Tektronix 556 Fan Motor Repair Part 2

In this continuation of Tektronix 556 Fan Motor Repair Part 1, I have removed the motor and mount assembly and disassembled it.  Now I need to figure out the problem and rebuild the motor.

Tektronix 556 Fan Motor Overview, mounted in place

556 Fan Motor Rear

Tektronix 556 Fan Motor removed from mounts.  The Tektronix part number is 147-0029-00.

Tektronix 556 Fan Motor

Tektronix 556 Fan Motor removed from mounts.

Tektronix 556 Fan Motor

Tektronix 556 Fan Motor removed from mounts.

Tektronix 556 Fan Motor

The next few images show the disassembled parts of the motor:

Rotor, end bells and bushing assembly

556 Bushing Assemblies and Rotor

End bell inside, retainer, spring washer felt and bushing.

556 Fan Motor Bushing Assembly

End bell and bushing assembly

556 Bushing Assembly

Rotor and spacers

556 Fan Motor Shaft … Read More »

Tektronix 556 Fan Motor Repair Part 1

I was recently fortunate enough to acquire a Tektronix 556 Dual Beam Oscilloscope with many accessories and in good condition.  Unfortunately, the cooling fan on the scope was very loud and more concerning, it emitted an alarming metal on metal contact sound.  After verifying basic operation of the oscilloscope, I decided to repair the cooling fan.  This process is documented in the images and commentary that follow.

Part 1: Removing the Noisy Fan Motor

556 Cooling Module with filter and mesh screen removed.  The fan is connected to the chassis wiring at the ceramic terminal which is circled:

556 Fan Cooling Module Outside

Fan to chassis wiring connection terminal.

556 Fan Cooling Module Fan Connections

Inside of cooling module and bottom side of motor (fan blade removed):

556 Fan Motor Underside

Back side of motor (fan blade … Read More »