technics sp 10
yes it did the same thing. only this one has lost its stop/start control and i cant seem to get this back. as a matter of fact i am totally bewildered as to how this start/stop button controls the brake on this unit. the wiring from the start/stop switch goes directly to a remote jack input. it has no connection to theinternal parts of the turntable. it appears as if it to send a signal to the tone arm at some remote location. there is no way for this signal to return to the turntable anyway. i am baffled. the customer assures me he has been turning the unit off and on using this button. any info on this would be appreciated.
as for the chips, again i am not yet at work where i will right down the chip numbers i changed, but they are located in two rows on the speed control board. the ones i changed can be described as the last four chips to the right on row 'b'.
this might not compute from me to you so tonight i will give you the numbers
yes it did the same thing. only this one has lost its stop/start control and i cant seem to get this back. as a matter of fact i am totally bewildered as to how this start/stop button controls the brake on this unit. the wiring from the start/stop switch goes directly to a remote jack input. it has no connection to theinternal parts of the turntable. it appears as if it to send a signal to the tone arm at some remote location. there is no way for this signal to return to the turntable anyway. i am baffled. the customer assures me he has been turning the unit off and on using this button. any info on this would be appreciated.
as for the chips, again i am not yet at work where i will right down the chip numbers i changed, but they are located in two rows on the speed control board. the ones i changed can be described as the last four chips to the right on row 'b'.
this might not compute from me to you so tonight i will give you the numbers
Technics SP-10
If you have a Technics SP-10 with speed or switching problems, contact Wendell at Soundcom Electronics in San Antonio, Texas. He has patiently and with determination, wrung out the problems I mentioned in an earlier post. The platter spun very fast and the start switch had no effect. Wendell found faulty ICs, and managed to locate replacements, since Panasonic no longer stocks parts. The SP-10 is a fantastic, stable, rock-solid turntable, and kudos to Wendell for his tenacity in tracking down the problem. By the way, I think the ICs fried because the caps in the power supply went bad. I am now going to shotgun the power supply caps every 5 years whether they need it or not.
rollinr
If you have a Technics SP-10 with speed or switching problems, contact Wendell at Soundcom Electronics in San Antonio, Texas. He has patiently and with determination, wrung out the problems I mentioned in an earlier post. The platter spun very fast and the start switch had no effect. Wendell found faulty ICs, and managed to locate replacements, since Panasonic no longer stocks parts. The SP-10 is a fantastic, stable, rock-solid turntable, and kudos to Wendell for his tenacity in tracking down the problem. By the way, I think the ICs fried because the caps in the power supply went bad. I am now going to shotgun the power supply caps every 5 years whether they need it or not.
rollinr
I've had older Sony TTs with this problem....
and found 2 basic problems, some of which have been refered to in prior posts:
* Power Supply problems
At this age, many of the nicer Direct Drive TTs will have power supply caps that need to be replaced. Some of these can begin to cost a bit if you need to have a tech do the work as there are many involved and the bench time will not be short.
Other problems in the power supply that I've seen are:
- Operating voltages floating just outside of spec. That is, the 5v line was wandering just far out that the regulator would fall out of regulation, causing the related circuits to loose their lock. Definitely a digital-type of problem.
* Feedback problems
The biggest problem I've seen are in the feedback sensor itself. Most problems have been related to:
- Sensor adjustment to the platter's magnetic ring. I've seen some rings on platters that have lost sufficient magnetic potency that the feedback loop is interrupted. I suspect that, at some point, the platter was exposed to a strong-enough field of magnetism that it was essentially erased much like a tape demagnetizer works its magic on a tape. This is confirmed by adjusting the sensor as best as can be, then watching to see if the speed problem is related to platter rotation.
- Dirty sensors.
I've seen dust and grunge buildup on the sensors that needed to be cleaned out - most due to having been sitting long periods without a dust cover or in a really dirty place (think: back store rooms of old discos).
Hope that helps.
Cheers,
David
and found 2 basic problems, some of which have been refered to in prior posts:
* Power Supply problems
At this age, many of the nicer Direct Drive TTs will have power supply caps that need to be replaced. Some of these can begin to cost a bit if you need to have a tech do the work as there are many involved and the bench time will not be short.
Other problems in the power supply that I've seen are:
- Operating voltages floating just outside of spec. That is, the 5v line was wandering just far out that the regulator would fall out of regulation, causing the related circuits to loose their lock. Definitely a digital-type of problem.
* Feedback problems
The biggest problem I've seen are in the feedback sensor itself. Most problems have been related to:
- Sensor adjustment to the platter's magnetic ring. I've seen some rings on platters that have lost sufficient magnetic potency that the feedback loop is interrupted. I suspect that, at some point, the platter was exposed to a strong-enough field of magnetism that it was essentially erased much like a tape demagnetizer works its magic on a tape. This is confirmed by adjusting the sensor as best as can be, then watching to see if the speed problem is related to platter rotation.
