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Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems. |
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#1
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Sony pickup whacks furiously
Can any one help me with my CD player? It's a Sony component CD player that uses KSS-240 pickup. My problem is, as soon as the player is powered on, the lens head will be immediately starting whacking up and down, something like machine gun fires. The objective lens overshoots and hits, making a sound somewhere like 10hz beating/whacking sounds. It won't stop until powered off. Does anyone know how I can fix this?
Thanks a lot, SY |
#2
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Sony pickup whacks furiously
Hello,
You did not mention what CD player the pickup is in, but a rapid fire of the lens like that is not likely to be the pickup. It is more likely to be a driver IC problem or a clock failure. Regards, Tim Schwartz Bristol Electronics SY Chun wrote: Can any one help me with my CD player? It's a Sony component CD player that uses KSS-240 pickup. My problem is, as soon as the player is powered on, the lens head will be immediately starting whacking up and down, something like machine gun fires. The objective lens overshoots and hits, making a sound somewhere like 10hz beating/whacking sounds. It won't stop until powered off. Does anyone know how I can fix this? Thanks a lot, SY |
#3
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Sony pickup whacks furiously
"SY Chun" wrote in message ... Can any one help me with my CD player? It's a Sony component CD player that uses KSS-240 pickup. My problem is, as soon as the player is powered on, the lens head will be immediately starting whacking up and down, something like machine gun fires. The objective lens overshoots and hits, making a sound somewhere like 10hz beating/whacking sounds. It won't stop until powered off. Does anyone know how I can fix this? Thanks a lot, SY If the player has what's called ( by Sony ) a ' B ' board mounted immediately under the deck, with the spindle and sled motors soldered straight into it, look for 3 or 4 surface mount electrolytics along one edge - there's various versions of this board. I think that they are 47uF as I recall. They commonly go open circuit, but also, one of them is prone to actually leak, and the electrolyte usually attacks a nearby through plated hole, which must then be ' wired around '. It is ESSENTIAL that the caps are replaced with similar surface mount types. Ordinary wire ended types WILL NOT work. All of these caps are on pins of the servo processor IC, and the symptoms you describe are typical of their failure. Arfa |
#4
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Sony pickup whacks furiously (another thought)
Sy,
Besides driver IC's and clocks, you could have a very noisy power supply. You'll need to look at the supplies with a scope. Regards again, Tim SY Chun wrote: Can any one help me with my CD player? It's a Sony component CD player that uses KSS-240 pickup. My problem is, as soon as the player is powered on, the lens head will be immediately starting whacking up and down, something like machine gun fires. The objective lens overshoots and hits, making a sound somewhere like 10hz beating/whacking sounds. It won't stop until powered off. Does anyone know how I can fix this? Thanks a lot, SY |
#5
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Sony pickup whacks furiously
Dear Arfa,
I was able to locate those 3 electrolytics and confirm that leakage from the middle one!!! It caused the neighboring parts and plated holes spoiled and eroded. Now my quest is how and where to get the surface mount electrolytics... Thanks for your wonderful help and amazing knowledge! SY "Arfa Daily" wrote in message ... "SY Chun" wrote in message ... Can any one help me with my CD player? It's a Sony component CD player that uses KSS-240 pickup. My problem is, as soon as the player is powered on, the lens head will be immediately starting whacking up and down, something like machine gun fires. The objective lens overshoots and hits, making a sound somewhere like 10hz beating/whacking sounds. It won't stop until powered off. Does anyone know how I can fix this? Thanks a lot, SY If the player has what's called ( by Sony ) a ' B ' board mounted immediately under the deck, with the spindle and sled motors soldered straight into it, look for 3 or 4 surface mount electrolytics along one edge - there's various versions of this board. I think that they are 47uF as I recall. They commonly go open circuit, but also, one of them is prone to actually leak, and the electrolyte usually attacks a nearby through plated hole, which must then be ' wired around '. It is ESSENTIAL that the caps are replaced with similar surface mount types. Ordinary wire ended types WILL NOT work. All of these caps are on pins of the servo processor IC, and the symptoms you describe are typical of their failure. Arfa |
#6
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Sony pickup whacks furiously
