[long] Help!!! CD spinning sloooow

[seppstefano]

Hi all,
just after reading a lot on jumping CD, it's my turn now (sadly)...

A couple of evening ago, while trying to attach to a wall a decorative
photo given by my wife, I accidentally pushed the test switch on the
general switch located on distributor mains, while music was playing...
(a CD was playing, indeed).

Then, definitely not smart at all, I pushed it again in order to light
all the house on.

Ok, I came back to my music and, after a while I seemed a CD was
"plopping", I listened to small "pop, plip" and "plop" in music flow. I
swapped the CD, yet the problem persisted... more some CD started
randomly refusing spinning when inserted.

I disconnected the player, opened it and tried to understand something
more... it seemed the motor metal spindle lacks some torque when trying
to spinning CD (the whole mechanics is based on a 2 metal rails unit,
laser is a SANYO numbered N0503705).

I added a gummy ring, to help spindle grip the CDs, but it didn't solve
the problem. More, when the CD plays I slowed further more the CD with a
finger, the problems heard, seems of same nature: some clicks and pops
which are louder and more distinguishable as the slowing increases.

So, I thought the problem is rotational constance of the motor. Is it
ok? Is it possible to fix it?

Below a list of IC and pots seen on the digital/control board:
IC: Sanyo LC6538D 1L1 4814

pots:
P002 E/F BAL 103
P001 T.DC-OFF 104
P003 T-GAIN 502
P005 F-GAIN 203
P007 FREE RUN 204

Is perhaps worth trying to adjust some pot, if anything changed in
electrical characteristics of CD player (perhaps due to current inrush),
or better to look for another mechanics, or replacing the only motor is
feasible???

Sorry for LONG LONG post...

TIA,

Stefano

[hjelm]

My first guess would be that you have blown a regulator somewhere in the CD player. I would check all voltages first that they are ok. Also check the motor drive circuit.

[seppstefano]

Thanks a lot for replying Hjelm,
yesterday evening I kept on listening to it apparently w/o popping problems.

So, I argue that motor is ok. By carefully inspecting boards while looking for burning signs, I found a small electrolytic cap, 10uF/16V Rubycon, with a small opaque shade on top.

Every other cap seem bright, only this one shows this small area (do you know on the silver color (I guess Alu) circular area top of electrolytics).

The cap is located quite near the Sanyo controller chip.

Do you think that replacing it would be a possible solution?

How is it possible that yesterday the player kept on playing correctly several CDs, even when subsequently powered on and off???

Thanks for replying,

Stefano

[hjelm]

Guessing wildly here but you could have had a short in the cap which has burned off now. This could have caused the supply to sag due to the load.

[seppstefano]

Thanks for your help Hjelm,
it was my thought, too. In that case it seems I have to look for such a cap, in order to replace it.

Thing I cannot understand is why yesterday the popping effect was not there...

Ciao,

Stefano

[DragonMaster]

Reapplying power gave a power surge to the CDP.(That's why you should unplug computer, TV... before applying power) I got a CD player that was doing the same thing, I took an older revision drive and it was OK.

I think the pickup was to it's end, but I wasn't using the other player(That used a better pickup).

Thing I cannot understand is why yesterday the popping effect was not there...

Try playing it for about 2 hours, if it restarts, the pickup that might have been over-powered.(My CDP was doing this)

Or the cap maybe had over-volted and restabilized. Change it since it looks damaged.

[seppstefano]

Thank you all,
I'll arrange a listening session this evening and will inspect again more accurately the digi board.

Ciao,

Stefano

[seppstefano]

well yesterday evening the player sounded correctly for 2-3 hours, I changed CDs and pieces w/no problems.

I'll look for a good 10uF 16v electrolytic cap to replace anyway the shaded one.

In this case is a swap with a higher voltage cap presumably a better (safer) option???

Ciao and thanks for your kind feedback,

Stefano

[DragonMaster]

Yes, put some higher voltage caps. If the circuit runs at eg. 15v a 16v cap is not enough, use higher voltage. Companies are using the lowest voltage caps they can, but after a while, they leak.

[seppstefano]

Hi hjelm, Dragonmaster,
after a whole day of correct sound (really good after putting some bubblewrap and a slate under the cdp), the popping effect re-appeared this morning on the CDP (perhaps a whole day playing cooked the "shaded" cap inside?)...

It happens I don't have the 10uF cap around, I have some 22uF/25v and 100uF/50v. Do you think that using a different (higher cap) might be ok, as the cap quite near the motor controller unit might be a sort of reservoir for the IC SANYO controlling it, or is better to replace with same capacitance (and higher voltage, this for sure)?

Thanks for your help.

Ciao,

Stefano