Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems.

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Unhappy Denon UD-M50

I have a UD-M50 triple CD player that has given me stirling service until I mistakenly pressed in the CD tray instead of using the button, at which point it jammed.
Having dismantled it I discovered a small problem with the spring that levels the cd tray as it locates into the right position to be read by the lasar. There are two such springs one supporting each side of the tray. This problem I have repaired however I am having trouble setting the positions of the three cd trays with respect to one another in the mechanical changing assembly. I imagine it is just an alignment problem of the trays and gears etc.
I also suspect that it is not an uncommon occurance with this type of equipment.
Can anybody who has come across this problem before please help. I have costed a repair by a professional company and they quote as much as a new item.
Is it necessary to replace the whole cd tray mechanism? or does anyone know how to obtain the necessary alignment instructions. I am pretty sure that there is no significant damage to the unit

Many thanks.
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elfe111
 
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Hi ibbotsnm

have or had the same Problem with my M50

does anyone have an idea how to align those 3 trays?

The most likely way is: tray 3 is in the turntable and the mechanism is
down
tray 2 is above tray 1 - both in the front part of the drawer

these trays have to be bent a lot if you reinsert them into the drawer, so
that the teeth on the one side, do not turn the teeth on the rotating
mechanism or rather move them into an unwanted position. The mechanism is
on that side where the teeth on the trays are.
I have managed to open and close all trays but getting the tray 3 out of
the turntabel still causes problems with tray 2 - hope to solve this by
ading some grease or oil to the mechanism



have luck

Richard

Richard

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Quote:
Originally Posted by elfe111
Hi ibbotsnm

have or had the same Problem with my M50

does anyone have an idea how to align those 3 trays?

The most likely way is: tray 3 is in the turntable and the mechanism is
down
tray 2 is above tray 1 - both in the front part of the drawer

these trays have to be bent a lot if you reinsert them into the drawer, so
that the teeth on the one side, do not turn the teeth on the rotating
mechanism or rather move them into an unwanted position. The mechanism is
on that side where the teeth on the trays are.
I have managed to open and close all trays but getting the tray 3 out of
the turntabel still causes problems with tray 2 - hope to solve this by
ading some grease or oil to the mechanism



have luck

Richard

Richard

Hi Richard

I have obtained the repair manual from a company here in the UK and have recently tried to re-align the trays.
Firstly the manual although helpful in listing the various parts etc.it loses a lot in the translation from Japanese to English. I think you are absolutely correct in your assumption that the trays are arranged. It is probably necessary to fully dismantle the CD assembly from the rest of the unit first before any realistic repairs can be carried out. I have a copy of those instructions if you require one. My problem was that the initial snarl up was because of one of the two spring mechanisms that elevate the disc in the drive position had itself miss-aligned due to a small part of the plastic breaking. This I repaired and after quite some time I managed to understand the 'Carousel' action of the mechanism. By rotating the small bevel gear (the white one that drops loose when the unit is disasembled) 5 complete turns the first tray (Tray 2) is made to traverse from the rear to the front of the unit. Place tray 1 into the rear of the unit and turn the gear a further 5 turns and it should travel from the rear to the front as did the first tray, at the same time the first tray is elevated up to the top front position. the tray will need a little assistance during this operation since it normally works the other way up and relies on gravity to lift (drop) the tray into position. a similar operation is followed by tray 3 so allowing tray 2 to take over the drive position. I also found that the gears didn't rotate fully five times the second time but jammed causing the whole mechanism to foul up. I managed to cure this by disassembling the whole gear mechanism and turning the 'black gears' to a slightly different position from where I was then able to rotate the whole mechanism freely. Although it appeared to work when operated by hand, once I had reassembled the whole unit it refused to operate fully under power. Thats where I stand at the moment. No longer jamming but not yet fully aligned. I will crack the problem yet.!!!

Let me know how you do. I will copy the written procedure if you require it.


regards Norman Ibbotson
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simona2001
 
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Hi Norman and Richard

I'm particularly interested in whether either of you have found a
solution in terms of alignment with the CD trays of the M50 unit.

I'm in the same boat in that the mechanism is out of sync after 2 CDs
were accidently placed in the same tray.

When reassembling the trays I'm guessing right that in the front of the
mech tray 1 is placed above tray 2 and tray 3 resides in the lowered
reading position?

Does the service manual show or describe how the cogs and trays are
positioned for assembly, if you still have a copy of the manual I would
be very grateful if you could email me a copy.

Many thanks!

Simon


--
simona2001
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Arfa Daily
 
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I have a set of alignment diagrams for this deck. It's dead easy once you
know how. It's actually a Sanyo manufactured mech. Before reassembling, ie
putting any trays into the drawer, rotate the whole side gear assembly (
both sides will turn because of the coupling rod across the drawer ) several
turns in both directions, and make sure that this action is completely
smooth. It is quite common for one of the planet gears inside one of the
large gears, to break. This then results in the gears sticking part the way
round.

