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Success Stories If you have successfully repaired or restored a piece of equipment, why not write up what you did and post details here. Particularly if it was interesting, unusual or challenging. PLEASE DO NOT POST REQUESTS FOR HELP HERE! |
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21st Nov 2016, 6:27 pm | #1 |
Heptode
Join Date: Nov 2008
Location: North Walsham, Norfolk, UK.
Posts: 899
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Technics SL-Q30 Direct Drive Turntable
This has been sitting around for ages but I got round to playing with it today.
The fault was when you powered it up it made a hummy noise and ran slowly backwards pulsing the drive in sympathy with the hum. I looked close at the 2 hall effects and saw one had some very tiny bulges on the top. Quick look in the spares pile revealed an old JVC linear tracker with broken cabinet and direct drive turntable so i stripped it to find the halls were 4 pin out of one end like a transistor unlike the technics where they emerge from each end like an IC, also no pinout information available in the service manual but with nothing to lose I connected it up, same symptoms so I rotated it 180 degrees, still no effect I then turned it over re-soldered it in stuck the platter on top and was amazed to find it running and at the correct speed. What a result, just goes to show they are quite robust devices as you can insert them the wrong way round and wrong way up !! |
21st Nov 2016, 7:34 pm | #2 |
Heptode
Join Date: Sep 2013
Location: Manchester, UK.
Posts: 860
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Re: Technics SL-Q30 Direct Drive Turntable
The repairs you don't expect to work are always the sweetest when they do!
Regards, Paul
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...No, it's not supposed to pick up the World Service, it's not a radio! |
22nd Nov 2016, 12:16 pm | #3 |
Dekatron
Join Date: Aug 2006
Location: Madrid, Spain / Wirral, UK
Posts: 7,484
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Re: Technics SL-Q30 Direct Drive Turntable
Wonder what caused that sensor to fail? I'd associate bulges with some short/overheating, I would have thought though that the voltages used in such a circuit would be negligible....
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Regards, Ben. |
22nd Nov 2016, 12:55 pm | #4 |
Nonode
Join Date: Jun 2008
Location: Coningsby, Lincolnshire, UK.
Posts: 2,814
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Re: Technics SL-Q30 Direct Drive Turntable
Nice work! I've got a Sony PS-Q7 on the to do pile with a dead hall sensor, I tried some from computer fan motors, bit they just were not right! Borrowed one from one of my Technics Sl-5's and it ran fine, one day it'll get fixed!
Regards, Lloyd |
22nd Nov 2016, 8:45 pm | #5 |
Heptode
Join Date: Nov 2008
Location: North Walsham, Norfolk, UK.
Posts: 899
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Re: Technics SL-Q30 Direct Drive Turntable
Ben, I think it had been got at as there were a few screws missing and the hals are open to the world so if the platter was put on with it powered it might just have been shorted by the metal centre spindle
Hi Lloyd I have done a bit of research and I think the one I used is one of these http://www.allegromicro.com/en/Produ...hes/A1233.aspx and they show as still available |