Denon UD-M30 - repair or replace?

[Clive D]

For the OP, be aware that Denon will be introducing the DM40 shortly, the DM39 - which is a great machine and problem free in my kitchen - might be available at a lowered price.

 

[rtrt]

Please do not use a Q-tip and isopropyl alcohol, that is the lamest thing to use on the Laser upper Optic, first of all a Q-tip will scratch the plastic lens alcohol will fog the plastic. Use a piece of sheep skin or a micro fiber cloth with just a little Windex to clean the outer Plastic Optic Lens and lightly shoot can air in to the laser optic assembly to remove any dust after cleaning the Laser optic lens, remember People 92% of the laser optics are plastic and plastic scratches very easily, plus I am, a real, Audio-Video Technician and been repairing Electronics for 40+ years. Thanks.

Hi Supertech hope you don't mind me asking your advice on my old cd player. Its a Pioneer pd8500 and I'm keen to get using it again.

I've recently fixed one major problem, but am left with a more subtle one. The positive is that I've fixed the skipping forward that happened on track 1 of every disc - turns out that the laser sled was binding on a piece of plastic that had come unglued in the mech.

However having fixed that, i have the more subtle issue where on the first play of a disc, about 10-20 seconds in to the first song, there's a sub 1 second no sound period. i don't hear the laser skip and looking at the time on the display there's no skip fwd or back. If I then go back to the start of the song the no sound problem doesn't repeat - suggesting that it's nothing to do with the laser position, except maybe on the first time through only?

I have the maintenance manual, where the exploded diagram helped with the mechanical issue above. I've tried putting the player into test mode and run it through the steps in the manual, but I suspect without the test disc and tools - Oscilloscope etc I'm probably not going to achieve much there.

If you have any suggestions for a next step that'd be much appreciated.

Apologies to the OP for the hijack, but it is old...

 

[mickyricky]

I have a Denon m30 which has started playing up, it goes max volume on switch on and you have to rush to it to turn it down....
Any help on fixing the problem will be appreciated..

 

[Almca]

From memory....unscrew the screws marked red + the cables marked red in the picture & that pcb will "flip" from right to left revealing the lense.

I'll open mine up tomorrow to confirm, its been a while !

Am trying to access the lense on my UD M30. Istari_knight left this helpful note but the attached picture is no longer available. Could you repost the picture or could someone point the way to simply accessing the lense for cleaning?
Can it be cleaned without dismantling teh casing?

 

[peter bj]

Perhaps buying the same used would be cheaper and save a lot of faffing about usually plenty about

 

[Almca]

It's a thought although checking on line a lot of machines seem to have faults.

 

[Minstrel SE]

These mini boxes are rarely worth repairing.

Theres usually some built in obsolesence and they just dont seem to last long.

Denon are a good brand but mini units are built to a price including a large chunk of vat. The cd mechanism is cheap and not reliable over long periods. Too much going on in a small box.

Ive seen units from Teac and Sharp which are ready for the skip after less than a couple of years. Its simply not cost effective to repair them even if the parts are available.

Without the right diagnostic tools most of us wont achieve much. I think weve got to realise that mini systems are a budget option with a short lifespan. Nobody is really going to pay a service engineer or spend too much effort on them.

 

[Lee T]

If it were me I'd go for one of these:

http://www.froogle.richersounds.com/product/mini-hifi/denon/dm39/deno-dm39-sil

That's a cracking price at the moment and will give you various features you don't get on your existing unit. You can use it with your existing speakers.

Oh and no, I don't work for Richer Sounds!

I agree, having owned both this really does outshine the 31 on every level, you will not want to have the 31 repaired or replaced i feel if you purchased this.

Even the earlier dm38 sounds far superior to the 31 & can be purchased for very little these days.

http://rover.ebay.com/rover/1/710-5...0001&campid=5338728743&icep_item=252125446065

http://rover.ebay.com/rover/1/710-5...0001&campid=5338728743&icep_item=252148986286

 

[cj66]

I have a Teac PD-H300 with similar problems. I have cleaned the laser which made a minor improvement but was wandering if a similar reset code existed for this model?

(I have downloaded a version of the service manual in which there are no service codes)

Thanks

 

[DrewR]

I have, sadly, come to this quite late and I hope the original participants are still about.

I bought the whole system, which included the Mission speakers and the tape player/recorder, for my daughter when she became a student. I got feedback that it was not as happy as it should have been but no detail.

It was handed back a few months ago with the declaration that it is c**p and had been since it was only a few months old. Seems it is the same old problems: CDs would not play properly, the volume would be all over the place and the manual might as well be in Sanskrit.