If you look down on the two ' windows ' on either side of the drawer
topside, you will see the tops of the four gears. If you then rotate the
gears, you will see a line come around. These lines MUST be EXACTLY aligned
side to side ( done by disconnecting the coupling rod, repositioning one
side as required, then reconnecting the rod ), and also front to back on
each side, so all four lines MUST be exactly on top at the same time. This
is the starting point. The drawer is then turned upside down, and tray 2 is
dropped in at the back with the first tooth located over the lower ' catcher
pip ' on the large gear. This position is important. It's also important to
check those teeth on the tray VERY carefully for damage.

Now turn the little bevel gear ( assuming that you haven't lost it !! ) to
the right, gently. The tray will start to be drawn in. Keep your left hand
under it as you wind it in. When it gets to the front, and the lifting
action starts, help it with your left hand fingers pressing up from below.
When it has gone all the way up, stop. Now position tray 1 the same as you
did for tray 2, and wind it in the same way. When it reaches the end, tray 2
should start to retreat, if you keep winding. Rocking back and forth around
this point will give you a good ' feel ' for whether you've got it right.

Now push the white pin on the left underside, towards the front to lift the
disc clamp. Put tray 3 in the back, and let the clamp back down again.

Now slide the gear down the rod on the right side, until it's about half way
down. Now, with the bevel gear in place on the drawer, offer the right side
of the drawer into its groove in the chassis, such that the bevel gear
meshes with the shaft gear, and the claw on the drawer locates over the
shaft. Hinge the drawer down until the left side is resting on top of its
groove. Now, using something very flat like a scalpel blade, push in the
flat white plastic lever which is in the way of the left side going down. If
you're pressing down gently on the left side as you do this, you'll feel
when it gets out of the way. Now withdraw the scalpel, and press down
firmly. The drawer will snap into place with an alarming " crack " ( but
don't be alarmed ... ) And that's it really. It should just work first time.
This mech is also fitted in a Philips model and a Grundig and of course a
Sanyo. I've also seen it, with a different deck fitted, in a DVD player, but
I can't remember what make.

If you need the actual diagrams, mail me direct, and I'll pdf them for you.

Hope this helps

Geoff

"simona2001" m wrote in
message . com...

Hi Norman and Richard

I'm particularly interested in whether either of you have found a
solution in terms of alignment with the CD trays of the M50 unit.

I'm in the same boat in that the mechanism is out of sync after 2 CDs
were accidently placed in the same tray.

When reassembling the trays I'm guessing right that in the front of the
mech tray 1 is placed above tray 2 and tray 3 resides in the lowered
reading position?

Does the service manual show or describe how the cogs and trays are
positioned for assembly, if you still have a copy of the manual I would
be very grateful if you could email me a copy.

Many thanks!

Simon


--
simona2001





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simona2001
 
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Thanks for replying Geoff.

I have followed your instructions but when I reassemble the loading
mech and power on and select a tray to open, tray 1 slides back and I
can hear the motors trying to turn but the mechanism jams and ejects
tray 2, I've never seen the mechanism raise tray 3.

If you could send me a copy of the diagrams I would be very grateful, I
can't see a way of mailing you direct on these forums?

Simon.


--
simona2001
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Location: Dundee, Scotland
Posts: 1
Cool

Quote:
Originally Posted by ibbotsnm
Hi Richard

I have obtained the repair manual from a company here in the UK and have recently tried to re-align the trays.
Firstly the manual although helpful in listing the various parts etc.it loses a lot in the translation from Japanese to English. I think you are absolutely correct in your assumption that the trays are arranged. It is probably necessary to fully dismantle the CD assembly from the rest of the unit first before any realistic repairs can be carried out. I have a copy of those instructions if you require one. My problem was that the initial snarl up was because of one of the two spring mechanisms that elevate the disc in the drive position had itself miss-aligned due to a small part of the plastic breaking. This I repaired and after quite some time I managed to understand the 'Carousel' action of the mechanism. By rotating the small bevel gear (the white one that drops loose when the unit is disasembled) 5 complete turns the first tray (Tray 2) is made to traverse from the rear to the front of the unit. Place tray 1 into the rear of the unit and turn the gear a further 5 turns and it should travel from the rear to the front as did the first tray, at the same time the first tray is elevated up to the top front position. the tray will need a little assistance during this operation since it normally works the other way up and relies on gravity to lift (drop) the tray into position. a similar operation is followed by tray 3 so allowing tray 2 to take over the drive position. I also found that the gears didn't rotate fully five times the second time but jammed causing the whole mechanism to foul up. I managed to cure this by disassembling the whole gear mechanism and turning the 'black gears' to a slightly different position from where I was then able to rotate the whole mechanism freely. Although it appeared to work when operated by hand, once I had reassembled the whole unit it refused to operate fully under power. Thats where I stand at the moment. No longer jamming but not yet fully aligned. I will crack the problem yet.!!!

Let me know how you do. I will copy the written procedure if you require it.


regards Norman Ibbotson
Hi Norman

I have the Denon UD M50. Not having the cd changer problem, but am having a laser problem - it skips for no apparent reason. Have tried various CDs, cleaned them all thoroughly, but it still happens. Just wondered if the repair manual would help. Do you have a link where I could get a copy of the repair manual? Thanks!!

