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Hacking a Denon RCD M35DAB, CD of 2006, so far so good

N

N_Cook

Jan 1, 1970
0
Neither me or owner will spend out on a new optical unit (failed laser),
big spondulics. But a near industry standard KSS 213C looked somewhat
similar , so I tried it out. This one laying around , unknown condition,
from some scrapped something. The ribbon feed lines for the 3 laser pins
matched , the other 2 deck motor+switch leads matched up, so tried it
out. Laser lit but logic of the end stops wrong so swapped the optical
unit across to the original (scrapper would not have mechanically fitted
in the Denon anyway). Required some bodging to fit, straightforward but
too much for detailing here, but sledge etc worked .
Adjusted power pot and cleaned lens and now consistently reads data
track and plays about first 2 minutes track1 of any CD I try, faulters
and stops, will not play any track 2 or higher.
I suspect the registration of the centre limit switch is out, but could
be a problem with the rack although powers up and down the slide without
incident with only 2 volt on the motor, but I will try marking rack and
cog of the 2minute stoppages. I assume a new (cheap) KSS 213 would show
the same stoppage.
So how to adjust the end stop , ? pieces of shim material added and
subtracted in the gap between sledge and leaf switch and suck it and
see? or some other problem likely?
 
M

Mark Zacharias

Jan 1, 1970
0
N_Cook said:
Neither me or owner will spend out on a new optical unit (failed laser),
big spondulics. But a near industry standard KSS 213C looked somewhat
similar , so I tried it out. This one laying around , unknown condition,
from some scrapped something. The ribbon feed lines for the 3 laser pins
matched , the other 2 deck motor+switch leads matched up, so tried it out.
Laser lit but logic of the end stops wrong so swapped the optical unit
across to the original (scrapper would not have mechanically fitted in the
Denon anyway). Required some bodging to fit, straightforward but too much
for detailing here, but sledge etc worked .
Adjusted power pot and cleaned lens and now consistently reads data track
and plays about first 2 minutes track1 of any CD I try, faulters and
stops, will not play any track 2 or higher.
I suspect the registration of the centre limit switch is out, but could be
a problem with the rack although powers up and down the slide without
incident with only 2 volt on the motor, but I will try marking rack and
cog of the 2minute stoppages. I assume a new (cheap) KSS 213 would show
the same stoppage.
So how to adjust the end stop , ? pieces of shim material added and
subtracted in the gap between sledge and leaf switch and suck it and see?
or some other problem likely?


I think this is a sled motor issue; I have never seen any limit switch other
than the inner (start) switch. As the tracking coil reaches it's physical
limit, a player will skip or "falter and stop" just like you describe, if
the sled does not advance.Check the voltage across the sled motor as this
process unfolds. At some point the voltage should increase to kick the sled
forward. Maybe there's a mechanical obstruction, maybe you still have wiring
issues.

Mark Z.
 
N

N_Cook

Jan 1, 1970
0
I would agree with everything that Mark says. The lens tracks across the
disc with a sort of 'wave' motion, the 'fine' part of this process being
handled by the lens tracking coils, and the 'coarse' part by the sled
motor and associated gearing. The time between motor 'roll-ons' varies
from player to player, but is typically between about 4 and 10 seconds.
If you monitor the voltage across the motor during each period, you will
see it ramp up gently until the point is reached where the motor rolls
over one or two commutator segments. If all is well with the servo, the
motor and the mechanics, there should be no overshoot, but often there
is, and the motor will roll back a little. When I am looking for this
specific problem, I always mark some radial lines on the large top-side
drive gear with a Sharpie pen. You can then watch the behaviour of the
coarse tracking operation, doing a rough count between roll-ons. If you
see the time varying a lot, there is usually a mechanical problem with
either the motor or gear train. If you see it taking a long time to roll
on round about where you are expecting it to give trouble, you can try
helping it along by giving the gear a gentle poke in the direction it
should move. If that keeps it playing, then there you go. Maybe the sled
motor on the original deck is poor. You could always try the old trick
of squirting a drop of switch cleaner in the holes at the back, and then
'blasting' it very briefly several times in each direction with 12
volts. That will usually clean up the comm and brush gear enough to get
it running smoothly again, proving the point that you need to replace
the motor.

