I fixed my Aiwa CD Player!

[aasdf]

Hi, I have an old Aiwa CX-NA50 that I bought in 1998. It's a three CD
(3 CD) mini system. From the beginning it would "reject" certain CDs..
it would spin them a couple of times, with a slight clicking, might
bring up the track directories every once in awhile, but most often
would skip to the next cd. After about a year of this it wouldn't play
CDs much any more at all. It's been sitting in the closet since about
1999. Recently I took it out to play MP3s and XM Radio via an FM
transmitter because the little speakers are excellent.

Today I took it apart and fiddled with the little potentiometer
(potter, pot) inside the machine right next to (behind actually, a few
inches toward the rear of the machine) the laser. It was a chore
getting it apart and I had to take off the side and part of the back.
I turned the little potter about 1/8 turn counter-clockwise, and it
started working and now seems to read and play CDs. Whether this will
"burn out" the laser at some point is not a concern to me since it
wasn't working at all before. I tested it to make sure this was
actually the reason by turning the potter back into the original
position, and sure enough it failed to work again. So I'm reasonably
sure this is what's the matter with it, or a "kludge" to get around
what is really the matter.

Previously I had tried to clean the laser, to no avail. For those of
you who have faulty Aiwa systems you should know that there was a
class-action settlement a few years ago that offered to replair the
systems for free, because many of the systems had this problem. It is
a very common problem. Unfortunately the period of time to take
advantage of that has passed, so now you must do it yourself unless you
simply want to pitch the system or pay money to have someone else do
it.

So if your mini CD player is not reading the discs you put in, you may
want to try this fix. Do this at your own risk.

 

[Arfa Daily]

Hi, I have an old Aiwa CX-NA50 that I bought in 1998. It's a three CD
(3 CD) mini system. From the beginning it would "reject" certain CDs..
it would spin them a couple of times, with a slight clicking, might
bring up the track directories every once in awhile, but most often
would skip to the next cd. After about a year of this it wouldn't play
CDs much any more at all. It's been sitting in the closet since about
1999. Recently I took it out to play MP3s and XM Radio via an FM
transmitter because the little speakers are excellent.

Today I took it apart and fiddled with the little potentiometer
(potter, pot) inside the machine right next to (behind actually, a few
inches toward the rear of the machine) the laser. It was a chore
getting it apart and I had to take off the side and part of the back.
I turned the little potter about 1/8 turn counter-clockwise, and it
started working and now seems to read and play CDs. Whether this will
"burn out" the laser at some point is not a concern to me since it
wasn't working at all before. I tested it to make sure this was
actually the reason by turning the potter back into the original
position, and sure enough it failed to work again. So I'm reasonably
sure this is what's the matter with it, or a "kludge" to get around
what is really the matter.

Previously I had tried to clean the laser, to no avail. For those of
you who have faulty Aiwa systems you should know that there was a
class-action settlement a few years ago that offered to replair the
systems for free, because many of the systems had this problem. It is
a very common problem. Unfortunately the period of time to take
advantage of that has passed, so now you must do it yourself unless you
simply want to pitch the system or pay money to have someone else do
it.

So if your mini CD player is not reading the discs you put in, you may
want to try this fix. Do this at your own risk.

This is actually not good *general* advice. Be sure that the laser will now
totally fail in pretty short order. The laser pot is neither intended to be,
nor ever should be, adjusted with 99% of the lasers used in audio and DVD
equipment. It's setting is carefully determined at the factory as a result
of measuring several parameters. One notable exception is Pioneer, where
there is a proper laid down procedure for adjusting it.

I have repaired many thousands of Aiwas over the years, but far from saying
that laser failure in them is common because of any manufacturing or design
problem, I would venture that the reason I have seen so many, is that I
service them for the trade, and they were a very popular item, sold through
several of the large chains here, so as a value for money item, which I
believe they are, they outsold many other brands and models.

The laser employed in them is one of the KSS series from Sony, and these
lasers are extremely cheap anyway, so if you've gone to the trouble of
stripping the unit far enough to get at the pot, you might as well replace
the laser.

I am pleased for you that adjusting the pot got your unit going to your
satisfaction, but it was possible that the fault lay elsewhere, and
adjusting the laser would only have compounded the problem by resulting in
laser damage. For that reason, if no other, I would STRONGLY advise anyone
reading this thread, to NEVER adjust a laser as part of a diagnosis
procedure, unless it is a valid and manufacturer-recommended procedure. Some
lasers are very expensive ( and very reliable ), and altering the pot on
them, when the real problem may well be some two penny resistor, is likely
to result in a written off unit.

