Basic CD player in a micro music centre
 

No movements or laser light , totally dead CD player. Just -- in the
display.
Function sw and door latch sw ok. Plenty of 5V etc supplies around on the
chippery. Crystal and ceramic resonator have oscillation.
All 4 channel motor/focus driver o/p at 3.8V, all 4 inputs at 2.1V, disable
is set off ie operational.
Pressing all sm chip leads , no change
Swapping laser and carrier/motors section with another one laying around,
the same zilch. No dodgy electrolytics.
Is there something obvious I'm overlooking ?
Not worth spending a lot of time on but a good customer for other stuff.

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

Basic CD player in a micro music centre
 

"N Cook" wrote in message
...
No movements or laser light , totally dead CD player. Just -- in the
display.
Function sw and door latch sw ok. Plenty of 5V etc supplies around on the
chippery. Crystal and ceramic resonator have oscillation.
All 4 channel motor/focus driver o/p at 3.8V, all 4 inputs at 2.1V,
disable
is set off ie operational.
Pressing all sm chip leads , no change
Swapping laser and carrier/motors section with another one laying around,
the same zilch. No dodgy electrolytics.
Is there something obvious I'm overlooking ?
Not worth spending a lot of time on but a good customer for other stuff.


Can't think of anything that you seem to be overlooking. First place I would
have gone is the same as you - to the door switch. Even though the switch is
working ok in itself, I would still feel inclined to make sure that its
connections are making it all the way back to the micro, and doing something
ie pulling a pin to ground or whatever. I've had internal pull-up resistors
on micro pins fail. The only other thing that it's worth doing when all else
has failed, and you've given up, is to try a possible 'real' system reset,
by holding in the power button and applying power, and if that fails, a
'naughty' engineer's reset, by turning off and removing power, then hooking
a croc lead to ground, and stroking round every pin of every 'micro-ish' IC
both on the front panel, and the CD process board. I've known this to
restore screwed up system controls on a number of occasions. I got it
originally from a manufacturer's training course, but so far back in the dim
mists of time, I can't remember which one now ...

Arfa

Basic CD player in a micro music centre
 

"N Cook" wrote in message
...
No movements or laser light , totally dead CD player. Just -- in the
display.
Function sw and door latch sw ok. Plenty of 5V etc supplies around on the
chippery. Crystal and ceramic resonator have oscillation.
All 4 channel motor/focus driver o/p at 3.8V, all 4 inputs at 2.1V,
disable
is set off ie operational.
Pressing all sm chip leads , no change
Swapping laser and carrier/motors section with another one laying around,
the same zilch. No dodgy electrolytics.
Is there something obvious I'm overlooking ?
Not worth spending a lot of time on but a good customer for other stuff.

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



Don't forget the sled limit switch - brand and model info might help.

Mark Z.

Basic CD player in a micro music centre
 

Arfa Daily wrote in message
...

"N Cook" wrote in message
...
No movements or laser light , totally dead CD player. Just -- in the
display.
Function sw and door latch sw ok. Plenty of 5V etc supplies around on
the
chippery. Crystal and ceramic resonator have oscillation.
All 4 channel motor/focus driver o/p at 3.8V, all 4 inputs at 2.1V,
disable
is set off ie operational.
Pressing all sm chip leads , no change
Swapping laser and carrier/motors section with another one laying
around,
the same zilch. No dodgy electrolytics.
Is there something obvious I'm overlooking ?
Not worth spending a lot of time on but a good customer for other stuff.


Can't think of anything that you seem to be overlooking. First place I
would
have gone is the same as you - to the door switch. Even though the switch
is
working ok in itself, I would still feel inclined to make sure that its
connections are making it all the way back to the micro, and doing
something
ie pulling a pin to ground or whatever. I've had internal pull-up
resistors
on micro pins fail. The only other thing that it's worth doing when all
else
has failed, and you've given up, is to try a possible 'real' system reset,
by holding in the power button and applying power, and if that fails, a
'naughty' engineer's reset, by turning off and removing power, then
hooking
a croc lead to ground, and stroking round every pin of every 'micro-ish'
IC
both on the front panel, and the CD process board. I've known this to
restore screwed up system controls on a number of occasions. I got it
originally from a manufacturer's training course, but so far back in the
dim
mists of time, I can't remember which one now ...

Arfa



Perhaps stripping off at midnight and dancing around it on a full moon might
work as well.

Basic CD player in a micro music centre
 

"N Cook" wrote in message
...
Arfa Daily wrote in message
...

"N Cook" wrote in message
...
No movements or laser light , totally dead CD player. Just -- in the
display.
Function sw and door latch sw ok. Plenty of 5V etc supplies around on
the
chippery. Crystal and ceramic resonator have oscillation.
All 4 channel motor/focus driver o/p at 3.8V, all 4 inputs at 2.1V,
disable
is set off ie operational.
Pressing all sm chip leads , no change
Swapping laser and carrier/motors section with another one laying
around,
the same zilch. No dodgy electrolytics.
Is there something obvious I'm overlooking ?
Not worth spending a lot of time on but a good customer for other
stuff.


Can't think of anything that you seem to be overlooking. First place I
would
have gone is the same as you - to the door switch. Even though the switch
is
working ok in itself, I would still feel inclined to make sure that its
connections are making it all the way back to the micro, and doing
something
ie pulling a pin to ground or whatever. I've had internal pull-up
resistors
on micro pins fail. The only other thing that it's worth doing when all
else
has failed, and you've given up, is to try a possible 'real' system
reset,
by holding in the power button and applying power, and if that fails, a
'naughty' engineer's reset, by turning off and removing power, then
hooking
a croc lead to ground, and stroking round every pin of every 'micro-ish'
IC
both on the front panel, and the CD process board. I've known this to
restore screwed up system controls on a number of occasions. I got it
originally from a manufacturer's training course, but so far back in the
dim
mists of time, I can't remember which one now ...

Arfa



Perhaps stripping off at midnight and dancing around it on a full moon
might
work as well.


Only if it's a Philips ...

Arfa