Hiho, It is quite possible that your speed "error" (if you want to call 200 rpm a mere error) is due to a leaky or deceased electrolytic. The best way to find that out is to replace the lytics with new ones. It really does not matter much what brand you use; all modern lytics will be an upgrade. Panasonic low voltage caps (FC type) are superb and cost a bit less than the ones Albert listed. I would start with the power supply. Disconnect it from the main chassis, turn it on, and measure the DC voltages at its outputs. (You'll need a manual, perhaps.) You should see 140VDC, 32VDC, and 5VDC with very little ripple (less than 1VAC, for example). If the voltages are only slightly off, and if there is acceptable ripple, then the supply is probably not to blame. There are pots inside the PS chassis with which you can re-adjust the DC outputs to conform to the expected values. OTOH, if voltages are way off or if there is significant AC voltage at the outputs, THEN you might change the caps first of all. If you have a cap meter, you can test each cap individually for leakage, or you can empirically change them all, because if they are not detectably bad now, they might soon be. There are only about 8 caps in there. If you can snag a service manual from Vinyl Engine or some other source, you can look up the parts list for the PS and simply order the ones you'll need. I bought my Panasonic caps from Digikey, I think, but there are other vendors, too. There is one high-voltage cap, maybe the 1000uF/80V in Albert's list. I actually used a 2000uF/200V Panasonic TS-ED type, because it exactly fits the clamp. It way outperforms the original. There's no harm in using a higher value in this position, but in other cases it's wise to use the same value in capacitance. The DC voltage rating can be the same as original or higher, but not lower. After you have checked out the PS, then turn your attention to the on-board electronics. This is a crapshoot, because it IS possible that one of the ICs has already blown, in which case you will be searching for it. I think Albert can help you there.