Arfa

 

[N Cook]

Hi, I have an old Aiwa CX-NA50 that I bought in 1998. It's a three CD
(3 CD) mini system. From the beginning it would "reject" certain CDs..
it would spin them a couple of times, with a slight clicking, might
bring up the track directories every once in awhile, but most often
would skip to the next cd. After about a year of this it wouldn't play
CDs much any more at all. It's been sitting in the closet since about
1999. Recently I took it out to play MP3s and XM Radio via an FM
transmitter because the little speakers are excellent.

Today I took it apart and fiddled with the little potentiometer
(potter, pot) inside the machine right next to (behind actually, a few
inches toward the rear of the machine) the laser. It was a chore
getting it apart and I had to take off the side and part of the back.
I turned the little potter about 1/8 turn counter-clockwise, and it
started working and now seems to read and play CDs. Whether this will
"burn out" the laser at some point is not a concern to me since it
wasn't working at all before. I tested it to make sure this was
actually the reason by turning the potter back into the original
position, and sure enough it failed to work again. So I'm reasonably
sure this is what's the matter with it, or a "kludge" to get around
what is really the matter.

Previously I had tried to clean the laser, to no avail. For those of
you who have faulty Aiwa systems you should know that there was a
class-action settlement a few years ago that offered to replair the
systems for free, because many of the systems had this problem. It is
a very common problem. Unfortunately the period of time to take
advantage of that has passed, so now you must do it yourself unless you
simply want to pitch the system or pay money to have someone else do
it.

So if your mini CD player is not reading the discs you put in, you may
want to try this fix. Do this at your own risk.

For anyone else seeing this in the archives etc.
You should have measured the ohmage of that preset to the nearest ohm with a
DVM/resistance first, so you could get back to the initial starting point ,
if you had made matters worse.

 

[N Cook]

For anyone else seeing this in the archives etc.
You should have measured the ohmage of that preset to the nearest ohm with a
DVM/resistance first, so you could get back to the initial starting point ,
if you had made matters worse.

afterthought.
Do not adjust this pot any more than 2 to 5 percent up or down of its
original setting, hence requirement to measure firstly.

 

[Arfa Daily]

afterthought.
Do not adjust this pot any more than 2 to 5 percent up or down of its
original setting, hence requirement to measure firstly.

However, as I said, it really should not be adjusted in the first place.
Some optical blocks are very sensitive to abuse, and even if setting the pot
back to the original point - which incidentally can usually be achieved by
setting the paint seal that you've fractured back to where it was ... - the
damage may already have been done, giving you the possibility that you now
have two faults. Unless you have the necessary diagnostic skills to know
exactly what you are doing, and which laser types are likely to respond, and
which to fail as a result of altering their pots, and are prepared to shell
out on a shiny new replacement, that still might not work if the problem is
elsewhere, then my strong recommendation has to be don't adjust the pot at
all, ever.

Arfa

 

[Meat Plow]

However, as I said, it really should not be adjusted in the first place.
Some optical blocks are very sensitive to abuse, and even if setting the pot
back to the original point - which incidentally can usually be achieved by
setting the paint seal that you've fractured back to where it was ... - the
damage may already have been done, giving you the possibility that you now
have two faults. Unless you have the necessary diagnostic skills to know
exactly what you are doing, and which laser types are likely to respond, and
which to fail as a result of altering their pots, and are prepared to shell
out on a shiny new replacement, that still might not work if the problem is
elsewhere, then my strong recommendation has to be don't adjust the pot at
all, ever.

Arfa

He had a soon to be 19 year old combo that's been sitting in the closet
for almost 8 years. No harm in tinkering with the laser pot.

 

[Mark D. Zacharias]

He had a soon to be 19 year old combo that's been sitting in the
closet for almost 8 years. No harm in tinkering with the laser pot.

The OP said 1998, not 1988...


I have no problem with a slight adjustment to get it going if cleaning
fails. In my experience the laser diode has a range if operating current
within which it's OK. Every cd player laser circuit has an APC circuit to
maintain diode current. As the laser weakens, the circuit juices it up some
anyway.
The OP's solution isn't perfect, to be sure - but the only alternative is to
replace the laser, which actually is a LOT more disassembly to remove the
whole CD unit, remove the main CD board for access, remove the CD
subchassis, replace the pickup, re-assembly, etc. The cost of a KSS pickup
isn't too bad from some suppliers, but from Aiwa or Sony could be
cost-prohibitive. so the OP would need to hunt down a generic
distributor.... The list of caveats for the OP gets longer and longer the
more I consider the issue.
Considering the class of the Aiwa in question, I say just tweak the pot a
bit and run her 'til she dies, which could easily be a couple more years.

