tigerwoodKhorns Posted December 30, 2022 Share Posted December 30, 2022 I have a Musical Fidelity CD Pre 24 that has a CD player built in that has stopped working. This unit has a preamp, DAC and CD player all in one chassis and was made in 2002. The mechanism is a Sony CD transport that uses a KSS 213B laser. The transport has 'Sony BO-25' in a few places. I have the transport out and hooked up. The drawer will open and close but the CD does not spin up. I also cannot see any light coming from the laser (I did not look into it, just from the side in a dark room). I tried to adjust the laser using the potentiometer but nothing. If the laser is bad, will the disc also not spin (or even try to spin) or do I possible have a bad motor and a bad laser? Any advice or even where to get a whole new transport from a donor as this looks like a very common transport. Quote Link to comment Share on other sites More sharing options...
the real Duke Spinner Posted December 30, 2022 Share Posted December 30, 2022 I believe there are separate voltages for each PS problem Quote Link to comment Share on other sites More sharing options...
tigerwoodKhorns Posted December 31, 2022 Author Share Posted December 31, 2022 20 hours ago, the real Duke Spinner said: I believe there are separate voltages for each PS problem I did unplug the power jumper to the CD mechanism to see if it acted different and it did. I figured if it acted the same then no power from the PS board. I guess this can be a problem in the CD drive - does it transform voltages internally? These are so common I would not mind just replacing the whole thing if I can find a good donor. Quote Link to comment Share on other sites More sharing options...
Marvel Posted December 31, 2022 Share Posted December 31, 2022 I had a short (very short) bit on CD mechanisms in an electronics class about 30 yrs ago. I do know that the laser/lens tries about three times to focus on the CD. If it can't, it errors out or shuts off. It requires the lens to be clean (obviously) for it to work. Other than that tidbit, I got rid of my class info some time ago during a housecleaning purge so I'm no help. Quote Link to comment Share on other sites More sharing options...
Marvel Posted December 31, 2022 Share Posted December 31, 2022 And... I think the mechanism for the laser assembly slides on a couple rods/rails. Make sure they are clean and lubed. If the assembly can't move, it won't work. Quote Link to comment Share on other sites More sharing options...
Invidiosulus Posted December 31, 2022 Share Posted December 31, 2022 On 12/29/2022 at 11:30 PM, tigerwoodKhorns said: I have the transport out and hooked up. The drawer will open and close but the CD does not spin up. I also cannot see any light coming from the laser (I did not look into it, just from the side in a dark room). Iirc CD lasers are in the infrared range and you probably won’t see it with the naked eye. if you have a night vision camera it should pick something up. I feel like on the game systems I’ve worked on that the disc would spin up Initially even with the laser out of commission. Quote Link to comment Share on other sites More sharing options...
tigerwoodKhorns Posted January 2 Author Share Posted January 2 OK, I worked on this again. I posted the following over at DIY Audio, and any input here is also appreciated. It seems that if the laser senses the CD prior to spinning the motor I just need a new laser, but I am not familiar with how this transport works. *** *** First post here. I have a Musical Fidelity CD PRE 24 made in 2002 that has a Sony based CD transport with a KSS 213B laser. I took it apart and when I try to load a disc, the drawer closes and the laser board swings up, then the eye of the laser bobs up and down two times and the disc does not spin. Does the laser 'fire' first and then the CD spins or should the motor for the CD also be spinning? If the laser fires first I think that I should just try to replace it. Here is what I have done so far: Removed the drawer motor, check the contact switches, cleaned them with Deoxit, added a drop of oil on the motor shaft (motor spins freely), and a little grease on the shafts holding the gears. Cleaned the laser eye with alcohol. When the laser bobs up and down there is no visible light. I was careful not to look right at it. Tried to adjust the laser intensity - this did nothing. Hopefully I did no damage by doing this. The CD drive motor spins freely and there is no black dust or anything in the chassis to suggest the bearings are shot. The gears on the laser mechanism look good, no cracks in the small drive gear. I tried to use the unit with the ribbon and power to the CD transport unhooked, the unit acted differently and did not do anything. I figured that if it acted the same the issue could be something in another board. I use the unit every day but the CD player has not been used in years. Worked fine last time I used it I think. I might be wrong but I don't remember any skipping but I think it might have had trouble recognizing some discs. It has been a while. Any help is appreciated. If the Laser senses the CD prior to starting the motor I think that this is just a bad laser. Thank you for any help. Quote Link to comment Share on other sites More sharing options...
