Help
Hi All,
I scored a relatively cheap SP-10 MKII recently with the power supply. Upon receiving it, I unpacked it and plugged it up and the platter wasn't turning though the supply light and the 33 rpm light came ON. After opening the supply, I discovered that the 32V fuse was blown. So, I replaced it, and turned it on again. This time it blew the instant I flipped the switch. So, something is wrong there.
The other thing is that the platter is not spinning freely even when not powered. I read somewhere that this is by design--the mechanical brake is engaged to help with cueing. But I removed the brake and the motor still does not move freely. There is rubbing at several places. In other parts of the rotation it does move freely. Also, when I lift it up, it moves freely (I think though not 100% sure).
I'm trying to open the rear cover but I stripped one of the screws, so, I need to get that out before I can open it.
What are my next steps? Things to check? I have DMMs and have built some of Nelson's amps, so, I have confidence I can get this running. Just need some help figuring out what's going on. Do the motors on your SP-10s move freely when not powered?
Thanks!
Hi All,
I scored a relatively cheap SP-10 MKII recently with the power supply. Upon receiving it, I unpacked it and plugged it up and the platter wasn't turning though the supply light and the 33 rpm light came ON. After opening the supply, I discovered that the 32V fuse was blown. So, I replaced it, and turned it on again. This time it blew the instant I flipped the switch. So, something is wrong there.
The other thing is that the platter is not spinning freely even when not powered. I read somewhere that this is by design--the mechanical brake is engaged to help with cueing. But I removed the brake and the motor still does not move freely. There is rubbing at several places. In other parts of the rotation it does move freely. Also, when I lift it up, it moves freely (I think though not 100% sure).
I'm trying to open the rear cover but I stripped one of the screws, so, I need to get that out before I can open it.
What are my next steps? Things to check? I have DMMs and have built some of Nelson's amps, so, I have confidence I can get this running. Just need some help figuring out what's going on. Do the motors on your SP-10s move freely when not powered?
Thanks!
Mine runs freely with the power supply off. According to the service manual there is a small current when on that stops the platter from free movement.
If your is not moving freely when powered off, but does when the platter if lifted I would worry about the main bearing, and the (hopefully small ) possibility that you have damaged wiring in the motor
If your is not moving freely when powered off, but does when the platter if lifted I would worry about the main bearing, and the (hopefully small ) possibility that you have damaged wiring in the motor
RA7:
The solenoid that activates the brake is only on when the unit is powered. So it should spin freely when powered off. Sounds to me like you may have a problem with the damping material on the bottom of the platter coming loose and scraping on the motor. Take off the platter and inspect it. I had a similar problem, and just glued the damping back in place.
The fast blowing fuse, however, might indicate a problem with the drive electronics.
Mike
The solenoid that activates the brake is only on when the unit is powered. So it should spin freely when powered off. Sounds to me like you may have a problem with the damping material on the bottom of the platter coming loose and scraping on the motor. Take off the platter and inspect it. I had a similar problem, and just glued the damping back in place.
The fast blowing fuse, however, might indicate a problem with the drive electronics.
Mike
Thanks for the help so far, everyone! The rubbing is there even when the platter is removed and I spin just the motor with my hand, so, it is not the damping material below the platter.
I doubt it is the main bearing because I can feel it rub on near the outside rim of the motor. Could something have gotten in there during shipping?
Is it easy to remove the motor from the backside? I suspect not.
I doubt it is the main bearing because I can feel it rub on near the outside rim of the motor. Could something have gotten in there during shipping?
Is it easy to remove the motor from the backside? I suspect not.
Download the manual from Vinyl Engine.
You need to take the motor apart from the top. Completely remove the brake parts but not the solenoid. The small plate that you will see (page 17 bottom middle) has two black covers over its M3 screws, you need to break those cover/seals then undo the screws. Then just pull the motor rotating part out.
Dave
You need to take the motor apart from the top. Completely remove the brake parts but not the solenoid. The small plate that you will see (page 17 bottom middle) has two black covers over its M3 screws, you need to break those cover/seals then undo the screws. Then just pull the motor rotating part out.
Dave
The table was connected each time the fuse blew.
Re the motor: Thanks for the encouragement. I managed to take the motor apart. The seals were still on, so I presume it has never been opened or serviced before.
