TBH I'm not keen on working on audio stuff - especially ones that have
mechanical bits and servos and stuff, so I may even weigh up the cost of
someone else having a look against the price of a new one.

The CD plays normally for about an hour then the spindle motor gradually
becomes erratic, slowing, stopping and occasionally going backwards, I've
only had it about 4 years, which seems a bit soon to bin it so I wondered if
its a stock fault anyone can tell me where to look for?

TIA.

ian field wrote in message
...
TBH I'm not keen on working on audio stuff - especially ones that have
mechanical bits and servos and stuff, so I may even weigh up the cost of
someone else having a look against the price of a new one.

The CD plays normally for about an hour then the spindle motor gradually
becomes erratic, slowing, stopping and occasionally going backwards, I've
only had it about 4 years, which seems a bit soon to bin it so I wondered
if
its a stock fault anyone can tell me where to look for?

TIA.



Prop it up at an angle for a few hours and see if the malfunction occurs
much earlier or not at all then probably mechanical/ connection problem than
electronic control problem. If mechanical then break/remake all connections
would be a good start.

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

"N Cook" wrote in message
...
ian field wrote in message
...
TBH I'm not keen on working on audio stuff - especially ones that have
mechanical bits and servos and stuff, so I may even weigh up the cost of
someone else having a look against the price of a new one.

The CD plays normally for about an hour then the spindle motor gradually
becomes erratic, slowing, stopping and occasionally going backwards, I've
only had it about 4 years, which seems a bit soon to bin it so I wondered
if
its a stock fault anyone can tell me where to look for?

TIA.



Prop it up at an angle for a few hours and see if the malfunction occurs
much earlier or not at all then probably mechanical/ connection problem
than
electronic control problem. If mechanical then break/remake all
connections
would be a good start.

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

When it first packed up I replaced it with a seriously cheap & nasty deck,
so I carried on using the Philips speakers and put the old deck in the box
with the tacky plastic speakers, recently I borrowed the tacky speakers and
while I had the box open had another play with the Philips deck. Short of
space to set it up in, it was on an uneven surface anyway and I patted it
about a bit to see if there were any glaringly conspicuous dry joints/loose
connections, its hard to tell with erratic behaviour but patting it about
didn't make a noticeable difference.

"ian field" wrote in message
...

"N Cook" wrote in message
...
ian field wrote in message
...
TBH I'm not keen on working on audio stuff - especially ones that have
mechanical bits and servos and stuff, so I may even weigh up the cost of
someone else having a look against the price of a new one.

The CD plays normally for about an hour then the spindle motor gradually
becomes erratic, slowing, stopping and occasionally going backwards,
I've
only had it about 4 years, which seems a bit soon to bin it so I
wondered
if
its a stock fault anyone can tell me where to look for?

TIA.



Prop it up at an angle for a few hours and see if the malfunction occurs
much earlier or not at all then probably mechanical/ connection problem
than
electronic control problem. If mechanical then break/remake all
connections
would be a good start.

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

When it first packed up I replaced it with a seriously cheap & nasty deck,
so I carried on using the Philips speakers and put the old deck in the box
with the tacky plastic speakers, recently I borrowed the tacky speakers
and while I had the box open had another play with the Philips deck. Short
of space to set it up in, it was on an uneven surface anyway and I patted
it about a bit to see if there were any glaringly conspicuous dry
joints/loose connections, its hard to tell with erratic behaviour but
patting it about didn't make a noticeable difference.

Hi Ian, how's it going ? Did you know that Steve is hoping to get T @ H
going again soon as a web based publication? Different name again though ...

Is that one of the Philips units that has the three-player mech with the
trays that slide over one another ? If so, it's quite likely that the laser
is either dusty or worn. Be warned though that this is not an easy mech to
dismantle to get at the laser. There are timing issues if you accidentally
get it screwed up, which is easy enough to do, even without dismantling it.
Unless you have the instructions, or have done a lot of them, you would
never figure it out by trial and error ... Just as a matter of interest, the
electronics and spindle motors on these are generally pretty reliable.

