For the Eagle Term II v1.9 Sourcecode I had to repair and recap a SFD-1001 drive.

A very common issue on these drives are leaking capacitors causing damage on the motor control PCB. These should be replaced as soon as possible.

A few important notes on the way:
1. The screws holding the rotor(magnet) and especially the PCB screws are ridiculously tight, it’s almost as they are not loosening up at all. Make sure to have an exact size screwdriver and use correct amount of force to unscrew them, you don’t want to end up with destroyed screw heads.
2. There is a fragile flat cable on the underside, be aware of it before lifting up the PCB.


Remove the three screws and lift the rotor(magnet).


Remove the four screws holding the PCB marked with red circles and remove the spacers (mine had three of them).


Desolder the two connectors marked with red squares.


Close up of the cable in the lower left corner, be careful desoldering it.


Drive motor control PCB.


Position Quantity Value Dimension(mm)
C01/C02 2 22 uF 10V h=7,5 d=5,2 r=2
C03/C17 2 4.7µF 25V h=7,5 d=4,2 r=2
C05/C09 2 0.47µF 50V h=7,2 d=4,2 r=2
C10 1 47µF 10V h=7,7 d=6,5 r=2,5
C12 1 33µF 25V h=7,7 d=6,5 r=3
C13/C14/C15 BIPOLAR 3 10µF 25V h=11 d=5,2 r=2

Original capacitor values and sizes. h=height, d=diameter, r=lead spacing.


Position Quantity Value DigiKey # Manufacturer Manufacturer #
C01/C02 2 22 uF 16V P15790CT-ND Panasonic EEA-GA1C220B
C03/C17 2 4.7µF 50V P15838CT-ND Panasonic EEA-GA1H4R7B
C05/C09 2 0.47µF 50V 493-10466-1-ND Nichicon UMA1HR47MDD1TP
C10 1 47µF 10V P14478-ND Panasonic EEA-GA1A470
C12 1 33µF 25V P15805CT-ND Panasonic EEA-GA1E330H
C13/C14/C15 BIPOLAR 3 10µF 50V P1280-ND Panasonic ECE-A1HN100U

Component list and manufacturer part numbers, some caps are rated higher than the original voltage value. There is limited space for the capacitors but the components above will fit. Capacitors C13/C14/C15 are bipolar.


Description DigiKey # Note
24 Position Connector SCSI Through Hole, Right Angle Solder 1024RFA-ND ZoomFloppy
24 Position Plug Connector SCSI Through Hole Solder 1024PMA-ND  

Part numbers / IEEE-488 Connectors also available from DigiKey.



SFD-1001 Head Resistance check.

Resistance RW1 or RW2 to CT : 37 ± 30% Ohms
Resistance ERASE to CT : 8.0 ± 30% Ohms
Information above from 8250LP SFD-1001 Disk Drive Technical Manual


RED-WHT 18 19,5  
RED-BLK 36 37  
RED-GRN 21 21,6  
GRN-BLK 22 22  
GRN-WHT 4 4,5  
BLK-WHT 20 19.1  

Measurements from the field on working drives for reference.