CD Player Problem

[cuddles]

Could someone explain what the problem with my CD player might be? It's a Myryad MC100 about 12 years old and recently I've noticed that sometimes I hear a fuzziness during loud passages of music - it pulses with the beat and on crescendos. I've ruled out the discs being dirty so the problem must lie with the player.
Is it a sign of a dirty laser lens which just needs cleaning or is it a sign of something more significant?
Cheers in advance.

[PLINIUS]

Could someone explain what the problem with my CD player might be? It's a Myryad MC100 about 12 years old and recently I've noticed that sometimes I hear a fuzziness during loud passages of music - it pulses with the beat and on crescendos. I've ruled out the discs being dirty so the problem must lie with the player.
Is it a sign of a dirty laser lens which just needs cleaning or is it a sign of something more significant?
Cheers in advance.
12 yrs is a fairly good effort for a laser, but you might get away with a proper clean.

[Reid Malenfant]

I think it's more likely to be some electronic component on it's way out, possibly any electrolytic capacitors that may be in the signal path or in the power supply.

The first thing that tends to happen with a dirty laser is it'll start skipping at odd times, or fail to read a disc or two on odd occasions. as things progress it becomes more prevalent.

No harm in giving the laser lens a clean though ;)

[cuddles]

No harm in giving the laser lens a clean though ;)

I'll give it a go :). Any good ones out there?

[Reid Malenfant]

Never ever use a CD lens cleaner :nono:

Get yourself some Isopropyl Alcohol, also known as Isoproponol from a chemist. You only need a small amount, but you'll probably get a 100ml bottle.

If they ask what you want it for, say cleaning cassette deck heads :)

Pop the lid off of the player with it unplugged from the mains, if you can't see the laser in the mechanism, plug it in, stand back so you don't have any chance of looking into the laser, switch it on & open the draw & then switch it off with the draw open. Then unplug it to be safe ;)

At this point get a cotton bud & lightly wet it with the Isoproponol & very gently apply it to the lens of the laser, maybe use a circular motion, but be very gentle. a few seconds, maybe 10, then use the dry end of the cotton bud to dry the thing off...

Put the lid back on & you should be good to go :cool:

[synsei]

This is where I buy my IPA (http://www.ebay.co.uk/itm/100ml-bottle-isopropanol-Alcohol-99-inc-free-posting-Isopropyl-liquid-cleaner-/280929086671?pt=LH_DefaultDomain_3&hash=item4168adaccf#ht_819wt_1163). He's a top bloke and delivery is nice 'n' speedy ;)

[cuddles]

I've got surgical spirit kicking around. Good or no good? :scratch:

[Reid Malenfant]

Too many impurities, it might leave traces of itself on the lens.

IPA as Dave mentioned & myself is the purest alcohol that you or I can legally purchase, it's also cheap :)

[Yomanze]

I think it's more likely to be some electronic component on it's way out, possibly any electrolytic capacitors that may be in the signal path or in the power supply.

The first thing that tends to happen with a dirty laser is it'll start skipping at odd times, or fail to read a disc or two on odd occasions. as things progress it becomes more prevalent.

No harm in giving the laser lens a clean though ;)

Agreed that it's probably some component on the way out, I would be looking to replace the servo capacitors as these are common things to go & might explain some of the strange noises.

[nat8808]

Pulsing with the beat souns like a power issue to something at points when the music is the loudest, when the beat slams down.

I'd guess a capacitor somewhere. Could muting transistors do someing similar when on their way out?

I bet the laser is fine. The laser is all about reading digital data so you're not going to get analogue effects on the output from the data not being read properly.

I bet the lens is fine too..

Search diyaudio.com forum or post on it for help - many many many cd repair engineers on there as well as designers and experienced diy fixers on there.

[cuddles]

Thanks for all your replies. Laid up with lurgy at the moment so I'll give it a check up soon ;)

[JimC]

The Laser too is an electronic component don't forget.

Laser emitting and receiving diodes are semi-conductor devices. In my experience it is more often than not the receiving diode that starts to fail first in a laser, the emitting diode continuing to shine brightly.

The failing receiving diode can cause the RF waveform from it to become low (pk-pk AC Voltage). The top and bottom of this waveform are 'cut off' (basically) to give the EFM waveform used by the decoding I.C.'s thus reducing its level even further.
If still just about within specification the discs can still be read and played but with even slight marks or imperfections on the disc, this could cause what you are experiencing.

I would also think about replacing the Spindle Motor on a unit of this age. Dirty contacts on the commutator can cause it to spin at not quite the correct speed causing distortion in the audio.

Most players over the years have either Philips or Sony Lasers (Sanyo being another of the major manufacturers though) which can be found easily on the net as can the motors.
Do 'anti-stat' yourself when working around the laser. You can cause more damage than you are trying to cure if you don't.

Hope this all helps,

James.