DJ Jus

I've got a 6 year old DN-2500F machine which has been working great on one
side for a while now. I suspect the problem with the left hand side of the
player is the spindle motor. The laser / sled / spindle motor actually all
work, but it just won't 'see' any discs. The problem started as as breakups
in the audio on outside tracks. This gradually progressed to inner tracks
and ultimately resulted in the left hand deck not reading any disc at all!

I've read that the CD mechs used by Denon in early machines were made by
Sharp - any ideas what the part numbers of replacement parts are?

I know of a local Denon authorised repairer I can take my machine to, but
I'm not willing to be fleeced if it's something I can fix myself.

Anyone any ideas?

Also a service manual in PDF format (or other) would be fantastic!!!!

DJ Jus

Woohoo!

I found replacement laser assemblies & spindle motors - but on testing my
spindle motor and swapping bits between each side of the deck, have deduced
it's the laser assy that's buggerred :-)

£25 + VAT... not bad. Certainly better than the £100 Denon quoted me.

J.

"DJ Jus" <nomail@nomail.com> wrote in message
news:OsD6b.351$Oc4.177129@newsfep2-gui.server.ntli.net...
> I've got a 6 year old DN-2500F machine which has been working great on one
> side for a while now. I suspect the problem with the left hand side of
the
> player is the spindle motor. The laser / sled / spindle motor actually
all
> work, but it just won't 'see' any discs. The problem started as as
breakups
> in the audio on outside tracks. This gradually progressed to inner tracks
> and ultimately resulted in the left hand deck not reading any disc at all!
>
> I've read that the CD mechs used by Denon in early machines were made by
> Sharp - any ideas what the part numbers of replacement parts are?
>
> I know of a local Denon authorised repairer I can take my machine to, but
> I'm not willing to be fleeced if it's something I can fix myself.
>
> Anyone any ideas?
>
> Also a service manual in PDF format (or other) would be fantastic!!!!
>
>

DJ Jus

Woohoo!

I found replacement laser assemblies & spindle motors - but on testing my
spindle motor and swapping bits between each side of the deck, have deduced
it's the laser assy that's buggerred :-)

£25 + VAT... not bad. Certainly better than the £100 Denon quoted me.

J.

"DJ Jus" <nomail@nomail.com> wrote in message
news:OsD6b.351$Oc4.177129@newsfep2-gui.server.ntli.net...
> I've got a 6 year old DN-2500F machine which has been working great on one
> side for a while now. I suspect the problem with the left hand side of
the
> player is the spindle motor. The laser / sled / spindle motor actually
all
> work, but it just won't 'see' any discs. The problem started as as
breakups
> in the audio on outside tracks. This gradually progressed to inner tracks
> and ultimately resulted in the left hand deck not reading any disc at all!
>
> I've read that the CD mechs used by Denon in early machines were made by
> Sharp - any ideas what the part numbers of replacement parts are?
>
> I know of a local Denon authorised repairer I can take my machine to, but
> I'm not willing to be fleeced if it's something I can fix myself.
>
> Anyone any ideas?
>
> Also a service manual in PDF format (or other) would be fantastic!!!!
>
>

Stig Bronson

The sharp assembly being self-aligning too (more or less)

The older machines had a Sony Mech & Laser which were a bastard to set up.

The failings on the laser unit are rarely real failures. The lens gets dirty
and dust stops the focus mechanics working properly - this then gets
destroyed as the screwdriver experts strip them down and think it's ok to
put pressure on the lens with a cotton bud and alchol.

I'm sure Mr A Hussman can fill us in on the specifics here :-)

"DJ Jus" <nomail@nomail.com> wrote in message
news:ZTH6b.360$Oc4.329579@newsfep2-gui.server.ntli.net...
> Woohoo!
>
> I found replacement laser assemblies & spindle motors - but on testing my
> spindle motor and swapping bits between each side of the deck, have
deduced
> it's the laser assy that's buggerred :-)
>
> £25 + VAT... not bad. Certainly better than the £100 Denon quoted me.
>
> J.
>
> "DJ Jus" <nomail@nomail.com> wrote in message
> news:OsD6b.351$Oc4.177129@newsfep2-gui.server.ntli.net...
> > I've got a 6 year old DN-2500F machine which has been working great on
one
> > side for a while now. I suspect the problem with the left hand side of
> the
> > player is the spindle motor. The laser / sled / spindle motor actually
> all
> > work, but it just won't 'see' any discs. The problem started as as
> breakups
> > in the audio on outside tracks. This gradually progressed to inner
tracks
> > and ultimately resulted in the left hand deck not reading any disc at
all!
> >
> > I've read that the CD mechs used by Denon in early machines were made by
> > Sharp - any ideas what the part numbers of replacement parts are?
> >
> > I know of a local Denon authorised repairer I can take my machine to,
but
> > I'm not willing to be fleeced if it's something I can fix myself.
> >
> > Anyone any ideas?
> >
> > Also a service manual in PDF format (or other) would be fantastic!!!!
> >
> >
>
>

Stig Bronson

The sharp assembly being self-aligning too (more or less)

The older machines had a Sony Mech & Laser which were a bastard to set up.

