AVITWeb Posted December 8, 2011 Report Share Posted December 8, 2011 Hey guys. Wondering if anyone has hit this before. I own an MZ-NH900...great machine.. But I have been having problems lately with it not being able to read standard recording MDs. It works flawlessly with HiMDs or standard discs recorded in Hi. Most often it will not be able to read the disc or it will play 2 to 3 seconds of a song at a time. Like its having a problem reading the surface. My standard MD player will play them with no problem at all. Any ideas? Thanks in advance. Quote Link to comment Share on other sites More sharing options...
sfbp Posted December 8, 2011 Report Share Posted December 8, 2011 Laser Power adjust. No doubt at all. The settings for MD and HiMD veer off in opposite directions, and the alignment procedure puts the LP exactly in the middle of the two. Too high and you can't read MD, too low and you can't read HiMD (mind you this only really affects 1GB HiMD). Quote Link to comment Share on other sites More sharing options...
AVITWeb Posted December 8, 2011 Author Report Share Posted December 8, 2011 Thanks for the reply. Actually it happens on standard MDs when "burned" in MD mode not HiMD. But the funny part is that the disc I was listening to today, it happened for the first few tracks and then i was able to listen to the rest of the disc. How would one get the power "adjusted?" Is this a send in for service thing? Quote Link to comment Share on other sites More sharing options...
sfbp Posted December 8, 2011 Report Share Posted December 8, 2011 I meant that "too low and you can't read HiMD" affects 1GB disks only. The service manual outlines how to adjust it. You will probably need a Laser Power Meter, that costs more than the value of your unit, is the only problem. Sony no longer services MD's. Some they will replace, but most are not considered serviceable or replaceable. I have had reasonable success with adjusting them myself but I don't offer a paid service (yet). Jim Hoggarth in UK is getting close to having a paid service (he generally fixes MD's for a fee, but just doesn't have a lot of call for adjusting HiMD, up to the present time). Quote Link to comment Share on other sites More sharing options...
PhilippeC Posted December 9, 2011 Report Share Posted December 9, 2011 Where are you living AVITWeb ? Quote Link to comment Share on other sites More sharing options...
AVITWeb Posted December 9, 2011 Author Report Share Posted December 9, 2011 I'm in the US. Thanks for the info guys! Quote Link to comment Share on other sites More sharing options...
PhilippeC Posted December 10, 2011 Report Share Posted December 10, 2011 Too far for a postage. My NH900 with only button problems was perfect for sharing spare parts. Quote Link to comment Share on other sites More sharing options...
sfbp Posted December 10, 2011 Report Share Posted December 10, 2011 Is the Gordon in ur profile the "big engine"? heheh Quick question: is the screen perfectly readable? Or is it rather faint, bordering on invisible? Quote Link to comment Share on other sites More sharing options...
PhilippeC Posted December 10, 2011 Report Share Posted December 10, 2011 It is a question for me Stephen ? My NH900 got two screen, the second one came two years ago from Sony Singapour for 30$ (I still have the first one). But for me it has been always too faint. Quote Link to comment Share on other sites More sharing options...
sfbp Posted December 10, 2011 Report Share Posted December 10, 2011 Was a question for OP. If screen is too faint you definitely need power adjust (not LP, just the main power on the unit). Easy to do. Quote Link to comment Share on other sites More sharing options...
AVITWeb Posted May 5, 2014 Author Report Share Posted May 5, 2014 Oh my...It has been so long...I am so sorry for not responding! Actually, the display and everything else about the unit is fine. And this does not happen all the time nor with all discs. Just some. And some, the player gives me a read error. Quote Link to comment Share on other sites More sharing options...
sfbp Posted May 5, 2014 Report Share Posted May 5, 2014 As I said (2.5 years ago), Laser power adjust. Quote Link to comment Share on other sites More sharing options...
AVITWeb Posted May 5, 2014 Author Report Share Posted May 5, 2014 Sorry...wasn't asking again...just adding to my point is all. thanks! Quote Link to comment Share on other sites More sharing options...
sfbp Posted May 6, 2014 Report Share Posted May 6, 2014 On the contrary, you answered me that it's likely not the overall power to the unit but only the laser power (or possibly the laser itself). Now Jim is back you may be able to get it fixed. The fact that it reads HiMD but not MD suggests one of two things: 1. the MD disks were recorded by a unit that is a bit "off", or; 2. the sub-alignment for the different laser powers needs to be tweaked. One can do this with a laser power meter, but really the best is to do the automatic servo alignment as per the service manual. Quote Link to comment Share on other sites More sharing options...
AVITWeb Posted May 6, 2014 Author Report Share Posted May 6, 2014 Thank you! Quote Link to comment Share on other sites More sharing options...
PhilippeC Posted May 6, 2014 Report Share Posted May 6, 2014 Hey Stephen, Jim is really back ? Quote Link to comment Share on other sites More sharing options...
AVITWeb Posted May 8, 2014 Author Report Share Posted May 8, 2014 So the only real way to do it is with a prerecorded MD? Quote Link to comment Share on other sites More sharing options...
AVITWeb Posted May 8, 2014 Author Report Share Posted May 8, 2014 I downloaded the service manual, and in there it mentions that you need a piece of software on a computer in order to get the unit to enter service mode. I know I have seen others here enter service mode with button presses. I am looking around here for that now. Quote Link to comment Share on other sites More sharing options...
AVITWeb Posted May 8, 2014 Author Report Share Posted May 8, 2014 Checked the service manual for the NH900 and 2 key points. One is the fact that it says you need software on a computer to enter service mode. I know I have seen others here use a key combination on a remote to get into the mode but have had no luck finding it for my specific unit (maybe they are the same?) Secondly it says it requires two discs. One I have read is a pre-recorded MD and the other I did not recognize. Any of you folks know how to proceed? Or at least the direction I should be heading? Thanks. Quote Link to comment Share on other sites More sharing options...
sfbp Posted May 8, 2014 Report Share Posted May 8, 2014 Warning: do not proceed unless you have (lots of experience in electronic repair) and all the gear: 1. Three types of test disks (2 you can manufacture yourself, but you will need working HiMD unit/s to do it. If your only HiMD is the one you are trying to service, in the immortal words of Hugh Grant "fuhgeddaboudid") 2. Regulated power supply (preferably x2) and precision voltmeter 3. Laser Power meter 4. Soldering iron in the event you brick things and have to hardwire the thing into service mode. Holding down group button, with hold turned on permanently, press FF FF RW RW FF RW FF RW || || (the last two are pressing "Pause"). Quote Link to comment Share on other sites More sharing options...
sfbp Posted May 8, 2014 Report Share Posted May 8, 2014 Please don't scatter this one enquiry of yours over 5 or 6 different topics. Everyone reads everything. No need, and it's just annoying. Quote Link to comment Share on other sites More sharing options...
AVITWeb Posted May 9, 2014 Author Report Share Posted May 9, 2014 Will do...Thanks for the information, I appreciate it! When you say "make" are you simply referring to creating my own disc of anything? Quote Link to comment Share on other sites More sharing options...
sfbp Posted May 9, 2014 Report Share Posted May 9, 2014 Yup. You can make the HiMD1 and HiMD3 yourself. But u will need to purchase a CD. Quote Link to comment Share on other sites More sharing options...
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