Mark Z.

 

[Sam Goldwasser]

He had a soon to be 19 year old combo that's been sitting in the closet
for almost 8 years. No harm in tinkering with the laser pot.

Yes there is. If he had blown the laser, it wouldn't have been obvious
as there would still probably be some indication of light from it and he would
then spend 3 more days trying to fix a problem which at that point was
hopeless without a new pickup.

If the laser output has to be turned up, it probably means that there is
a loss of signal somewhere else due to dirty optics or some other cause.
The lsaer power is regulated by optical feedback inside the laser diode
package and that will try to maintain the same output power until the
laser itself is no longer able to provide it, regardless of current.

--- sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/
Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
+Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm
| Mirror Sites: http://www.repairfaq.org/REPAIR/F_mirror.html

Important: Anything sent to the email address in the message header above is
ignored unless my full name AND either lasers or electronics is included in the
subject line. Or, you can contact me via the Feedback Form in the FAQs.

 

[Arfa Daily]

Yes there is. If he had blown the laser, it wouldn't have been obvious
as there would still probably be some indication of light from it and he
would
then spend 3 more days trying to fix a problem which at that point was
hopeless without a new pickup.

If the laser output has to be turned up, it probably means that there is
a loss of signal somewhere else due to dirty optics or some other cause.
The lsaer power is regulated by optical feedback inside the laser diode
package and that will try to maintain the same output power until the
laser itself is no longer able to provide it, regardless of current.

--- sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/

Yes Sam, agreed. That is the point exactly. I did say that I was pleased for
the OP that he had got his CD player working in this way, but the point that
I took issue with was that this should be offered to others on the group as
general good advice, and a first thing to try if cleaning did not cure the
problem. KSS series lasers are cheap - even from Sony / Aiwa, and the
generics are almost cheaper than the postage from many suppliers. Most of
the Aiwa models, if you are used to working on them, can have their lasers
replaced from the top, without having to dismantle all the bottom end, but
even if you prefer to do it the 'long' way, it is but a few minutes extra
work. I stand by my original contention that in the professional repair
field, laser adjustment, except as I have detailed for the likes of Pioneer,
should not be considered an option unless you have properly explored all
other potential causes of the problem, and feel that you really must have a
tweak to try and prove a low output laser to yourself. Having proved such,
the laser should then be replaced, not left turned up. Amateur repairers,
who have no 'feel' for carrying out such adjustments, should not attempt
them, as they might wreck a previously functional laser that was not
responsible for the original problem.

Arfa

 

[Meat Plow]

Yes there is. If he had blown the laser, it wouldn't have been obvious
as there would still probably be some indication of light from it and he would
then spend 3 more days trying to fix a problem which at that point was
hopeless without a new pickup.
If the laser output has to be turned up, it probably means that there is
a loss of signal somewhere else due to dirty optics or some other cause.
The lsaer power is regulated by optical feedback inside the laser diode
package and that will try to maintain the same output power until the
laser itself is no longer able to provide it, regardless of current.

My reply was based upon that If the OP was smart enough to tweak the pot
he's obviously smart enough to return it if and when he replaced the
laser.

 

[Meat Plow]

The OP said 1998, not 1988...

Need to clean my glasses.

I have no problem with a slight adjustment to get it going if cleaning
fails. In my experience the laser diode has a range if operating current
within which it's OK. Every cd player laser circuit has an APC circuit to
maintain diode current. As the laser weakens, the circuit juices it up some
anyway.
The OP's solution isn't perfect, to be sure - but the only alternative is to
replace the laser, which actually is a LOT more disassembly to remove the
whole CD unit, remove the main CD board for access, remove the CD
subchassis, replace the pickup, re-assembly, etc. The cost of a KSS pickup
isn't too bad from some suppliers, but from Aiwa or Sony could be
cost-prohibitive. so the OP would need to hunt down a generic
distributor.... The list of caveats for the OP gets longer and longer the
more I consider the issue.
Considering the class of the Aiwa in question, I say just tweak the pot a
bit and run her 'til she dies, which could easily be a couple more years.

Mark Z.

Exactly my thoughts. It's not like it's a high end $1000.00 player or a
repair for a customer as it was the OP's own unit. Bump the pot and maybe
get another year or better out of it. After that if you want to fix it
right replace the optics and recal.