Arfa

"Arfa Daily" wrote in message
...

"ian field" wrote in message
...

"N Cook" wrote in message
...
ian field wrote in message
...
TBH I'm not keen on working on audio stuff - especially ones that have
mechanical bits and servos and stuff, so I may even weigh up the cost
of
someone else having a look against the price of a new one.

The CD plays normally for about an hour then the spindle motor
gradually
becomes erratic, slowing, stopping and occasionally going backwards,
I've
only had it about 4 years, which seems a bit soon to bin it so I
wondered
if
its a stock fault anyone can tell me where to look for?

TIA.



Prop it up at an angle for a few hours and see if the malfunction occurs
much earlier or not at all then probably mechanical/ connection problem
than
electronic control problem. If mechanical then break/remake all
connections
would be a good start.

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

When it first packed up I replaced it with a seriously cheap & nasty
deck, so I carried on using the Philips speakers and put the old deck in
the box with the tacky plastic speakers, recently I borrowed the tacky
speakers and while I had the box open had another play with the Philips
deck. Short of space to set it up in, it was on an uneven surface anyway
and I patted it about a bit to see if there were any glaringly
conspicuous dry joints/loose connections, its hard to tell with erratic
behaviour but patting it about didn't make a noticeable difference.

Hi Ian, how's it going ? Did you know that Steve is hoping to get T @ H
going again soon as a web based publication? Different name again though
...

Is that one of the Philips units that has the three-player mech with the
trays that slide over one another ? If so, it's quite likely that the
laser is either dusty or worn. Be warned though that this is not an easy
mech to dismantle to get at the laser. There are timing issues if you
accidentally get it screwed up, which is easy enough to do, even without
dismantling it. Unless you have the instructions, or have done a lot of
them, you would never figure it out by trial and error ... Just as a
matter of interest, the electronics and spindle motors on these are
generally pretty reliable.

Arfa


Its a single CD player with synth tuned AM/FM and cassette, the CD deck is
on top and the "lid" flips up like the lid on a wheely bin, there's no CD
transport system or drawer - the CD is simply put on the exposed hub.

When the spindle turns correctly it plays ok although I did try one of those
laser cleaning disks with the little brushes on and a bottle of iso-propyl.

"ian field" wrote in message
...

"Arfa Daily" wrote in message
...

"ian field" wrote in message
...

"N Cook" wrote in message
...
ian field wrote in message
...
TBH I'm not keen on working on audio stuff - especially ones that have
mechanical bits and servos and stuff, so I may even weigh up the cost
of
someone else having a look against the price of a new one.

The CD plays normally for about an hour then the spindle motor
gradually
becomes erratic, slowing, stopping and occasionally going backwards,
I've
only had it about 4 years, which seems a bit soon to bin it so I
wondered
if
its a stock fault anyone can tell me where to look for?

TIA.



Prop it up at an angle for a few hours and see if the malfunction
occurs
much earlier or not at all then probably mechanical/ connection problem
than
electronic control problem. If mechanical then break/remake all
connections
would be a good start.

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

When it first packed up I replaced it with a seriously cheap & nasty
deck, so I carried on using the Philips speakers and put the old deck in
the box with the tacky plastic speakers, recently I borrowed the tacky
speakers and while I had the box open had another play with the Philips
deck. Short of space to set it up in, it was on an uneven surface anyway
and I patted it about a bit to see if there were any glaringly
conspicuous dry joints/loose connections, its hard to tell with erratic
behaviour but patting it about didn't make a noticeable difference.

Hi Ian, how's it going ? Did you know that Steve is hoping to get T @ H
going again soon as a web based publication? Different name again though
...