The failings on the laser unit are rarely real failures. The lens gets dirty
and dust stops the focus mechanics working properly - this then gets
destroyed as the screwdriver experts strip them down and think it's ok to
put pressure on the lens with a cotton bud and alchol.

I'm sure Mr A Hussman can fill us in on the specifics here :-)

"DJ Jus" <nomail@nomail.com> wrote in message
news:ZTH6b.360$Oc4.329579@newsfep2-gui.server.ntli.net...
> Woohoo!
>
> I found replacement laser assemblies & spindle motors - but on testing my
> spindle motor and swapping bits between each side of the deck, have
deduced
> it's the laser assy that's buggerred :-)
>
> £25 + VAT... not bad. Certainly better than the £100 Denon quoted me.
>
> J.
>
> "DJ Jus" <nomail@nomail.com> wrote in message
> news:OsD6b.351$Oc4.177129@newsfep2-gui.server.ntli.net...
> > I've got a 6 year old DN-2500F machine which has been working great on
one
> > side for a while now. I suspect the problem with the left hand side of
> the
> > player is the spindle motor. The laser / sled / spindle motor actually
> all
> > work, but it just won't 'see' any discs. The problem started as as
> breakups
> > in the audio on outside tracks. This gradually progressed to inner
tracks
> > and ultimately resulted in the left hand deck not reading any disc at
all!
> >
> > I've read that the CD mechs used by Denon in early machines were made by
> > Sharp - any ideas what the part numbers of replacement parts are?
> >
> > I know of a local Denon authorised repairer I can take my machine to,
but
> > I'm not willing to be fleeced if it's something I can fix myself.
> >
> > Anyone any ideas?
> >
> > Also a service manual in PDF format (or other) would be fantastic!!!!
> >
> >
>
>

DJ Jus

It's not a dirty lens IMO.

I tested the focus servo etc at work by stripping the deck down with all
cables plugged in and powered the unit on. I had a video camera pointing at
the laser assembly (for eye safety) and looked at it on a colour monitor. I
could clearly see the focus mech moving in & out (trying to focus?), and a
dot of light where you'd expect to see the laser beam.

It's probably not the laser itself which is at fault (see above) but there's
a high possibility that it's the detector diode or mirror that's broken
(both of which are sealed inside the pickup head)... The cause of the fault
might well have been transporting it in the boot of my car, forgetting about
it and leaving it to rattle around for weeks (wooops!).

I hope I'm onto a winner with the new pickup - although I'm slightly
concerned that the deck doesn't spin the disc immediately. I suspect that
it doesn't spin until it's detected a disc by firing the laser and looking
for a reflected signal - if I'm wrong I'll be £21 down and still won't have
fixed my player.

If it's not that, I'll be stumped.
1. it's not the main PCB
2. it's not the cables
3. it's not the PSU
4. it's not the spindle motor
5. it's not the disc table

J.

"Stig Bronson" <spamme@someplace.com> wrote in message
news:QR07b.501$vX3.135940@wards.force9.net...
> The sharp assembly being self-aligning too (more or less)
>
> The older machines had a Sony Mech & Laser which were a bastard to set up.
>
> The failings on the laser unit are rarely real failures. The lens gets
dirty
> and dust stops the focus mechanics working properly - this then gets
> destroyed as the screwdriver experts strip them down and think it's ok to
> put pressure on the lens with a cotton bud and alchol.
>
> I'm sure Mr A Hussman can fill us in on the specifics here :-)
>
> "DJ Jus" <nomail@nomail.com> wrote in message
> news:ZTH6b.360$Oc4.329579@newsfep2-gui.server.ntli.net...
> > Woohoo!
> >
> > I found replacement laser assemblies & spindle motors - but on testing
my
> > spindle motor and swapping bits between each side of the deck, have
> deduced
> > it's the laser assy that's buggerred :-)
> >
> > £25 + VAT... not bad. Certainly better than the £100 Denon quoted me.
> >
> > J.
> >
> > "DJ Jus" <nomail@nomail.com> wrote in message
> > news:OsD6b.351$Oc4.177129@newsfep2-gui.server.ntli.net...
> > > I've got a 6 year old DN-2500F machine which has been working great on
> one
> > > side for a while now. I suspect the problem with the left hand side
of
> > the
> > > player is the spindle motor. The laser / sled / spindle motor
actually
> > all
> > > work, but it just won't 'see' any discs. The problem started as as
> > breakups
> > > in the audio on outside tracks. This gradually progressed to inner
> tracks
> > > and ultimately resulted in the left hand deck not reading any disc at
> all!
> > >
> > > I've read that the CD mechs used by Denon in early machines were made
by
> > > Sharp - any ideas what the part numbers of replacement parts are?
> > >
> > > I know of a local Denon authorised repairer I can take my machine to,
> but
> > > I'm not willing to be fleeced if it's something I can fix myself.
> > >
> > > Anyone any ideas?
> > >
> > > Also a service manual in PDF format (or other) would be fantastic!!!!
> > >
> > >
> >
> >
>
>