 

[Meat Plow]

Yes Sam, agreed. That is the point exactly. I did say that I was pleased for
the OP that he had got his CD player working in this way, but the point that
I took issue with was that this should be offered to others on the group as
general good advice, and a first thing to try if cleaning did not cure the
problem. KSS series lasers are cheap - even from Sony / Aiwa, and the
generics are almost cheaper than the postage from many suppliers. Most of
the Aiwa models, if you are used to working on them, can have their lasers
replaced from the top, without having to dismantle all the bottom end, but
even if you prefer to do it the 'long' way, it is but a few minutes extra
work. I stand by my original contention that in the professional repair
field, laser adjustment, except as I have detailed for the likes of Pioneer,
should not be considered an option unless you have properly explored all
other potential causes of the problem, and feel that you really must have a
tweak to try and prove a low output laser to yourself. Having proved such,
the laser should then be replaced, not left turned up. Amateur repairers,
who have no 'feel' for carrying out such adjustments, should not attempt
them, as they might wreck a previously functional laser that was not
responsible for the original problem.

Arfa

He disclaimered his kludge with "do it at your own risk" that was good
enough warning for me.

 

[Geoffrey S. Mendelson]

He disclaimered his kludge with "do it at your own risk" that was good
enough warning for me.

I've found that tweaking up the laser power on the "too cheap to fix"
DVD players made in Eastern Europe get a few more months life out of them.

It's better than nothing. There are no parts available for them, and
even if they were, they cost less than the shop time to fix them.

I gave up and took an old computer, a video card with a TV out,
a standard DVD-ROM drive and an old remote control, added in MythTV,
and got a DVD and almost anything else player. Sometime's it's anoying,
and the setup was not really easy, but it works, and keeps working.

Geoff.

 

[Meat Plow]

I've found that tweaking up the laser power on the "too cheap to fix"
DVD players made in Eastern Europe get a few more months life out of them.

It's better than nothing. There are no parts available for them, and
even if they were, they cost less than the shop time to fix them.

That's another point.

 

[aasdf]

Thanks for the replies guys. Didn't realize this would generate so
much controversy. I'm just a shmo who had a piece of equipment he
thought wasn't ever going to work again, and certainly wasn't willing
to pay half the purchase price to get it fixed. I definitely am not an
engineer nor would I recommend any electronic repairman do what I did.
But I didn't have any fancy gadgets that you mention to analyze the
system, I just had a philips head screwdriver. I don't even know what
that pot does! I assume it turns up the power of the laser. But I was
just thrilled it worked at all that I figured I'd put it here for
anybody who is my situation. It was a little project to distract
myself from studying for finals

Keep up the good work and thanks for the informative replies!

aasdf

 

[Arfa Daily]

Thanks for the replies guys. Didn't realize this would generate so
much controversy. I'm just a shmo who had a piece of equipment he
thought wasn't ever going to work again, and certainly wasn't willing
to pay half the purchase price to get it fixed. I definitely am not an
engineer nor would I recommend any electronic repairman do what I did.
But I didn't have any fancy gadgets that you mention to analyze the
system, I just had a philips head screwdriver. I don't even know what
that pot does! I assume it turns up the power of the laser. But I was
just thrilled it worked at all that I figured I'd put it here for
anybody who is my situation. It was a little project to distract
myself from studying for finals

Keep up the good work and thanks for the informative replies!

aasdf

No problem ! Made for a lively and interesting debate anyway. Good luck with
the finals, and as I said, glad the solution worked for you.

Arfa

 

[Meat Plow]

Thanks for the replies guys. Didn't realize this would generate so
much controversy. I'm just a shmo who had a piece of equipment he
thought wasn't ever going to work again, and certainly wasn't willing
to pay half the purchase price to get it fixed. I definitely am not an
engineer nor would I recommend any electronic repairman do what I did.
But I didn't have any fancy gadgets that you mention to analyze the
system, I just had a philips head screwdriver. I don't even know what
that pot does! I assume it turns up the power of the laser. But I was
just thrilled it worked at all that I figured I'd put it here for
anybody who is my situation. It was a little project to distract
myself from studying for finals

Keep up the good work and thanks for the informative replies!

aasdf

LOL some of these guys get a little over zealous. I knew from your initial
post that you really had nothing to lose by what you did. And I support
tinkerers and experimenters in the right situations. I'm self taught
myself. 51 yrs old that soldered his first joint back in 1969 when I was
taken in by a hobbiest and taught the rudimentary skills. I've done
factory service for a whole slew of brand names since then. I specialize
now in professional audio, mostly high wattage solid state power amps and
tube amps.

