Grahame Posted August 22, 2009 Share Posted August 22, 2009 First off, I'm a lampy not a noise boy, so I'm talking outside of my comfort zone here.... I'm currently using a Denon 650F CD player on a show in the Fringe, and it's suddenly started generating a very irritating static-like click that comes through the system whenever the play/pause button is pressed. Does anyone more familiar with these machines than I am have any idea what's causing this? More importantly, can it be easily fixed? I'm thinking it must be a dirty contact somewhere and that a quick blast of switch cleaner will sort it, but as the play button seems to be directly on the circuit board, I'm not sure if that actually is the problem. Link to comment Share on other sites More sharing options...
KevinE Posted August 22, 2009 Share Posted August 22, 2009 It wont be a dirty contact, and switch cleaner wont help it, they use sealed 6mm tact switches behind those rubber keys which switch a very low level strobed waveform. If the switches fail, they usually either stop responding , or they give a double-click (ie start/pause again) or you just have to press them very hard. As for what it is..no idea, I've serviced alot of these and never seen the problem. I would suspect a logic fault somewhere, maybe in the start buffer, which is buried in an LSI chip. http://i285.photobucket.com/albums/ll55/vendettaberry/IMG_7444.jpg Link to comment Share on other sites More sharing options...
David Duffy Posted August 22, 2009 Share Posted August 22, 2009 I've just checked the official Denon service notes but no mention of this problem. Have you tried other CDs, including stamped (not CD-R) ones to see if the problem is consistent? Link to comment Share on other sites More sharing options...
mutley Posted August 23, 2009 Share Posted August 23, 2009 My guess, based on a reasonable background in electronics, is the power supply to the pre-amp circuit. I would expect this to be a soft-start type to prevent such clicks, but if a capacitor (or other linked component) has failed, it will be an instant 'on' which would produce a click. Check for any burnt out low value resistors, swollen electrolytic capacitors, or obvious signs of overheating on the PCB. Link to comment Share on other sites More sharing options...
Rob_Beech Posted August 23, 2009 Share Posted August 23, 2009 Slightly OT, Kevin, do you like servicing them? If so, would you like 2? Link to comment Share on other sites More sharing options...
bruce Posted August 23, 2009 Share Posted August 23, 2009 ... or even 3 :) I've got one that has been lying in a box for a year, waiting for me to work up the motivation to think about repairing it. Symptoms: occasionally works, but most times gives error when trying to read a disk. Link to comment Share on other sites More sharing options...
Rob_Beech Posted August 23, 2009 Share Posted August 23, 2009 Symptoms of mine : Unit number 1 : Won't read, anything. At all. Ever. Unit number 2 : Wont' read some, but will read most, though you often have to insert the CD, then switch the unit OFF and ON before it reads. Then occasionally it has a bit of a do and packs up. Got an 1800F with occasional issues on the right hand deck too. Link to comment Share on other sites More sharing options...
bruce Posted August 23, 2009 Share Posted August 23, 2009 Mine sounds a bit like unit #2... Link to comment Share on other sites More sharing options...
David Duffy Posted August 24, 2009 Share Posted August 24, 2009 Overall, DN650's are a pretty reliable unit. Just the usual laser, spindle motor wearing out most of the time. Link to comment Share on other sites More sharing options...
Grahame Posted August 24, 2009 Author Share Posted August 24, 2009 An update on this - I discovered that the Tascam minidisc in the same rack had the same problem on the play button, which made me very suspicious. I tried swapping from the balanced outputs on the Denon to the unbalanced outputs, and everything seems fine. I suspect it's more to do with the crappy DJ mixer that I'm running it through than any fault in the CD player. Anyway, problem worked around if not solved, and only three more shows to go. :)! Link to comment Share on other sites More sharing options...
Glyn Edwards Posted August 24, 2009 Share Posted August 24, 2009 ...Tascam minidisc ... I've had similar problems using Tascam CD players on a Yamaha O1V96, we eventually traced the problem to the fact that the desk was supplying phantom power to the CD channels. Might be worth checking your mixer isn't doing the same. HTH Glyn Link to comment Share on other sites More sharing options...
Grahame Posted August 25, 2009 Author Share Posted August 25, 2009 we eventually traced the problem to the fact that the desk was supplying phantom power to the CD channels.I had a similar thought Glyn, and that was one of the first things I checked. As far as I can tell, the phantom on the channels is disabled - at least, the buttons aren't depressed - but maybe there's some other master setting on the desk that I haven't discovered. Link to comment Share on other sites More sharing options...
mervaka Posted August 25, 2009 Share Posted August 25, 2009 stick a meter into the socket. Link to comment Share on other sites More sharing options...
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