DJ Jus

It's not a dirty lens IMO.

I tested the focus servo etc at work by stripping the deck down with all
cables plugged in and powered the unit on. I had a video camera pointing at
the laser assembly (for eye safety) and looked at it on a colour monitor. I
could clearly see the focus mech moving in & out (trying to focus?), and a
dot of light where you'd expect to see the laser beam.

It's probably not the laser itself which is at fault (see above) but there's
a high possibility that it's the detector diode or mirror that's broken
(both of which are sealed inside the pickup head)... The cause of the fault
might well have been transporting it in the boot of my car, forgetting about
it and leaving it to rattle around for weeks (wooops!).

I hope I'm onto a winner with the new pickup - although I'm slightly
concerned that the deck doesn't spin the disc immediately. I suspect that
it doesn't spin until it's detected a disc by firing the laser and looking
for a reflected signal - if I'm wrong I'll be £21 down and still won't have
fixed my player.

If it's not that, I'll be stumped.
1. it's not the main PCB
2. it's not the cables
3. it's not the PSU
4. it's not the spindle motor
5. it's not the disc table

J.

"Stig Bronson" <spamme@someplace.com> wrote in message
news:QR07b.501$vX3.135940@wards.force9.net...
> The sharp assembly being self-aligning too (more or less)
>
> The older machines had a Sony Mech & Laser which were a bastard to set up.
>
> The failings on the laser unit are rarely real failures. The lens gets
dirty
> and dust stops the focus mechanics working properly - this then gets
> destroyed as the screwdriver experts strip them down and think it's ok to
> put pressure on the lens with a cotton bud and alchol.
>
> I'm sure Mr A Hussman can fill us in on the specifics here :-)
>
> "DJ Jus" <nomail@nomail.com> wrote in message
> news:ZTH6b.360$Oc4.329579@newsfep2-gui.server.ntli.net...
> > Woohoo!
> >
> > I found replacement laser assemblies & spindle motors - but on testing
my
> > spindle motor and swapping bits between each side of the deck, have
> deduced
> > it's the laser assy that's buggerred :-)
> >
> > £25 + VAT... not bad. Certainly better than the £100 Denon quoted me.
> >
> > J.
> >
> > "DJ Jus" <nomail@nomail.com> wrote in message
> > news:OsD6b.351$Oc4.177129@newsfep2-gui.server.ntli.net...
> > > I've got a 6 year old DN-2500F machine which has been working great on
> one
> > > side for a while now. I suspect the problem with the left hand side
of
> > the
> > > player is the spindle motor. The laser / sled / spindle motor
actually
> > all
> > > work, but it just won't 'see' any discs. The problem started as as
> > breakups
> > > in the audio on outside tracks. This gradually progressed to inner
> tracks
> > > and ultimately resulted in the left hand deck not reading any disc at
> all!
> > >
> > > I've read that the CD mechs used by Denon in early machines were made
by
> > > Sharp - any ideas what the part numbers of replacement parts are?
> > >
> > > I know of a local Denon authorised repairer I can take my machine to,
> but
> > > I'm not willing to be fleeced if it's something I can fix myself.
> > >
> > > Anyone any ideas?
> > >
> > > Also a service manual in PDF format (or other) would be fantastic!!!!
> > >
> > >
> >
> >
>
>

Stig Bronson

You are probably on the right track and a laser may do it but don't overlook
the two most obvious:>

1> Draw knocks - these flimsy little drawers where ALWAYS getting knocked
and for whatever reason this can totally upset the machines ability to read
a disc

2>PROM going corrupt - these bitches are controlled by software accross a
bus.

