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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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old turntables
alright i have a very old turntable that was probably made in the late
1960s. whenever i play a record the needle always stops moving on the record, usually in the middle of the last song. i have tried other records but it always stops in the same place. it feels like there is a spring mechanism that keeps it from moving in all the way in. so my question is what is causing this to happen, and how can i fix it. just please dont tell me to buy one of these new ones. |
#2
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old turntables
In article .com,
dallie wrote: alright i have a very old turntable that was probably made in the late 1960s. whenever i play a record the needle always stops moving on the record, usually in the middle of the last song. i have tried other records but it always stops in the same place. it feels like there is a spring mechanism that keeps it from moving in all the way in. so my question is what is causing this to happen, and how can i fix it. just please dont tell me to buy one of these new ones. On some types the arm touches a lever at the end of a record which then triggers a lift mechanism. Make sure that lever is free moving. Could also be problems with the arm bearings, bias compensation, or incorrect tracking weight. -- *I'm out of my mind, but feel free to leave a message. Dave Plowman London SW To e-mail, change noise into sound. |
#3
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old turntables
"dallie" wrote in message oups.com... alright i have a very old turntable that was probably made in the late 1960s. whenever i play a record the needle always stops moving on the record, usually in the middle of the last song. i have tried other records but it always stops in the same place. it feels like there is a spring mechanism that keeps it from moving in all the way in. so my question is what is causing this to happen, and how can i fix it. just please dont tell me to buy one of these new ones. Could be a jammed auto-changer trigger. |
#4
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old turntables
"Dave Plowman (News)" writes:
In article .com, dallie wrote: alright i have a very old turntable that was probably made in the late 1960s. whenever i play a record the needle always stops moving on the record, usually in the middle of the last song. i have tried other records but it always stops in the same place. it feels like there is a spring mechanism that keeps it from moving in all the way in. so my question is what is causing this to happen, and how can i fix it. just please dont tell me to buy one of these new ones. On some types the arm touches a lever at the end of a record which then triggers a lift mechanism. Make sure that lever is free moving. Could also be problems with the arm bearings, bias compensation, or incorrect tracking weight. Most likely gummed up grease on any or all of those parts. --- sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/ Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/ +Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm | Mirror Sites: http://www.repairfaq.org/REPAIR/F_mirror.html Important: Anything sent to the email address in the message header above is ignored unless my full name AND either lasers or electronics is included in the subject line. Or, you can contact me via the Feedback Form in the FAQs. |
#5
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old turntables
ian field wrote:
"dallie" wrote in message oups.com... alright i have a very old turntable that was probably made in the late 1960s. whenever i play a record the needle always stops moving on the record, usually in the middle of the last song. i have tried other records but it always stops in the same place. it feels like there is a spring mechanism that keeps it from moving in all the way in. so my question is what is causing this to happen, and how can i fix it. just please dont tell me to buy one of these new ones. Could be a jammed auto-changer trigger. Could be wires bound up underneath or bad tonearm bearing(s)... Mark Z. |
#6
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old turntables
dallie wrote: alright i have a very old turntable that was probably made in the late 1960s. whenever i play a record the needle always stops moving on the record, usually in the middle of the last song. i have tried other records but it always stops in the same place. it feels like there is a spring mechanism that keeps it from moving in all the way in. so my question is what is causing this to happen, and how can i fix it. just please dont tell me to buy one of these new ones. if its an autochanger (such as a garrard or bsr), unclip the turntable's central c-ring/ clip and remove the platter itself by lifting straight up. Look for a large metal toothed cam. unclip the c-ring carefully, and lift off the cam. you may feel resistance, thus revealing the problem: gummed up due to dried grease. More importantly, there will probably be a smaller set of moving plates affixed to this cam which will need checking and removing. I have usually found it best to remove these parts, clean the bearings and any shafts with alcohol and a q tip then regrease (NOT wd40!!). hope this helps, let us know how it all goes. -Ben. |
#7
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old turntables
ian field wrote:
"dallie" wrote in message oups.com... alright i have a very old turntable that was probably made in the late 1960s. whenever i play a record the needle always stops moving on the record, usually in the middle of the last song. i have tried other records but it always stops in the same place. it feels like there is a spring mechanism that keeps it from moving in all the way in. so my question is what is causing this to happen, and how can i fix it. just please dont tell me to buy one of these new ones. Could be a jammed auto-changer trigger. Could be wires bound up underneath or bad tonearm bearing(s)... Mark Z. I think Sam and a couple of others nailed it. Grease drys up and makes things bind. The lever which trips the 'rejuct' mech' on those old changers is definitely suspect; but I imagine the rest of the guts are just as gummy. For a novice, these are not the easiest things to work on. The timing of the cams is similar in some ways to a VCR. Get it wrong upon reassembly, and it won't work. jak |
#8
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old turntables
dallie:
If you are mechanically inclined in the least, you should be able to LOOK at the mechanism under the platter and on the underside of the turntable and SEE what is hanging up. As others have indicated, could as simple as dried up grease causing stiff bearings and spindles, stuck or sluggish cam and levers, stuck end of record trigger mechanism, and possibly bent levers, etc. You should be able to move the arm around and determine what the problem is. You would be very wise to remove the expensive needle (stylus) while analysing this problem so you don't accidently damage it. If you are still not certain how to proceed with this repair you should TAKE it to a repair shop that services this type of item.... my shop does... and many smaller, owner operated shops will still do this kind of work....... if you screw it up more than it already is, the repair cost could be much higher. electricitym .. .. |
