Good day everyone!
May I ask if anyone can help me with my SP10 Mk2?
I bought mine some 5 yrs ago, restored it physically and powder coated in black.
All electrolytic caps have been replaced on both the unit and the power supply. The PLL has also been tuned as per the Technics service manual. And it has worked flawlessly since then.
Along the way, I have collected some spares for the unit, it includes all the PCBs and the speed selection switches module. The spare PCBs have also been thru ECaps changed and PLL tuned to the current motor before being stored away.
Recently, the motor speed will go weird and speed up after playing for about half-hour, at all speeds, 33, 45, and 78. The next day, it behaves normal again, with speed locked solidly seen thru the platter strobe light. Then it went mad again after working for some 20mins. This intermittent fault will go on for days.
When this happens, the start/stop function will still work but the braking did not, it just decelerates slowly to a stop.
Then I changed out all the 4 PCBs inside, and the fault still behaves the same, working for some time before it speeds up again with vibration (cogging) on the unit. The next day it works for a while, then go crazy again...
I also change out the speed selector module from the spare set, still, the same fault exists!
Thinking it may have to do with the power supply unit 5vdc supply, I then built another new 5v and 32.5v power supply entirely, but the fault still remains.
Then I tested all the motor's coil winding for continuity, especially the FG coil. All tested good, no short, no opened circuit, with some ohmic values.
Now I m at a loss on what really happens here. Does anyone come across a similar experience on your set?
Please help me out, thanks!
May I ask if anyone can help me with my SP10 Mk2?
I bought mine some 5 yrs ago, restored it physically and powder coated in black.
All electrolytic caps have been replaced on both the unit and the power supply. The PLL has also been tuned as per the Technics service manual. And it has worked flawlessly since then.
Along the way, I have collected some spares for the unit, it includes all the PCBs and the speed selection switches module. The spare PCBs have also been thru ECaps changed and PLL tuned to the current motor before being stored away.
Recently, the motor speed will go weird and speed up after playing for about half-hour, at all speeds, 33, 45, and 78. The next day, it behaves normal again, with speed locked solidly seen thru the platter strobe light. Then it went mad again after working for some 20mins. This intermittent fault will go on for days.
When this happens, the start/stop function will still work but the braking did not, it just decelerates slowly to a stop.
Then I changed out all the 4 PCBs inside, and the fault still behaves the same, working for some time before it speeds up again with vibration (cogging) on the unit. The next day it works for a while, then go crazy again...
I also change out the speed selector module from the spare set, still, the same fault exists!
Thinking it may have to do with the power supply unit 5vdc supply, I then built another new 5v and 32.5v power supply entirely, but the fault still remains.
Then I tested all the motor's coil winding for continuity, especially the FG coil. All tested good, no short, no opened circuit, with some ohmic values.
Now I m at a loss on what really happens here. Does anyone come across a similar experience on your set?
Please help me out, thanks!
Bad news!
The FG magnet is broken in 3 places around the bolts.
I don't remember TT having any impact force on it, even during transportation, it has been working till it suddenly broke down during operation.
The only thing I can think of is the temperature change that caused the expansion/contraction of the 3 bolts. Still scratching my head!
Maybe it's time to convert to Thoren/Linn/Rega styled belt drive system, still using the awesome motor's bearing.
The FG magnet is broken in 3 places around the bolts.
I don't remember TT having any impact force on it, even during transportation, it has been working till it suddenly broke down during operation.
The only thing I can think of is the temperature change that caused the expansion/contraction of the 3 bolts. Still scratching my head!
Maybe it's time to convert to Thoren/Linn/Rega styled belt drive system, still using the awesome motor's bearing.
Attachments
Damn that's bad news.
The bearing in the SP10mk2 IMO is it's weakest point, the sleeve is a close slip fit and glued in NOT a press fit as I have almost all of the ones I have serviced come out when I have removed the ball. This is a poor design. The spindle is also 9/32 with a C clip under the rotor reducing bearing diameter further.
Maybe it's time to look into re-engineering the FG. A different FG would allow a larger spindle bearing.
Also motors come up on eBay occasionally
The bearing in the SP10mk2 IMO is it's weakest point, the sleeve is a close slip fit and glued in NOT a press fit as I have almost all of the ones I have serviced come out when I have removed the ball. This is a poor design. The spindle is also 9/32 with a C clip under the rotor reducing bearing diameter further.
Maybe it's time to look into re-engineering the FG. A different FG would allow a larger spindle bearing.
Also motors come up on eBay occasionally
this is an ordinary defect, I have seen several FG coils sunk near the screws indicating a start of fracture but they always worked.
If I remember correctly it seems to me that in this thread someone had refurbished a defective FG coil.
sure but the cost usually required for the engine alone has skyrocketed .... even $ 400 is required.