Now, here is the scoop: Shaft looks good and the bottom of the shaft also looks not too worn, just a tiny dimple in the center where it meets the ball bearing. When I drop it in, it traps air and during the period when it is dropping, it revolves really smoothly, but as soon as it drops all the way in, it starts rubbing. The coils look OK to me, and I can't figure out what it is rubbing against. Maybe the top hat rubs against the top of the bore. I suspect the ball has dropped far too low and that causes the rubbing. Curious to hear what others think.
Shaun, I'm not sure what you mean by a too-long screw that could stick into the motor. Can you elaborate? I don't think there are any screws to stick into the coils.
Re the motor: Thanks for the encouragement. I managed to take the motor apart. The seals were still on, so I presume it has never been opened or serviced before.
Now, here is the scoop: Shaft looks good and the bottom of the shaft also looks not too worn, just a tiny dimple in the center where it meets the ball bearing. When I drop it in, it traps air and during the period when it is dropping, it revolves really smoothly, but as soon as it drops all the way in, it starts rubbing. The coils look OK to me, and I can't figure out what it is rubbing against. Maybe the top hat rubs against the top of the bore. I suspect the ball has dropped far too low and that causes the rubbing. Curious to hear what others think.
Shaun, I'm not sure what you mean by a too-long screw that could stick into the motor. Can you elaborate? I don't think there are any screws to stick into the coils.
Just as an FYI (not to detract from ra7's woes): If you look carefully at the pics I posted, you will see some witness marks attesting to the fact that this motor had its bearing seized and in fact the bearing itself had been rotating inside the housing. You can see this on the platter just next to the spindle hole.
Thanks for the pics, Shaun! The coils on this motor and more golden in color, whereas yours appear to be more silver in color. Maybe that's just the enamel.
Looking for signs of rubbing, I see marks on the underside of the top of the motor, and some on the bottom face of the central ring with ribbed inside face (last picture in Shaun's post).
The only way the top rubs against the coils is if the shaft is falling far too deep into the bore, which would mean the ball bearing is slipping downward and is not snugly fitting into the bottom of the bore. Does that make sense? As I said before, until it falls all the way, it spins without problem.
I'm going to get a heat gun this evening and try to open the bottom part and see where the ball is.
Looking for signs of rubbing, I see marks on the underside of the top of the motor, and some on the bottom face of the central ring with ribbed inside face (last picture in Shaun's post).
The only way the top rubs against the coils is if the shaft is falling far too deep into the bore, which would mean the ball bearing is slipping downward and is not snugly fitting into the bottom of the bore. Does that make sense? As I said before, until it falls all the way, it spins without problem.
I'm going to get a heat gun this evening and try to open the bottom part and see where the ball is.
Thanks! The shaft appears attached to the platter on my motor, so I cannot see where the circlip rests. If I slip off the circlip, can I remove the shaft from the top of the platter?
Oh, and is there a technique to get the circlips back on? I struggled with one on the mechanical brake.
Edit: Last night, I got the ball bearing end open. The ball seems to be no lower than what I've seen in pictures. I didn't have time to pop it out yet.
Another thing I noticed was the metal rim on the outside of the circular magnet on the platter was sticking out below the platter rim for about one-half of the circle. You can see this rim in Shaun's 2nd to last picture very clearly. It's the one outside the magnet but inside the platter rim. After I tightened the screws holding the magnet and rim, and pushed the rim down (only somewhat) where it was sticking out, the rubbing seems to have stopped. I did that last night and it wasn't rubbing this morning. But who knows, it may return. Any one else have that experience with the rim sticking out?
Oh, and is there a technique to get the circlips back on? I struggled with one on the mechanical brake.
Edit: Last night, I got the ball bearing end open. The ball seems to be no lower than what I've seen in pictures. I didn't have time to pop it out yet.
Another thing I noticed was the metal rim on the outside of the circular magnet on the platter was sticking out below the platter rim for about one-half of the circle. You can see this rim in Shaun's 2nd to last picture very clearly. It's the one outside the magnet but inside the platter rim. After I tightened the screws holding the magnet and rim, and pushed the rim down (only somewhat) where it was sticking out, the rubbing seems to have stopped. I did that last night and it wasn't rubbing this morning. But who knows, it may return. Any one else have that experience with the rim sticking out?
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