3>Corrosion to the PCB - common if the machine has been exposed to large
amounts of synthetic smoke.

I recall the method for putting the machine into service mode was >power
off> hold down both draw open buttons on the unit whilst switching on. You
can then page through the various settings such as laser gain etc. Whilst I
threw the manual away years ago and don't recall what was what - they should
be roughly simular between decks.

Have you tried swapping the mechanisms left to write to prove the main board
is ok?

For the sake of £22 change the pickup - if it clears the fault replace them
both as a good measure and be thankful it was not a 2400 or 2000 MK1 with
Sony Drives :-)

Stig Bronson

You are probably on the right track and a laser may do it but don't overlook
the two most obvious:>

1> Draw knocks - these flimsy little drawers where ALWAYS getting knocked
and for whatever reason this can totally upset the machines ability to read
a disc

2>PROM going corrupt - these bitches are controlled by software accross a
bus.

3>Corrosion to the PCB - common if the machine has been exposed to large
amounts of synthetic smoke.

I recall the method for putting the machine into service mode was >power
off> hold down both draw open buttons on the unit whilst switching on. You
can then page through the various settings such as laser gain etc. Whilst I
threw the manual away years ago and don't recall what was what - they should
be roughly simular between decks.

Have you tried swapping the mechanisms left to write to prove the main board
is ok?

For the sake of £22 change the pickup - if it clears the fault replace them
both as a good measure and be thankful it was not a 2400 or 2000 MK1 with
Sony Drives :-)

DJ Jus

Yeah I swapped everything between them. Deck 1 is the duffer - deck2 works
perfectly & always has.

I removed the player PCB from deck1 & put it on deck2 - worked perfectly. I
put deck 2 in place of deck1 - again worked perfectly. Eventually the only
thing from deck 1 which didn't work in deck2 was the laser assembly.

Not the most efficient fault finding technique, but it worked.

Thanks for the info about common failures though :-) Much appreciated.

J.
"Stig Bronson" <spamme@someplace.com> wrote in message
news:16f7b.719$vX3.181597@wards.force9.net...
> You are probably on the right track and a laser may do it but don't
overlook
> the two most obvious:>
>
> 1> Draw knocks - these flimsy little drawers where ALWAYS getting knocked
> and for whatever reason this can totally upset the machines ability to
read
> a disc
>
> 2>PROM going corrupt - these bitches are controlled by software accross a
> bus.
>
> 3>Corrosion to the PCB - common if the machine has been exposed to large
> amounts of synthetic smoke.
>
> I recall the method for putting the machine into service mode was >power
> off> hold down both draw open buttons on the unit whilst switching on. You
> can then page through the various settings such as laser gain etc. Whilst
I
> threw the manual away years ago and don't recall what was what - they
should
> be roughly simular between decks.
>
> Have you tried swapping the mechanisms left to write to prove the main
board
> is ok?
>
> For the sake of £22 change the pickup - if it clears the fault replace
them
> both as a good measure and be thankful it was not a 2400 or 2000 MK1 with
> Sony Drives :-)
>
>

DJ Jus

Yeah I swapped everything between them. Deck 1 is the duffer - deck2 works
perfectly & always has.

I removed the player PCB from deck1 & put it on deck2 - worked perfectly. I
put deck 2 in place of deck1 - again worked perfectly. Eventually the only
thing from deck 1 which didn't work in deck2 was the laser assembly.

Not the most efficient fault finding technique, but it worked.

Thanks for the info about common failures though :-) Much appreciated.

J.
"Stig Bronson" <spamme@someplace.com> wrote in message
news:16f7b.719$vX3.181597@wards.force9.net...
> You are probably on the right track and a laser may do it but don't
overlook
> the two most obvious:>
>
> 1> Draw knocks - these flimsy little drawers where ALWAYS getting knocked
> and for whatever reason this can totally upset the machines ability to
read
> a disc
>
> 2>PROM going corrupt - these bitches are controlled by software accross a
> bus.
>
> 3>Corrosion to the PCB - common if the machine has been exposed to large
> amounts of synthetic smoke.
>
> I recall the method for putting the machine into service mode was >power
> off> hold down both draw open buttons on the unit whilst switching on. You
> can then page through the various settings such as laser gain etc. Whilst
I
> threw the manual away years ago and don't recall what was what - they
should
> be roughly simular between decks.
>
> Have you tried swapping the mechanisms left to write to prove the main
board
> is ok?
>
> For the sake of £22 change the pickup - if it clears the fault replace
them
> both as a good measure and be thankful it was not a 2400 or 2000 MK1 with
> Sony Drives :-)
>
>