fade2black101 Posted October 10, 2012 Report Share Posted October 10, 2012 Hello I received one of these units from ebay today. I have two now and both are in immaculate condition. However, the one I received today makes an incredibly loud screeching noise very frequently when seeking tracks. Almost like the motor is spinning the disc super fast! Since the other one doesn't do this, I'm wondering what it means and if it is damaging the unit? Thanks in advanced for any help Quote Link to comment Share on other sites More sharing options...
sescoscuba Posted October 10, 2012 Report Share Posted October 10, 2012 Hi, i think Jim Hoggarth is you man. He replay to you very soon. Ciao Sergio Quote Link to comment Share on other sites More sharing options...
fade2black101 Posted October 10, 2012 Author Report Share Posted October 10, 2012 Hopefully he'll know what's going on.. It seems to do it when I skip a few tracks up and make a big jump between tracks. The screeching sound is also VERY loud. Enough to put me off using it in public. Quote Link to comment Share on other sites More sharing options...
fade2black101 Posted October 10, 2012 Author Report Share Posted October 10, 2012 If someone can kindly tell me how to upload a file, I'll show you what it sounds like. Nevermind.. .Here we go http://www.filedropp...om/loudminidisc This is just from me inserting a new minidisc and then doing nothing. The first track of the MD though was "moved" from the end of the disc though, so the noise must be in relation to the optical pickup moving frantically to a higher track. Quote Link to comment Share on other sites More sharing options...
jim.hoggarth Posted October 12, 2012 Report Share Posted October 12, 2012 Hi folks - thanks for the off-site heads up Christos, I missed this originally. This is caused by another of Sony's brilliant design cock-ups. The N910 was a transitional unit, from the old N710-style chassis and pickup/motors to the newer Hi-MD style chassis/motors/pickup. But, the intermediate sled transmission gear on the N910 is far too large in my opinion. Indeed, later models had a similar motor chain design but the sled motor capstan was made larger and the transmission gear smaller. I assume, because of this problem. During fast track seeks the big gear must hit some resonant frequency with the result it vibrates like hell. This only happens in one direction, because the force of driving the sled shaft helical gear causes the sled transmission gear to lift in one direction and fall in the other. Frictional components are presumably different in these two positions, hence it only resonates on the 'outward' journey to the higher tracks (this is from memory, so it may be the other way around!). The correct solution is to replace the sled gear with one with a different resonant frequency. I would assume some drastic action such as removing a small amount of plastic from the gear would have a similar effect, although I have not attempted this (I may just try now, perhaps two small holes drilled at diametric opposite positions). The other solution, which is quick and easy but not really ideal, is to add extra drag to the gearing chain. A minute smear of silicon grease does just this. I grease the part where the transmission gear drives the helical shaft gear. BUT - be aware that too much grease and you can hear the loading effect as the gearing mechanism starts slowly and gradually speeds up. A case of less is more. Jim Quote Link to comment Share on other sites More sharing options...
fade2black101 Posted October 12, 2012 Author Report Share Posted October 12, 2012 Hi folks - thanks for the off-site heads up Christos, I missed this originally. This is caused by another of Sony's brilliant design cock-ups. The N910 was a transitional unit, from the old N710-style chassis and pickup/motors to the newer Hi-MD style chassis/motors/pickup. But, the intermediate sled transmission gear on the N910 is far too large in my opinion. Indeed, later models had a similar motor chain design but the sled motor capstan was made larger and the transmission gear smaller. I assume, because of this problem. During fast track seeks the big gear must hit some resonant frequency with the result it vibrates like hell. This only happens in one direction, because the force of driving the sled shaft helical gear causes the sled transmission gear to lift in one direction and fall in the other. Frictional components are presumably different in these two positions, hence it only resonates on the 'outward' journey to the higher tracks (this is from memory, so it may be the other way around!). The correct solution is to replace the sled gear with one with a different resonant frequency. I would assume some drastic action such as removing a small amount of plastic from the gear would have a similar effect, although I have not attempted this (I may just try now, perhaps two small holes drilled at diametric opposite positions). The other solution, which is quick and easy but not really ideal, is to add extra drag to the gearing chain. A minute smear of silicon grease does just this. I grease the part where the transmission gear drives the helical shaft gear. BUT - be aware that too much grease and you can hear the loading effect as the gearing mechanism starts slowly and gradually speeds up. A case of less is more. Jim Thanks for the reply and detailed explanation JIm. Not sure I have the confidence in opening the unit up and attempting the grease fix, and this seems like a temporary solution too. Hopefully this fix this help others though who have a similar problem and the confidence and knowledge to perform the fix themselves. I don't know if this loud screeching is detrimental to the lifespan of the unit, but it is incredibly loud and annoying so I will contact you about a possible repair if possible. Quote Link to comment Share on other sites More sharing options...
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