You might also check the performance of the spindle motor, as this can
also cause tracking problems if it produces enough data jitter. Also,
try selecting a track well into the disc, before pressing play, and see
if it goes there ok and plays through the track, or gives trouble again
a couple of minutes in. 'Lumpy' spindle motors tend to behave better on
later tracks where the rotation speed is less. Looking at the eye
pattern on a scope can tell you a lot about tracking and jitter
behaviour. The same 'clean it and blast it' technique can also be used
on spindle motors to temporarily recover them to prove the point

Arfa

I changed the position of the central limit switch action point by 1.2mm
and the same play for 2 mins only.
The Denon optical unit , marked Sanyo, does not use the usual
double-rack anti-backlash arrangement but a much cruder sort of sprung
plastic arm tensioner via the mount of the final double cog. I had to
remove the second rack on the KSS213 to fit in the available space. The
tension is now too high, the rack must be .5mm or so wider, and I'll
have to find a way of backing off the tension. The final cog to the rack
is 12 teeth and I can feel resistance 12 times a rev. Running the motor
continuously , even at low V,the inertia overcomes that lumpiness, but
that is not representative of the normal radial stepping drive, as you say.
 
M

Mark Zacharias

Jan 1, 1970
0
N_Cook said:
I changed the position of the central limit switch action point by 1.2mm
and the same play for 2 mins only.
The Denon optical unit , marked Sanyo, does not use the usual double-rack
anti-backlash arrangement but a much cruder sort of sprung plastic arm
tensioner via the mount of the final double cog. I had to remove the
second rack on the KSS213 to fit in the available space. The tension is
now too high, the rack must be .5mm or so wider, and I'll have to find a
way of backing off the tension. The final cog to the rack is 12 teeth and
I can feel resistance 12 times a rev. Running the motor continuously ,
even at low V,the inertia overcomes that lumpiness, but that is not
representative of the normal radial stepping drive, as you say.

I guess I kind of missed the point of replacing a Sanyo laser with a used
Sony.

Bad idea - be surprised if you ever get it to work right, at least with any
acceptable combination of parts cost and time/effort.

'nuff said.

Mark Z.
 
N

N_Cook

Jan 1, 1970
0
Nope. When did you send it ? To arfa{dot}daily{at}ntlworld{dot}com yes
? That address definitely works ok. I have received at least five mails
on it today, and have just sent myself one from another address, and it
was delivered immediately.

Arfa

Talk about illogical, machine readable valid em address you deliberately
don/t spoof in usenet headers but spoofed em address in the body.
 
N

N_Cook

Jan 1, 1970
0
What a pillock, the racks are 2 different pitches , the KSS213C one
something like 21 teeth per 20mm and the Denon one is a bit coarser, I
assumed that all such racks were the same. Whether the final cog will
swap over,and tooth pitch mismatch betwwen cog and cograther than cog
and rack, will find out later
 
N

N_Cook

Jan 1, 1970
0
I guess I kind of missed the point of replacing a Sanyo laser with a
used Sony.

Bad idea - be surprised if you ever get it to work right, at least with
any acceptable combination of parts cost and time/effort.

'nuff said.

Mark Z.

The Denon optical unit is labelled CD11FTA3N , unless you are aware of
its Sanyo number , they are expensive to replace, presumably specials
produced by Sanyo and consequential markup.
 
N

N_Cook

Jan 1, 1970
0
I melded together a 1.25mm pitch cog with a 0.95mm one with only about
..2mm ecentricity but much the same result.
I've now noticed why pre-selecting track 2 or 5 or whatever results in
no play. The sledge is propelled to the periphery as though track 10 was
selected, so something wrong in the interpretation of "0" track data ?
or something beyond any resolution by me unless anyone has any insight?
 
C

chuck

Jan 1, 1970
0
CD11FTA3N


The cheapest I found one for is $89.00 U.S. with free shipping. That's
cheaper than hours of labor trying to make incompatible parts work.
Chuck
 
N

N_Cook

Jan 1, 1970
0
The cheapest I found one for is $89.00 U.S. with free shipping. That's
cheaper than hours of labor trying to make incompatible parts work.
Chuck

The cheapest I found in the UK was , with all the usual extras about 90
pounds. Much more interesting playing around/hacking. No guarantee that
there is not some sort of random ps or other surge that knocked out the
original laser and could equally do the same with a 90 quid replacement
 
M

Mark Zacharias

Jan 1, 1970
0
N_Cook said:
The cheapest I found in the UK was , with all the usual extras about 90
pounds. Much more interesting playing around/hacking. No guarantee that
there is not some sort of random ps or other surge that knocked out the
original laser and could equally do the same with a 90 quid replacement


You could try just looking at various Sanyo pickups on eBay and probably
find it there under the SFP or whatever number.