"SY Chun" wrote in message ... Dear Arfa, I was able to locate those 3 electrolytics and confirm that leakage from the middle one!!! It caused the neighboring parts and plated holes spoiled and eroded. Now my quest is how and where to get the surface mount electrolytics... Thanks for your wonderful help and amazing knowledge! SY Hi there You should be able to get exact replacements, or similar types, from virtually any regular component supplier. You can get away with slightly higher voltage working ones, which are more readily available. If memory serves, the originals are rated at 4v working, and replacements at 6.3v working are more readily available. However, they are slightly larger, so you've got to be a bit a bit more careful fitting them. I don't know whereabouts in the world you are, but here in the UK, they are available from www.chsinteractive.co.uk under part number 5397736 but they are special order, which is usually 7 -10 days delay, and I don't know if they have international shipping arrangements. The manufacturer seems to be Jaeger, so maybe you could do a search on that. When you come to fit replacements, it is essential that all of the leaked electrolyte is removed from the board, and the affected area chemically neutralised. You can do this using electronics grade ( 99.7% ) isopropyl alcohol, and an old toothbrush. Also, it is essential, if it is to ever work again, that the damaged through plated holes are properly dealt with. Use a strong magnifier, or jeweller's eyepiece to examine the areas where the tracks join the edges of the affected holes. You will often find that if you give this area a little scrape with a blunt curve-blade scalpel edge to remove the blackening, that the actual track is eaten away. As I recall, it's difficult to see where at least one of the tracks finally goes to, as once it has gone to the underside of the board, it goes for a short distance, then comes up again through another through plated hole to the top of the board, but under the servo processor IC, where you then can't see what pin it finishes up at. At a pinch, you can carefully drill out any affected holes where you can get at both sides, using a model-makers drill, and feed a thin wire through the hole, soldering to the nearest piece of undamaged track on the run to the hole, on both sides. If you can tell me the model number of the CD player, I might have the manual, or a similar one that we can use to determine exactly to where each cap is ultimately connected. I have done many of these over the years, though not so many recently, as they are getting old now. They are definitely always repairable in the end, but require much patience to repair the damage caused, and may cause you more than a little frustration along the way ... Arfa |
#7
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Sony pickup whacks furiously
Dear Arfa,
You make me clearly envision what to do over the coming weekend. No problem with the old toothbrush... I live in Seoul, Korea. I may go out to electoronic parts shops to buy the part. Normally the vendors out there don't treat a customer like me well who choose to purchase an item by 1-2 in quantity. So, one of my realistic alternatives would be wandering around Sony service center junkyard, very luckily I have one nearby, to look for a scrap. The CD player came out from Sony mini component system, FH-E838CD. The player has its own model number of CDP-H3600. Personally this is an important project. In order to re-establish the order within the family, recently I declared to my family members, my wife more particularly, that it will be fixed by me (to prove that I do have and maintain a sound and still working brain system). As I became weak-sighted, looking tiny things becomes an obstacle. Yes, I think I need jeweller's eyepiece. I hope a sunny and clear weekend for the operation. I also like your encouragement: Its always repairable. Thanks a lot. SY "Arfa Daily" wrote in message ... "SY Chun" wrote in message ... Dear Arfa, I was able to locate those 3 electrolytics and confirm that leakage from the middle one!!! It caused the neighboring parts and plated holes spoiled and eroded. Now my quest is how and where to get the surface mount electrolytics... Thanks for your wonderful help and amazing knowledge! SY Hi there You should be able to get exact replacements, or similar types, from virtually any regular component supplier. You can get away with slightly higher voltage working ones, which are more readily available. If memory serves, the originals are rated at 4v working, and replacements at 6.3v working are more readily available. However, they are slightly larger, so you've got to be a bit a bit more careful fitting them. I don't know whereabouts in the world you are, but here in the UK, they are available from www.chsinteractive.co.uk under part number 5397736 but they are special order, which is usually 7 -10 days delay, and I don't know if they have international shipping arrangements. The manufacturer seems to be Jaeger, so maybe you could do a search on that. When you come to fit replacements, it is essential that all of the leaked electrolyte is removed from the board, and the affected area chemically neutralised. You can do this using electronics grade ( 99.7% ) isopropyl alcohol, and an old toothbrush. Also, it is essential, if it is to ever work again, that the damaged through plated holes are properly dealt with. Use a strong magnifier, or jeweller's eyepiece to examine the areas where the tracks join the edges of the affected holes. You will often find that if you give this area a little scrape with a blunt curve-blade scalpel edge to remove the blackening, that the actual track is eaten away. As I recall, it's difficult to see where at least one of the tracks finally goes to, as once it has gone to the underside of the board, it goes for a short distance, then comes up again through another through plated hole to the top of the board, but under the servo processor IC, where you then can't see what pin it finishes up at. At a pinch, you can carefully drill out any affected holes where you can get at both sides, using a model-makers drill, and feed a thin wire through the hole, soldering to the nearest piece of undamaged track on the run to the hole, on both sides. If you can tell me the model number of the CD player, I might have the manual, or a similar one that we can use to determine exactly to where each cap is ultimately connected. I have done many of these over the years, though not so many recently, as they are getting old now. They are definitely always repairable in the end, but require much patience to repair the damage caused, and may cause you more than a little frustration along the way ... Arfa |
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