 

[Arfa Daily]

LOL some of these guys get a little over zealous. I knew from your initial
post that you really had nothing to lose by what you did. And I support
tinkerers and experimenters in the right situations. I'm self taught
myself. 51 yrs old that soldered his first joint back in 1969 when I was
taken in by a hobbiest and taught the rudimentary skills. I've done
factory service for a whole slew of brand names since then. I specialize
now in professional audio, mostly high wattage solid state power amps and
tube amps.

I know what you're saying Meat, but I think you are missing the point of
what I was saying. Any of us on here that are professionally involved in
electronics service, could see the post and the poster for what it was, and
I really didn't have a problem with him getting his (old) unit going by
tweaking the pot - we've all done it. But by the same token, there are other
amateurs that come on here to learn, and if they are going to do that, they
might as well learn properly, as I am sure that you have done over the years
after your hobbyist start. No one would advocate twiddling with pots that
you don't even know what they do, and in the case of a laser power pot, it
is one of the surest ways to compound whatever the original problem was.
That was all I was trying to say for the benefit of learners who wanted the
professional take on whether or not it was a good idea to attack this pot as
a means of diagnosing a bad laser. Just as a matter of interest, we're about
the same age so have come through the rapid advancement of microelectronics
together. I don't know about you, but I find it harder and harder to keep up
as the years roll by. I don't know whether its that the technology is
advancing so fast, or whether I've lost the enthusiasm of youth, but I seem
to find myself just not wanting to be bothered with it all any more. Was the
time when I read nothing but technical journals. These days, I get more out
of reading the newspaper ... ;~)

Arfa

 

[Meat Plow]

I know what you're saying Meat, but I think you are missing the point of
what I was saying. Any of us on here that are professionally involved in
electronics service, could see the post and the poster for what it was, and
I really didn't have a problem with him getting his (old) unit going by
tweaking the pot - we've all done it. But by the same token, there are other
amateurs that come on here to learn, and if they are going to do that, they
might as well learn properly, as I am sure that you have done over the years
after your hobbyist start. No one would advocate twiddling with pots that
you don't even know what they do, and in the case of a laser power pot, it
is one of the surest ways to compound whatever the original problem was.
That was all I was trying to say for the benefit of learners who wanted the
professional take on whether or not it was a good idea to attack this pot as
a means of diagnosing a bad laser. Just as a matter of interest, we're about
the same age so have come through the rapid advancement of microelectronics
together. I don't know about you, but I find it harder and harder to keep up
as the years roll by. I don't know whether its that the technology is
advancing so fast, or whether I've lost the enthusiasm of youth, but I seem
to find myself just not wanting to be bothered with it all any more. Was the
time when I read nothing but technical journals. These days, I get more out
of reading the newspaper ... ;~)

Arfa

My Panasonic PT51 was the first advanced deviced I've worked on in awhile.
Still haven't got the left side converge tweaked (guess I need to go copy
the service manual for instructions on the service man mode since nobody
chimed in here) I'm out of the current tech loop and that's why I stick to
the stuff I know like SS and tube amps (pro audio). I along with siblings
own a music store so there is no shortage of repairs. I'm also a ham radio
operator for 17 years and work on rf power amps and blocks. I guess my
favorite things to repair employ tubes and I'm an avid tube audio buff.
I always enjoy reading your posts and can tell you are very savvy in the
industry and you do always mean well. Take care.

 

[N Cook]

I know what you're saying Meat, but I think you are missing the point of
what I was saying. Any of us on here that are professionally involved in
electronics service, could see the post and the poster for what it was, and
I really didn't have a problem with him getting his (old) unit going by
tweaking the pot - we've all done it. But by the same token, there are other
amateurs that come on here to learn, and if they are going to do that, they
might as well learn properly, as I am sure that you have done over the years
after your hobbyist start. No one would advocate twiddling with pots that
you don't even know what they do, and in the case of a laser power pot, it
is one of the surest ways to compound whatever the original problem was.
That was all I was trying to say for the benefit of learners who wanted the
professional take on whether or not it was a good idea to attack this pot as
a means of diagnosing a bad laser. Just as a matter of interest, we're about
the same age so have come through the rapid advancement of microelectronics
together. I don't know about you, but I find it harder and harder to keep up
as the years roll by. I don't know whether its that the technology is
advancing so fast, or whether I've lost the enthusiasm of youth, but I seem
to find myself just not wanting to be bothered with it all any more. Was the
time when I read nothing but technical journals. These days, I get more out
of reading the newspaper ... ;~)

Arfa

There was a time when I used to regularly buy ETI and Wireless World, then
only looking at them occassionally in a library and then not even that.
First time for years I looked at one in the library recently , forget which
mag, but all it had in it was Spice modelling, or similar simulations, and
not one bit of hands-on anything