OO1 Posted January 2 Share Posted January 2 18 minutes ago, tigerwoodKhorns said: Sony based CD transport with a KSS 213B laser. I think that this is just a bad laser. yeah ..... I would replace the laser if memory serves me well , when the CD unit does not spin , this is usually indicative that the laser or the electronics are bad ...... in any case , the old laser unit is definitely very tired after 20 years Quote Link to comment Share on other sites More sharing options...
tigerwoodKhorns Posted January 2 Author Share Posted January 2 23 minutes ago, OO1 said: yeah ..... I would replace the laser if memory serves me well , when the CD unit does not spin , this is usually indicative that the laser or the electronics are bad ...... in any case , the old laser unit is definitely very tired after 20 years So the pattern is fire the laser, then if it senses a CD spin up the CD? I don't mind replacing the laser, but it will not be a genuine part even if they say it is so who knows what I am replacing it with. Quote Link to comment Share on other sites More sharing options...
Jhakobe Posted January 2 Share Posted January 2 Ok, this is a looong shot, and not technical - I’ve worked on two cd/dvd players that had a sensor for disc loading that was faulty. My dumba** workaround was to create a chapeau, or a hat, of electrical tape surrounding the sensor. I presumed the sensors were photovoltaic and the tape was enough to convince the disc it was dark enough to load. Probably the dumbest thing you’ve read in a while but they achieved many years of operation after this “fix”. Quote Link to comment Share on other sites More sharing options...
tigerwoodKhorns Posted January 2 Author Share Posted January 2 17 hours ago, Jhakobe said: Ok, this is a looong shot, and not technical - I’ve worked on two cd/dvd players that had a sensor for disc loading that was faulty. My dumba** workaround was to create a chapeau, or a hat, of electrical tape surrounding the sensor. I presumed the sensors were photovoltaic and the tape was enough to convince the disc it was dark enough to load. Probably the dumbest thing you’ve read in a while but they achieved many years of operation after this “fix”. Good idea. I already removed the drawer motor board and cleaned the contacts on the open and close sensors. They work and test well. I think that the laser is the most obvious right now, but I prefer not to just start replacing parts. Quote Link to comment Share on other sites More sharing options...
JL Sargent Posted January 2 Share Posted January 2 2 hours ago, tigerwoodKhorns said: but I prefer not to just start replacing parts. That laser can be had for crazy cheap on Ebay if you don't mind waiting a bit. https://www.ebay.com/itm/181847044701?hash=item2a56edb25d:g:X7AAAOSwwNVTs4U5&amdata=enc%3AAQAHAAAAoFLvFVdauHGaeJm7x4seukmpksoR6M1OAx4OLfXb%2B7WIIj3hlkPprBPZ18VcEW3KUrpoIyZRfHWF%2FzIhO364tHBg9H08Tjr6KNdz3HUIp0OwvGaRfFwJqZ2e3K5wPmjBDbMv3KZTYDoRsyZBp1%2FPcomW3CL7BRryi2FekUHqzI8BKatYlS99OuYVUG0E0Uhj1IOUA%2FTNcH97aMpaQni%2FAXc%3D|tkp%3ABk9SR8zK_8iuYQ Quote Link to comment Share on other sites More sharing options...
