Technics SL-P990 disc wont spin unless i help it ..

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For anyone still looking for a fix to the p990, yesterday i got fixed a japanese import model (all black really cool). The IC was blown so i replaced the complete motor with the one of a P520, it wont physically fit without resoldering the bigger caps that are on a separate PCB in another position and removing the alignment pins on the p990 mechanism, also the connector is different but you can re use the original wiring, it uses the same cables colors.
Also disc height might need a recalibration.
On a side note every SOALP1200 machine is a good donor for them (check vasiltech for the models) it is strongly recommended that the new motor also gets a recap. Also Soalp320 motor might be compatible too, i'm actually looking for one to use it on a second p990 with the same failure
 
Thats diffferent PC91, a new mechanism, you have another P990 with the same failure , is s shame, but I think the problem is more common that i thought

Yes, different but schematically the same if the mounting points are in the same place it can work.

P520 also had a very different mechanism but with little effort it was alive.

Also yes... is quite a common problem on the 990 but not so much on the other donor mechanisms
 
least there is another fix for the P990 mechanism with the P520 donoars. It must be the P990 IC that must fail, its good and brushless design but is let down with the IC

I think the problem is center on the capacitors brand/model on the P990 that don't hold very well to time and leaks.

There are small SMD caps which ail in every technics model that has brushless but this won't kill the IC.

On the other hand there are 3 big caps on the motor, on the p990 the leak in a very nasty way stressing the IC and making it fail.
On other models this caps are from other brands and in the Soalp1200 mechanism is even on a different PCB which completely avoids leaking damage
 
This is what it looks like in the SL-P1200: IMG_20190303_16402.jpg
 
Thanks for the photo MrSnapper, i bet there is not many P1200 with mech issues with the heatsink of the motor chip, if only they had it on the P990 which was a high end player for home use.

I got a spare board but if find a chip working someday will instal heatsink on it
 
Hello Mr Snapper, That is a shame about being banned. I havent questioned his authority though.

Thanks Snapper, the P990 currently has nice upgrades with silmicII, wima and pano fm in the digital power supply section and output caps are some old obbligato 3.3uf caps. i dare not touch the opamps, but it they are not bad, changed a few resistors on the output to CMFs

The V9 phono is here. I fear changing the internal cable could bring crosstalk again, used a lovely cheap cable on the V8s
https://www.diyaudio.com/forums/analogue-source/337648-technics-amplifier-phonostage-film-cap-opamp.html
 
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