Dave Marshall
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Quote:
Originally Posted by davie_snert
Hi Norman

I have the Denon UD M50. Not having the cd changer problem, but am having a laser problem - it skips for no apparent reason. Have tried various CDs, cleaned them all thoroughly, but it still happens. Just wondered if the repair manual would help. Do you have a link where I could get a copy of the repair manual? Thanks!!

Dave Marshall
Guys
i have just repaired my first Denon m50 ,(thanks to norman ibbotson for emailing me his worksheets)
if you listen you can blasting away in the back ground.
my first attempt failed miserably. 2nd time i was away, where i scored was, before i inserted the first tray after aligned the dots, i check the back end for the marking on the gears (all four)
1st error a swift a disengaging the cross shaft and manually moving the gears to the correct alignment and reinserting the cross shaft careful to keep the gear markings right. i then proceed to insert the trays, the manual only says about two, the general advise previous to this was set tray 3 the rear play position. i carried on turning the gear after inserting tray 3 , tray 2 comes back and tray 1 lifts and tray 3 goes forward.
reassembled as per manual.
when assembled, if you then look on the top you can see the small driving wheel i then proceed to turn this wheel (i think it was clockwise, if the tray moves to the play position then its right) and watch the mechanism work i keep going though a full cycle to ensure the was no jam. i carried on to tray one is in its position ie ready to eject. final check the markings on the gears are correctly aligned. reassembly.
great the tray work perfect, but the cd won't read the disc's, disassemble check movement of lens, great reassmble, still the same, i removed the tray clamp assembly so you can see the laser lens. get a good clean brush (i used a camera lens brush) and gave the lens and the surrounding sensors a good going over, result one happy bunny.

so dave i would suggest you manually cleans the lens, but do not touch the lens with your fingers or use solvents, it can leave grease smears, a clean stiff clean brush is best.
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Default Denon UD-M50



kayal wrote:
davie_snert Wrote:

Hi Norman

I have the Denon UD M50. Not having the cd changer problem, but am
having a laser problem - it skips for no apparent reason. Have tried
various CDs, cleaned them all thoroughly, but it still happens. Just
wondered if the repair manual would help. Do you have a link where I
could get a copy of the repair manual? Thanks!!

Dave Marshall



Guys
i have just repaired my first Denon m50 ,(thanks to norman ibbotson for
emailing me his worksheets)
if you listen you can blasting away in the back ground.
my first attempt failed miserably. 2nd time i was away, where i scored
was, before i inserted the first tray after aligned the dots, i check
the back end for the marking on the gears (all four)
1st error a swift a disengaging the cross shaft and manually moving the
gears to the correct alignment and reinserting the cross shaft careful
to keep the gear markings right. i then proceed to insert the trays,
the manual only says about two, the general advise previous to this was
set tray 3 the rear play position. i carried on turning the gear after
inserting tray 3 , tray 2 comes back and tray 1 lifts and tray 3 goes
forward.
reassembled as per manual.
when assembled, if you then look on the top you can see the small
driving wheel i then proceed to turn this wheel (i think it was
clockwise, if the tray moves to the play position then its right) and
watch the mechanism work i keep going though a full cycle to ensure the
was no jam. i carried on to tray one is in its position ie ready to
eject. final check the markings on the gears are correctly aligned.
reassembly.
great the tray work perfect, but the cd won't read the disc's,
disassemble check movement of lens, great reassmble, still the same, i
removed the tray clamp assembly so you can see the laser lens. get a
good clean brush (i used a camera lens brush) and gave the lens and the
surrounding sensors a good going over, result one happy bunny.

so dave i would suggest you manually cleans the lens, but do not touch
the lens with your fingers or use solvents, it can leave grease smears,
a clean stiff clean brush is best.


Yes keep your fingers and solvents off but do not use a "stiff brush".
The lens mounting is very sensitive and flexible. It would be easy to
damage the linkages that support it if too much force is used. At the
shop where I worked we used a Q Tip, medical grade-wood handle, and with
clean fingers pulled the cotton tip part way off the stick. This gave a
soft but still firm without being hard end. Gently scrub/wipe the lens
in a circular motion. When it's clean you can see a really nice
reflection across the surface of the lens. You might also try blowing
the lens assy with a dusting can, again gently. This will knock out or
dislodge any "big dust bunnies" that might be in the linkage area. Most
PS2's that boot but won't read disks can be fixed with a good lens and
drive sled cleaning. Good luck
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Default Denon UD-M50

Hi

I have a udm50 with draw problems. Is it possible for to send me the alignment diagrams?

Thanks

Peter


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Default Denon UD-M50

I don't have the service manual electronically, but what is the actual problem? I usually have more "fun" getting to the mechanism than repairing it. Most drawer problems are slipping belts. You should be able to replace the belt without losing the alignment. I will check for a procedure for you in the meantime.

Dan
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