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Old 3rd February 2013, 07:05 PM   #11
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I keep seeing post's that mention the CXD2500 dying but no further info on why or how or symptoms of a dead 2500??
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Old 3rd February 2013, 07:13 PM   #12
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Originally Posted by stephensank View Post
There are basically three major weak links in that vrds, the loading gears, the spindle motor and the laser. Seems the gears are fine so far(bit of a miracle). If the laser is doing as you say, then the spindle motor is not being told to start, as focus is failing, so won't know about that until focus is achieved. With extremely rare exceptions, KSS240's don't drift out of range, but are simply either good or bad, or lens is very dirty. Assuming a clean lens, your are very, very likely needing a new laser. I would say you are wasting your time looking for other faults until you try one. I'd say it is easily 95% likely that the new laser will cure it. One preventive step on the motor you should take, though, is to give it a "silicone treatment", meaning find an electrically safe silicone-based spray lubricant, then spray a small shot of it into each of the two slots in the motor that will be shown when the dress plate is removed from the top. This will dislodge & prevent carbon buildup on the commutator, and generally cure any non-working motor of this type.
Thanks, I did disconnect the spindle motor from the servo board and applied 3v dc to the motor and it did spin! I also reversed the polarity and made sure it would spin backwards as well. so I feel the motor is good. I traced through the whole motor control circuit all the way to the CXD2500 IC and i see no life on that line so I do believe the motor is not being told to start.

Assuming that this laser is toast and will need to be replaced. I wonder if i could turn the laser power up and see if it will at least show any signs of life? If i could at least get it to focus enough to spin the disc and try and read the TOC then i would just yank and replace the laser. I just don't want to waste ANY $$ (i have zero) buying a laser only to find out that the servo board it toast. if i could at least see some signs of life then i would feel much better investing in it.
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Old 3rd February 2013, 07:13 PM   #13
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It is pretty darn rare for CXD2500 to fail without lightning damage. I have only had to replace ONE in the last 20+ years of prof. service work. Your symptoms do not indicate any reason to suspect it's bad. It is the signal proc, not servo control, so a bad one will not manifest, if it's not running hot, until you have a cd playing, and either no sound or distorted sound/noise coming out. You also won't see any rf output from a laser that could not get focus.
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Old 3rd February 2013, 07:15 PM   #14
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These lasers are pretty inexpensive, even from reputable sources. In the USA, most reliable sources are MCM and Parts Express, which should both have stock of these. Dalbani is also good, but does carry 'generics', but always indicates when parts are thus. The 240 usually has perfectly good laser power when defective, as it seems to always be the receiving end of it that goes bad.
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Old 3rd February 2013, 07:16 PM   #15
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Originally Posted by stephensank View Post
It is pretty darn rare for CXD2500 to fail without lightning damage. I have only had to replace ONE in the last 20+ years of prof. service work. Your symptoms do not indicate any reason to suspect it's bad. It is the signal proc, not servo control, so a bad one will not manifest, if it's not running hot, until you have a cd playing, and either no sound or distorted sound/noise coming out. You also won't see any rf output from a laser that could not get focus.

ahhh Ok, I will order a new laser then! I might have one at work, will check on Monday!
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Old 3rd February 2013, 07:17 PM   #16
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Quote:
Originally Posted by stephensank View Post
These lasers are pretty inexpensive, even from reputable sources. In the USA, most reliable sources are MCM and Parts Express, which should both have stock of these. Dalbani is also good, but does carry 'generics', but always indicates when parts are thus. The 240 usually has perfectly good laser power when defective, as it seems to always be the receiving end of it that goes bad.

That might explain why these just stop working suddenly?
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Old 4th February 2013, 01:59 AM   #17
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That might explain why these just stop working suddenly?
Yes, it would. You should also check that there are no cracks in the conductors of the ribbon cable that goes to it, particularly anywhere the ribbon is or has been folded.
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Old 4th February 2013, 11:35 PM   #18
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Only had a few minutes tonight, turning the laser power control made no difference just as you suggested. I will order a new laser and see what happens.
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Old 6th February 2013, 02:00 AM   #19
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OH YEAH! this laser is TOAST! I disassembled the transport tonight and pulled the laser block out and right away I could see that the circuit board under the three trimmer pots was discolored. removing the circuit board shows the transistor that controls the laser and a resistor next to it is burned to a crisp! not charred but very very discolored and obviously overheated. so yeah, new laser time.


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Old 6th February 2013, 02:33 AM   #20
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Wow, I can't recall a single time seeing a Sony laser visibly damaged like that, other than first gen KSS100's with melted top ends from the focus/tracking drive hybrid IC's shorting. Would not have expected that, but sure explains the sudden death.
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