Rotel 865Bx sounds super fast

[[email protected]]

Hi Gents,

I have a rotel 865bx that has a problem. I have not worked on
players, so any help would be appreciated.

The problem is that after I insert a CD, and hit play, sometimes
the counter speeds up and the music sounds super fast. If I tilt the
player slightly, it sometimes stops. I have a couple of general ideas.

1) Alignment problem?

2) Intermittent that resolves when the pc board is flexed slightly?

3) Other?

Thanks.
Steve

 

[[email protected]]

Is this skipping forward or it the pitch high like the chipmunks ?

From what I know, if the pitch goes high you probably need a CD

player. If it is skipping forward one of the sensors in the pickup may
be partially occluded. If you can figure out how to set the tracking
you might be able to compensate. Also, pickups are not all that
expensive anymore, that is if you can get it.

Is there anything special about this player that makes it worth
fixing ? Even if it is an older unit and serves you well, that might
make it worth it. If it has a metal to plastic ratio that can be
detected, it may be worth it.

If it is new junk just toss it.

JURB

 

[James Sweet]

Hi Gents,

I have a rotel 865bx that has a problem. I have not worked on
players, so any help would be appreciated.

The problem is that after I insert a CD, and hit play, sometimes
the counter speeds up and the music sounds super fast. If I tilt the
player slightly, it sometimes stops. I have a couple of general ideas.

1) Alignment problem?

2) Intermittent that resolves when the pc board is flexed slightly?

3) Other?

Thanks.
Steve

If the pitch has gone way up, I would look at the oscillator driving the
DAC, that's about the only thing that can affect the playback speed.

 

[Arfa Daily]

If the pitch has gone way up, I would look at the oscillator driving the
DAC, that's about the only thing that can affect the playback speed.

That ain't quite exactly so, James. If the player is 'skipping'
continuously, that can give the impression that it is going fast in the same
way as when fast forward is pressed. Just about all 'standard' players fast
forward by 'grab a block - skip five, grab a block - skip five etc '. If the
player is really going fast as a result of clock trouble, the pitch of the
playback sound will be altered, much as the pitch control alters things on
disco CD decks. Otherwise, yes, I agree with you that it would have to be a
clock issue.

Perhaps the OP could confirm what he means exactly by "super fast". If it is
a rapid skip, as I suspect it might be, the very first thing is to make sure
that it is not something really simple like a button-push issue, and that
the fast forward button is not being mechanically pushed somehow, in a way
that gets resolved when the player is tipped / twisted. After that, it would
be a case of removing the top, and observing the actions of the optical
block and its drive gears when the problem is occuring. The drive for the
sled should only be activated every 2 to 5 seconds or thereabouts. You
should see the drive gear rotate a few teeth, and then stop. No overshoot,
no shuffling about. Overshoot is often a sign of mechanical issues with the
sled sticking. Erratic behaviour or shuffling is often a sign of a weak or
dirty laser. You might try cleaning the lens just for sport.

Other than that, it will be a case of just gently poking around the PCB with
the butt end of a ballpoint pen, to see if you can locate an area which
instigates or clears up the problem when disturbed. It could of course be an
issue internal to the laser, in which case, poking the PCB is unlikely to
yield a result.

Finally, do not be tempted to make any adjustments - mechanical or
electronic. Even if it has any adjustments - and many players don't now - it
is unlikely that they would be the cause of the sort of problems that you
are experiencing, and adjusting them without an intimate knowledge of what
they do, is likely to compound the original problem, and in the case of the
laser power pot, may cause irreversible damage to the laser.

Arfa

 

[[email protected]]

That ain't quite exactly so, James. If the player is 'skipping'
continuously, that can give the impression that it is going fast in the same
way as when fast forward is pressed. Just about all 'standard' players fast
forward by 'grab a block - skip five, grab a block - skip five etc '. If the
player is really going fast as a result of clock trouble, the pitch of the
playback sound will be altered, much as the pitch control alters things on
disco CD decks. Otherwise, yes, I agree with you that it would have to be a
clock issue.

Perhaps the OP could confirm what he means exactly by "super fast". If it is
a rapid skip, as I suspect it might be, the very first thing is to make sure
that it is not something really simple like a button-push issue, and that
the fast forward button is not being mechanically pushed somehow, in a way
that gets resolved when the player is tipped / twisted. After that, it would
be a case of removing the top, and observing the actions of the optical
block and its drive gears when the problem is occuring. The drive for the
sled should only be activated every 2 to 5 seconds or thereabouts. You
should see the drive gear rotate a few teeth, and then stop. No overshoot,
no shuffling about. Overshoot is often a sign of mechanical issues with the
sled sticking. Erratic behaviour or shuffling is often a sign of a weak or
dirty laser. You might try cleaning the lens just for sport.

Other than that, it will be a case of just gently poking around the PCB with
the butt end of a ballpoint pen, to see if you can locate an area which
instigates or clears up the problem when disturbed. It could of course be an
issue internal to the laser, in which case, poking the PCB is unlikely to
yield a result.

Finally, do not be tempted to make any adjustments - mechanical or
electronic. Even if it has any adjustments - and many players don't now - it
is unlikely that they would be the cause of the sort of problems that you
are experiencing, and adjusting them without an intimate knowledge of what
they do, is likely to compound the original problem, and in the case of the
laser power pot, may cause irreversible damage to the laser.

Arfa- Hide quoted text -

- Show quoted text -

Thanks gents. Sometimes it just sounds like Alvin for a whole song.
Other times one just hears a blip for an instant, sounds ok for
several seconds, and then blips again, randomly. Sometimes, I can lift
the player on one side and it reverts back to normal. I have cleaned
the optics, cleaned the CDs etc.

Again, thanks for your replies. It is much appreciated.
Steve

 

[James Sweet]

Thanks gents. Sometimes it just sounds like Alvin for a whole song.
Other times one just hears a blip for an instant, sounds ok for
several seconds, and then blips again, randomly. Sometimes, I can lift
the player on one side and it reverts back to normal. I have cleaned
the optics, cleaned the CDs etc.

Again, thanks for your replies. It is much appreciated.
Steve

Open it up and poke around with a stick, ballpoint pen works well. Sounds
like a bad connection somewhere is causing a clock issue, could be a cracked
timing crystal as well.

 

[[email protected]]

Thanks James.

I think I found the problem. I soldered alot of suspect
connections, but still no luck. Then I worked around the basket and
low and behold, touching the top that holds the Cd in place would
cause the problem. I checked the springs and one seemed a little
loose. One of the plastic 'retainers' the spring connects too was
cracked and bent. I repaired it and reattached the spring and all
seems ok, at least on the bench.
I will check tonight at home and see if it still works ok.

Thanks again James and others.
Steve