Is that one of the Philips units that has the three-player mech with the
trays that slide over one another ? If so, it's quite likely that the
laser is either dusty or worn. Be warned though that this is not an easy
mech to dismantle to get at the laser. There are timing issues if you
accidentally get it screwed up, which is easy enough to do, even without
dismantling it. Unless you have the instructions, or have done a lot of
them, you would never figure it out by trial and error ... Just as a
matter of interest, the electronics and spindle motors on these are
generally pretty reliable.

Arfa


Its a single CD player with synth tuned AM/FM and cassette, the CD deck is
on top and the "lid" flips up like the lid on a wheely bin, there's no CD
transport system or drawer - the CD is simply put on the exposed hub.

When the spindle turns correctly it plays ok although I did try one of
those laser cleaning disks with the little brushes on and a bottle of
iso-propyl.

Ah, OK. I know which one it is now. It's worth just giving the lens a
'proper' clean with IPA and a cotton bud. I've never been much enamoured
with the bristled cleaning discs. At best they don't do a very good job, and
at worst, I've seen the bristles get caught in a laser's superstructure, and
do damage to the lens carrier ...

Beyond that, the most likely problem is the laser itself. Stopping reading
after some period of operation, is a fairly common failure mode.

Arfa

"Arfa Daily" wrote in message
...

"ian field" wrote in message
...

"Arfa Daily" wrote in message
...

"ian field" wrote in message
...

"N Cook" wrote in message
...
ian field wrote in message
...
TBH I'm not keen on working on audio stuff - especially ones that
have
mechanical bits and servos and stuff, so I may even weigh up the cost
of
someone else having a look against the price of a new one.

The CD plays normally for about an hour then the spindle motor
gradually
becomes erratic, slowing, stopping and occasionally going backwards,
I've
only had it about 4 years, which seems a bit soon to bin it so I
wondered
if
its a stock fault anyone can tell me where to look for?

TIA.



Prop it up at an angle for a few hours and see if the malfunction
occurs
much earlier or not at all then probably mechanical/ connection
problem than
electronic control problem. If mechanical then break/remake all
connections
would be a good start.

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

When it first packed up I replaced it with a seriously cheap & nasty
deck, so I carried on using the Philips speakers and put the old deck
in the box with the tacky plastic speakers, recently I borrowed the
tacky speakers and while I had the box open had another play with the
Philips deck. Short of space to set it up in, it was on an uneven
surface anyway and I patted it about a bit to see if there were any
glaringly conspicuous dry joints/loose connections, its hard to tell
with erratic behaviour but patting it about didn't make a noticeable
difference.

Hi Ian, how's it going ? Did you know that Steve is hoping to get T @ H
going again soon as a web based publication? Different name again though
...

Is that one of the Philips units that has the three-player mech with the
trays that slide over one another ? If so, it's quite likely that the
laser is either dusty or worn. Be warned though that this is not an easy
mech to dismantle to get at the laser. There are timing issues if you
accidentally get it screwed up, which is easy enough to do, even without
dismantling it. Unless you have the instructions, or have done a lot of
them, you would never figure it out by trial and error ... Just as a
matter of interest, the electronics and spindle motors on these are
generally pretty reliable.

Arfa


Its a single CD player with synth tuned AM/FM and cassette, the CD deck
is on top and the "lid" flips up like the lid on a wheely bin, there's no
CD transport system or drawer - the CD is simply put on the exposed hub.

When the spindle turns correctly it plays ok although I did try one of
those laser cleaning disks with the little brushes on and a bottle of
iso-propyl.

Ah, OK. I know which one it is now. It's worth just giving the lens a
'proper' clean with IPA and a cotton bud. I've never been much enamoured
with the bristled cleaning discs. At best they don't do a very good job,
and at worst, I've seen the bristles get caught in a laser's
superstructure, and do damage to the lens carrier ...

Beyond that, the most likely problem is the laser itself. Stopping reading
after some period of operation, is a fairly common failure mode.

Arfa


Would a faulty laser cause the spindle motor to become erratic?

The disk reads OK until the spindle motor starts playing up.