- Dirty sensors.
I've seen dust and grunge buildup on the sensors that needed to be cleaned out - most due to having been sitting long periods without a dust cover or in a really dirty place (think: back store rooms of old discos).
Hope that helps.
Cheers,
David
SP10 problems
I had this problem since some time now, and tried everything on the circuit boards, but nothing seemed to work. I then bought another off ebay, and when I got that, I changed boards one by one to see which was faulty, and ALL THE BOARDS WORKED FINE. That leaves the motor assembly, which also contains the feedback sensor.
For the question on the brakes, when the table is stopped 2 things happen, i.e. it applies a reverse force on the motor, AND at the same time activates a solenoid which in turn tightens the brake pad belt around the circumference of the motor. The solenoid can gum up, and a little WD40 sprayed on this can help, but be sure not to get any on the felt pads.
Hope this helps some of you out there who may be struggling with similar problems, 'cause there seem to be many. I spent a lot of wasted hours working on the circuit boards, when the problem was in the motor all this time. Would have never guessed it if I didn't have another for comparison.
I had this problem since some time now, and tried everything on the circuit boards, but nothing seemed to work. I then bought another off ebay, and when I got that, I changed boards one by one to see which was faulty, and ALL THE BOARDS WORKED FINE. That leaves the motor assembly, which also contains the feedback sensor.
For the question on the brakes, when the table is stopped 2 things happen, i.e. it applies a reverse force on the motor, AND at the same time activates a solenoid which in turn tightens the brake pad belt around the circumference of the motor. The solenoid can gum up, and a little WD40 sprayed on this can help, but be sure not to get any on the felt pads.
Hope this helps some of you out there who may be struggling with similar problems, 'cause there seem to be many. I spent a lot of wasted hours working on the circuit boards, when the problem was in the motor all this time. Would have never guessed it if I didn't have another for comparison.
Problems with my Technics SP-10 MK2
I have a Technics SP-10 MK2 turntable that is having a lot of problems. Immediately after buying this turntable I did a complete electrolytic recap of both the turntable and the power supply. I have been working on my own audio equipment for over 50 years and I found it a very simple process to replace all these caps. When I got the turntable the strobe light was out and it ran very fast when first started but eventually slowed down and ran at close to right speeds on all speeds. After I recapped the power supply and turntable the strobe light started working again and the turntable started up at the correct speeds right away. The strobe showed it at speed in way less than 1/2 turn of the platter. It ran this way for a week or so and then all of a sudden the strobe light went off. Then the speeds started to be irradic again and then the turnable just stopped working and was blowing the 1 amp 125 volt fuse. I checked the voltages on the power supply at the plug and I only saw a voltage of 156 volts at one of the pins of the plug. Inside the power supply I could find 56 volts in the place of what should have been the 32 volt section and the 156 volts that was on one pin at the plug. I couldn't find the 5 volts anywhere at all. This one is really messing with my mind. I have checked job I did of the replaced caps over and over and all of them have been installed correctly in regards to polarity and value. I guess I first need to find out why I don't have the 3 voltages the turntable needs at the plug but again, I have checked the values and polarities of all the replaced caps and they are right. Does anyone out there have any ideas as to what is going on? HELP!!!
I have a Technics SP-10 MK2 turntable that is having a lot of problems. Immediately after buying this turntable I did a complete electrolytic recap of both the turntable and the power supply. I have been working on my own audio equipment for over 50 years and I found it a very simple process to replace all these caps. When I got the turntable the strobe light was out and it ran very fast when first started but eventually slowed down and ran at close to right speeds on all speeds. After I recapped the power supply and turntable the strobe light started working again and the turntable started up at the correct speeds right away. The strobe showed it at speed in way less than 1/2 turn of the platter. It ran this way for a week or so and then all of a sudden the strobe light went off. Then the speeds started to be irradic again and then the turnable just stopped working and was blowing the 1 amp 125 volt fuse. I checked the voltages on the power supply at the plug and I only saw a voltage of 156 volts at one of the pins of the plug. Inside the power supply I could find 56 volts in the place of what should have been the 32 volt section and the 156 volts that was on one pin at the plug. I couldn't find the 5 volts anywhere at all. This one is really messing with my mind. I have checked job I did of the replaced caps over and over and all of them have been installed correctly in regards to polarity and value. I guess I first need to find out why I don't have the 3 voltages the turntable needs at the plug but again, I have checked the values and polarities of all the replaced caps and they are right. Does anyone out there have any ideas as to what is going on? HELP!!!
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