I am resolved to try to fix it but have fallen at the first fence; i.e. getting the case off. It seems to be connected to the fascia at the top but I cannot see how to get it free. Clearly everyone here has managed it so I am feeling that I must be being a bit dim. Any suggestions or hints would be much appreciated.

 

[DM30]

I have tried the calibration procedure but can't seem to get it to work so I must be doing something wrong.

How long do i need to hold the power and function buttons? What exactly does press play 3 times at 3 second intervals mean? Do I press play a total of 9 times, or 3 times with three seconds between presses? Thanks!

 

[ABPC]

Admittedly this is a very old thread, but it’s one I found while trying to fix mine. The problem was identical to the OP. I have a solution.

basically, this non read error in my player was caused because the tray fails to lift the cd upwards at the end of the load. So the disk is never even read. Why?

Well the lifting mechanism is powered by the same motor that moves the cd tray in out. They share the same cam. However, lifting the cd off the tray requires slightly more torque on the motor. As such, the silicone band connecting motor and pulley has gone slightly loose and my guess is, it was slipping on a higher load. It will still move the CD tray no problem - which is why it’s a confusing issue. In short, all I needed to do was put a new band on the pulleys and it works great. Reads cds every time.

I did clean the laser, and re- lubricated the the mechanism. But it’s the little rubber band that’s the issue. I suspect with the original poster, the CD player being in the kitchen, the heat has caused the band to sag?? Maybe. Anyway, this was my fix and it was super easy to do one discovered.

 

[linnfomaniac83]

Admittedly this is a very old thread, but it’s one I found while trying to fix mine. The problem was identical to the OP. I have a solution.

basically, this non read error in my player was caused because the tray fails to lift the cd upwards at the end of the load. So the disk is never even read. Why?

Well the lifting mechanism is powered by the same motor that moves the cd tray in out. They share the same cam. However, lifting the cd off the tray requires slightly more torque on the motor. As such, the silicone band connecting motor and pulley has gone slightly loose and my guess is, it was slipping on a higher load. It will still move the CD tray no problem - which is why it’s a confusing issue. In short, all I needed to do was put a new band on the pulleys and it works great. Reads cds every time.

I did clean the laser, and re- lubricated the the mechanism. But it’s the little rubber band that’s the issue. I suspect with the original poster, the CD player being in the kitchen, the heat has caused the band to sag?? Maybe. Anyway, this was my fix and it was super easy to do one discovered.

Excellent, people always jump to the conclusion that it’s the laser, but there are any number of reasons why a CD player may fail to read TOC, sometimes it is the laser, they do lose emission over time, but it can just as easily be a mechanical issue or an electrical issue elsewhere, capacitors in the PSU or servo can fail, and in something as sensitive as a CD player, ripple can and does cause read issues… I’ve repaired many Linn CD players and fewer than 50% have required a new laser, (red book machines, not the Unidisk machines, the lasers are sh!te in those), I’ve replaced motors, belts, caps and voltage regulators to revive them.

 

[EkkiU]

Hi everyone.

I'm afraid I only post here when I have a problem and today is no exception!

I have a Denon UD-M30 CD/receiver as a second system in the bedroom, with the matching SCM51 Denon/Mission speakers in the bedroom and a pair of Eltax Mirage 2i speakers run into the adjacent kitchen.

It gets plenty of use, especially when my wife is cooking, but the CD player is getting increasing problematic. More often that not, it cannot read CDs and shows the track count as zero. If it is turned off/on enough or the CD ejected and reinserted multiple times, it might eventually read the CD contents properly - once this happens the CD will normally play ok. However, once the disk is ejected and another put in, the problem starts again.

This has gradually been getting worse over the last year and my wife has finally lost patience with it so I need to do something before she loses patience with me as well.

So my questions are:

(a) Is it worth trying to repair it? Does it use a commonly available CD transport?
(b) Is there a well rated CD receiver on the market which would be a good replacement with the existing speakers?

I would be grateful for any comments. I got the UD-M30 almost 10 years ago so I am a bit out of touch with what is available now.


Thanks.

Hi all those who contributed to that thread. Of today I can confirm that obviously the rubber belt driving the disc eject system is the culprit of most of the troubles described. In oder to get to the belt (after opening the chassis following the example

) you only have to disconnect the wiring that runs atop the disc unit to the right of the main body, which allows you enough wriggling space to remove the belt. As already mentioned along the thread, a similarly sized rubber band does the trick - temporarily at least - and leaves oneself in awe that such a cheap operation might result in another decade of audio pleasure.

Thank you all for your comments and encouragement.