In article , ian field wrote:
TBH I'm not keen on working on audio stuff - especially ones that have
mechanical bits and servos and stuff, so I may even weigh up the cost of
someone else having a look against the price of a new one.

The CD plays normally for about an hour then the spindle motor gradually
becomes erratic, slowing, stopping and occasionally going backwards, I've
only had it about 4 years, which seems a bit soon to bin it so I wondered if
its a stock fault anyone can tell me where to look for?

I fixed a "Hifi separates" CD player with identical symptoms a few
years ago. It had a pair of transistors (one NPN one PNP, to + and - rails)
driving the spindle motor, and one was leaky (getting worse when hot).

It's the only CD player I've ever seen where the spindle motor
run the wrong way at any time.

Mike.

"Remove _ for valid address" wrote in message
...
In article , ian field wrote:
TBH I'm not keen on working on audio stuff - especially ones that have
mechanical bits and servos and stuff, so I may even weigh up the cost of
someone else having a look against the price of a new one.

The CD plays normally for about an hour then the spindle motor gradually
becomes erratic, slowing, stopping and occasionally going backwards, I've
only had it about 4 years, which seems a bit soon to bin it so I wondered
if
its a stock fault anyone can tell me where to look for?

I fixed a "Hifi separates" CD player with identical symptoms a few
years ago. It had a pair of transistors (one NPN one PNP, to + and -
rails)
driving the spindle motor, and one was leaky (getting worse when hot).

It's the only CD player I've ever seen where the spindle motor
run the wrong way at any time.

Mike.


It is very common for the motor to run backwards on any make and model, when
the spindle servo loses lock. The spindle motor running 'erratically' is
more likely to be a symptom, rather than the cause. Control of the spindle
servo is as a direct result of correctly decoding the servo control info in
the recovered data stream. If the data stream starts to become corrupt to
the point where the software and hardware error correction systems can no
longer derive valid control data, the servo will lose lock, and the
rotational speed will become erratic. This further exacerbates the
situation, until the whole servo loop goes unstable, which is when the disc
is likely to either start spinning backwards, or comes to a stop with
twitches or pulses of brief rotation. The commonest cause for the data
becoming corrupt, is a defective laser. That's not to say that a similar
problem *can't* be caused by a defective motor, or the external control
circuitry, which these days is either contained all in one chip, or in a
servo processor chip plus a motor driver chip.

Usually, problems with the motor itself, are confined to DVD players, where
they are worked much harder with the higher rotational speed involved, so
tend to have a shorter lifespan. I have had faulty motors on CD players -
notably the Pioneers from a few years back, and some Panasonics - but on
other makes and models, they are fairly rare, compared to bad lasers.
Usually, if you have a motor problem, it will start to show on later tracks
on a long disc. This is because CD players use constant angular velocity,
which means that the disc rotates slower as the laser moves towards the
outside of the disc. Any brushgear wear leading to poor motor performance,
shows up worse at lower rotational speeds. You can get an idea if this is
the problem, by playing a couple of tracks at the start of a long disc, to
warm up the motor, then forward skipping straight away to a late track near
the end. A dicky motor will usually show up at that point. If it doesn't
immediately start giving trouble, you might also find that it has become
very 'tap sensitive' at this point, as the data is getting close to being
compromised by poor rotational stability.

Poor motors also often show a marked increase in commutation noise, measured
with a 'scope directly across the motor terminals. If you can find either a
testpoint or an IC pin marked "RF", you can perform a more 'technical'
diagnosis by observing the eye pattern on this point. Well defined and
stable 'diamonds' in the pattern indicate stable rotational speed.
Twittering of, or the diamonds looking out of focus, particularly on later
tracks, can indicate a poor motor. The size of the RF waveform is a good
indicator of laser condition. On most players, if there is a testpoint, the
expected level on it is about 0.8 to 1.2v p-p. If the level drops off over
playing time, this normally indicates a worn laser.

Hope that clears up a few points, and helps with getting to the bottom of
it.

Arfa