OO1 Posted January 2 Share Posted January 2 22 hours ago, tigerwoodKhorns said: So the pattern is fire the laser, then if it senses a CD spin up the CD? I don't mind replacing the laser, but it will not be a genuine part even if they say it is so who knows what I am replacing it with. New Head assembly ....EBAY 13-14$ PART # KSM-213CCM https://www.ebay.com/itm/274856618622?_trkparms=amclksrc%3DITM%26aid%3D1110006%26algo%3DHOMESPLICE.SIM%26ao%3D1%26asc%3D244401%26meid%3D0f6059edf6fc47a78a22ad24296b7235%26pid%3D101195%26rk%3D1%26rkt%3D12%26sd%3D113797657536%26itm%3D274856618622%26pmt%3D1%26noa%3D0%26pg%3D2047675%26algv%3DSimplAMLv11WebTrimmedV3MskuWithRevOptLambda85KnnRecallV1TitleRecall&_trksid=p2047675.c101195.m1851&amdata=cksum%3A2748566186220f6059edf6fc47a78a22ad24296b7235|enc%3AAQAHAAABIFWRPpf%2FDa5vn4SEuceq169ve1nVKV2UcyqVYubu5TTZcmr03O0GOPfaRlPO9XKtRjV%2FbOgI%2B%2FqMfHfAKhc8QsAI323ppBo73KiWBZ2FeDt8kgXmHxIvwslH7vXFQbiU5D2vYO41FPonN9jExP5nK7R6GIZpWKEDluGBqYoBU6wIS4UkTYNiT4YYpp7fHlLWhbItuC%2FQ8EJ7ScINhn7Jt5h7QCwHtYdyvHWJjle1vxPHiNjZsZ66KL5zc0kV8dkPl8hiK5daV8I0yyr%2FdFj0ImsA4KsS0V4cApn1vW950fL1NEqC3Z9VDJ5Rm49s2OTKdgfYVKG6m50E%2Bn25y997F9vTOduaM2IUjao381rXvNd5a7Xi0CE2PIUrVXh3bhS%2BdA%3D%3D|ampid%3APL_CLK|clp%3A2047675 Quote Link to comment Share on other sites More sharing options...
tigerwoodKhorns Posted January 3 Author Share Posted January 3 OK, this video at 6 minutes shows that the laser fires before the CD drive motor to sense if a CD is present. It looks like the laser emits some light which mine does not so I need a laser. Looks like to install this I need an oscilloscope. Does the whole head assembly avoid this? Quote Link to comment Share on other sites More sharing options...
tigerwoodKhorns Posted January 3 Author Share Posted January 3 5 hours ago, JL Sargent said: That laser can be had for crazy cheap on Ebay if you don't mind waiting a bit. https://www.ebay.com/itm/181847044701?hash=item2a56edb25d:g:X7AAAOSwwNVTs4U5&amdata=enc%3AAQAHAAAAoFLvFVdauHGaeJm7x4seukmpksoR6M1OAx4OLfXb%2B7WIIj3hlkPprBPZ18VcEW3KUrpoIyZRfHWF%2FzIhO364tHBg9H08Tjr6KNdz3HUIp0OwvGaRfFwJqZ2e3K5wPmjBDbMv3KZTYDoRsyZBp1%2FPcomW3CL7BRryi2FekUHqzI8BKatYlS99OuYVUG0E0Uhj1IOUA%2FTNcH97aMpaQni%2FAXc%3D|tkp%3ABk9SR8zK_8iuYQ I found a Seller with 100% feedback, has a lot on stock, 60 day returns and Seller pay return shipping. All for $20 or so, seems money well spent. 1 Quote Link to comment Share on other sites More sharing options...
tigerwoodKhorns Posted January 29 Author Share Posted January 29 A quick reply in case anyone is in my situation with a Sony based CD player. I just finished the laser swap and it is playing beautify. Listening to Pink Floyd played by a symphony. If you have a CD player with a Sony KSS laser, if the laser is bad, the disc will not spin up, it doesn't mean something else is bad (at least the KSS 213). A KSS 213C replaced a KSS 213B laser, no problem. The laser just gets installed, no adjusting the pot, as a matter of fact, mark the preset position of the pot in case it ever gets moved. Make sure you de-solder the short out that protects the laser from static. I also used a little (very little) lithium grease on the parts that were greased before. 4 Quote Link to comment Share on other sites More sharing options...
wuzzzer Posted January 29 Share Posted January 29 Awesome! Worth the effort to get it up and running again. 1 Quote Link to comment Share on other sites More sharing options...
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