#9
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old turntables
Mechanical problem is very likely, but if not, then I would guess dried
out electrolytic caps. Although there aren't as much cap problems in 60's turntables as in today's motheroards :-) But 40 years may be too much for some of them.. If the motor runs on dc, and mechanics naturally have more "resistance" on the point where it jams, it increases the load and the ripple voltage increases on that point, and the motor doesn't get enough effective voltage to work. This is, however, just a kind of hypothesis, and actually an unlikely reason if there isn't other symptoms (e.g. humming noise on output etc.) |
#10
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old turntables
jakdedert writes:
ian field wrote: "dallie" wrote in message oups.com... alright i have a very old turntable that was probably made in the late 1960s. whenever i play a record the needle always stops moving on the record, usually in the middle of the last song. i have tried other records but it always stops in the same place. it feels like there is a spring mechanism that keeps it from moving in all the way in. so my question is what is causing this to happen, and how can i fix it. just please dont tell me to buy one of these new ones. Could be a jammed auto-changer trigger. Could be wires bound up underneath or bad tonearm bearing(s)... Mark Z. I think Sam and a couple of others nailed it. Grease drys up and makes things bind. The lever which trips the 'rejuct' mech' on those old changers is definitely suspect; but I imagine the rest of the guts are just as gummy. For a novice, these are not the easiest things to work on. The timing of the cams is similar in some ways to a VCR. Get it wrong upon reassembly, and it won't work. Just don't disasemble beyond removing the platter. Most of the other stuff can be cleaned in-place. --- sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/ Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/ +Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm | Mirror Sites: http://www.repairfaq.org/REPAIR/F_mirror.html Important: Anything sent to the email address in the message header above is ignored unless my full name AND either lasers or electronics is included in the subject line. Or, you can contact me via the Feedback Form in the FAQs. |
#11
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old turntables
Mechanical problem is very likely, but if not, then I would guess dried
out electrolytic caps. What? If this were an electronic problem I'd understand thinking it was a cap but this problem is totally mechanical. If the motor runs on dc, and mechanics naturally have more "resistance" on the point where it jams, it increases the load and the ripple voltage increases on that point, and the motor doesn't get enough effective voltage to work. I'm guessing you've never played with a turntable. There isn't a motor guiding the needle. The turntable turns and the resistance of the grooves in the record guide the needle inward. I'd have to agree with everyone else in saying that this is probably dried out grease or a mechanical failure. - Mike wrote in message oups.com... Mechanical problem is very likely, but if not, then I would guess dried out electrolytic caps. Although there aren't as much cap problems in 60's turntables as in today's motheroards :-) But 40 years may be too much for some of them.. If the motor runs on dc, and mechanics naturally have more "resistance" on the point where it jams, it increases the load and the ripple voltage increases on that point, and the motor doesn't get enough effective voltage to work. This is, however, just a kind of hypothesis, and actually an unlikely reason if there isn't other symptoms (e.g. humming noise on output etc.) |
#12
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old turntables
In article ,
Michael Kennedy wrote: I'm guessing you've never played with a turntable. There isn't a motor guiding the needle. There were a few which had parallel tracking motor driven pickups. B&O and Revox, to name but two. -- *If at first you do succeed, try not to look too astonished. Dave Plowman London SW To e-mail, change noise into sound. |
#13
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old turntables
On 7 May 2006 10:16:20 -0700, "dallie"
wrote: alright i have a very old turntable that was probably made in the late 1960s. whenever i play a record the needle always stops moving on the record, usually in the middle of the last song. i have tried other records but it always stops in the same place. it feels like there is a spring mechanism that keeps it from moving in all the way in. so my question is what is causing this to happen, and how can i fix it. just please dont tell me to buy one of these new ones. If you post the name and model number of the turntable, I should be able to send you a step by step repair procedure. Chuck |
#14
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old turntables
Dave Plowman (News) spake thus:
In article , Michael Kennedy wrote: I'm guessing you've never played with a turntable. There isn't a motor guiding the needle. There were a few which had parallel tracking motor driven pickups. B&O and Revox, to name but two. As the O.P. said this was a turntable from the 1960s, it is undoubtedly a simple mechanical device, with a synchronous induction motor with no associated electronics, and certainly no servo-operated tonearm. I'd be willing bet money on it. The previous poster's (or a couple back) speculation was only that. -- Pierre, mon ami. Jetez encore un Scientologiste dans le baquet d'acide. - from a posting in alt.religion.scientology titled "France recommends dissolving Scientologists" |
#15
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old turntables
In article ,
David Nebenzahl wrote: I'm guessing you've never played with a turntable. There isn't a motor guiding the needle. There were a few which had parallel tracking motor driven pickups. B&O and Revox, to name but two. As the O.P. said this was a turntable from the 1960s, it is undoubtedly a simple mechanical device, with a synchronous induction motor with no associated electronics, and certainly no servo-operated tonearm. I'd be willing bet money on it. Oh I'd agree. The previous poster's (or a couple back) speculation was only that. Well, yes. But where would newsgroups be without pedantry? -- *Gargling is a good way to see if your throat leaks. Dave Plowman London SW To e-mail, change noise into sound. |
#16
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old turntables
The previous poster's (or a couple back) speculation was only that. Well, yes. But where would newsgroups be without pedantry? Very True... :-) - Mike |
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