Mark Z.
 
N

N_Cook

Jan 1, 1970
0
the usual extras about 90 pounds. Much more interesting playing
around/hacking. No guarantee that there is not some sort of random ps or
other surge that knocked out the original laser and co

The number on the Denon Sanyo one is SF-P101N but as that is on the
plastic of the body rather than a label, there may be a lot of flavours.
The optical unit just carries the laser , the receive photodiode matrix
, and the focus+track coils. Could the track coil polarity be wrong?
2 minutes in could be where the sledge has to definitely have moved as
come to the limit of the coil shift ambit, worth a try . Now what
differentiates the orthogonal coils? A small voltage in each to see if
the lens moves vertically or radially I suppose. Nothing like
heuristics, its not as though the owner is paying for my farting about.
 
N

N_Cook

Jan 1, 1970
0
Same 2V polarity on lines 1 and 4 of the ribbon send the focus the same
way and same for lines 2 and 3 for the track throw for both optical
blocks, so nowhere left to go
 
N

N_Cook

Jan 1, 1970
0
The SM (listed RCD M33DAB) has the test mode details. May as well try it
as does not seem to require a test CD. although at no stage has it
registered one of the 20 listed error codes
 
N

N_Cook

Jan 1, 1970
0
Errr, I'm not getting this. The SF-P101N is a well-known Sanyo laser,
and available - even as a complete sub-deck - for just a few quid -
literally ...

You are slightly correct in there being more than one flavour. There are
in fact two. One has a 15 pin connector, and the other, a 16 pin. This
is always detailed where they are offered for sale, so there should be
no issue getting the right one.

http://www.ebay.co.uk/itm/Optical-L...ther_Computing_Networking&hash=item3383bb1e50


http://www.ebay.co.uk/itm/SANYO-CD-...al_Components_Supplies_ET&hash=item3a5e6e9d65


http://www.ebay.co.uk/itm/SF-P101N-...?pt=UK_Sound_Vision_Other&hash=item416ed6a41e


http://www.ebay.co.uk/itm/SF-P101N-...?pt=UK_Sound_Vision_Other&hash=item51a83d29c3


Arfa

In the meantime
It all seems mighty weird that you can progress flawlessly through the
test routines along with never any error statements but the unit does
not work.
Test routines pass byte info out on focus balance, focus gain,track
balance , track gain , focus offset , track offset,RFRP and a routine
that sums errors in a 2 second sample. Go into the auto adjust routine
after adjusting the power pot and the values change. I don't know what
100% error figures for 2 seconds would be ,but readings about 023,000
one time then adjust pot and then average about 035,000. So if 6 digits
is 100% then about 2 to 4 percent. What would a representative figure be
for dust,microscratches,scatter etc ?
 
M

Mark Zacharias

Jan 1, 1970
0
N_Cook said:
In the meantime
It all seems mighty weird that you can progress flawlessly through the
test routines along with never any error statements but the unit does not
work.
Test routines pass byte info out on focus balance, focus gain,track
balance , track gain , focus offset , track offset,RFRP and a routine that
sums errors in a 2 second sample. Go into the auto adjust routine after
adjusting the power pot and the values change. I don't know what 100%
error figures for 2 seconds would be ,but readings about 023,000 one time
then adjust pot and then average about 035,000. So if 6 digits is 100%
then about 2 to 4 percent. What would a representative figure be for
dust,microscratches,scatter etc ?


You continue to burn large quantities of time on this one. I'd be out of
business in a month if I made a practice of this sort of thing.

My view: Fix the damn thing and get on to the next piece of crap...

Mark Z.
 
N

N_Cook

Jan 1, 1970
0
Sanyo one in there and working all functions. So bulk standard cheapo
with no added Denon flavour it would seem.
BER error now about 100
 
N

N_Cook

Jan 1, 1970
0
Yep. I've replaced quite a few, and never found them to be anything
other than 'standard'. Did you get a whole sub-deck in the end, or just
a laser ?

Arfa

whole deck.
Quite happy with BER of <>100 but I assume this error reading would be a
good monitor , not immediate though, for adjusting the power pot for
optimal.
 
M

Mark Zacharias

Jan 1, 1970
0
N_Cook said:
Sanyo one in there and working all functions. So bulk standard cheapo with
no added Denon flavour it would seem.
BER error now about 100


Finally!

Mark Z.
 
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