up my M43! Are there any known issues with the KSS-213B?

[Old Sparky]

Via the HiFi Engine website I've just confirmed that the CDP-M43's laser is a KSM-240 ( My M43 is working well, so no probs. there!), thus the diagram I printed is for the EX100, and it's laser is definitely a KSS-213B/K-RP. In the case of the system I'm in the process of repairing it is also a SONY original laser, not a 'pattern' one of unknown origin.