Sportsmith Blog

No Resistance on the Stairmaster Stepmill 916

About This Video

This video covers the electronic troubleshooting for a complaint of No Resistance on the Stairmaster Stepmill 916.

Tools Needed: Multi Meter, Assistant for Testing Purposes

For more information about this video,a step by step guide, and parts click here.


SPORTSMITH™ Announces StairMaster® and Schwinn Fitness® Product Support Tech Center

Tulsa, OK – June 7, 2010 – SPORTSMITH™, the nation’s largest supplier of fitness equipment parts, today announced its alliance with StairMaster® and Schwinn Fitness®. Beginning June 1, 2010, the company will launch the Official Authorized Product Support Center, sourcing all non-warranty replacement parts and providing technical support worldwide for legacy StairMaster® and Schwinn Fitness® Models.

An additional 20,000 square feet of warehouse space accommodates its expanded parts selection. StairMaster® and Schwinn Fitness® non-warranty equipment owners will now receive around-the-clock service through the new StairMaster Product Support Center accessible at

Using this web portal, consumers may purchase replacement parts, view parts diagrams and watch repair tutorial videos. Live web-based technical support will also be available via online chat. Improved shipping rates have already been secured.

"This alliance allows us to better utilize our staff and focus on growing our business,” explains Dustin Grosz, StairMaster CEO. “We chose SPORTSMITH™ because of their vast knowledge of the StairMaster® and Schwinn Fitness® brands, including their innovative warehouse capabilities and same day shipping of fitness equipment parts and fitness products."

Moving forward, StairMaster™ will concentrate efforts on manufacturing and warranty services for existing business segments. “As the business grows, we are relying on SPORTSMITH™ to be the experts and manage the non-warranty aspects,” continues Grosz.

StairMaster® and Schwinn Fitness® models include:

StairMaster® Stepper Models

  • 4000PT
  • 4100PT
  • 4200PT
  • 4400CL
  • 4400PT
  • 4600CL
  • 4600PT
  • 7000PT StepMill
  • SC916 StairClimber
  • SM916 StepMill

Schwinn Fitness® Bike Models

  • AC Classic
  • AC Performance
  • AC Sport
  • IC Elite
  • IC Evolution
  • IC Evolution SR
  • IC Pro

With a 15-year legacy, SPORTSMITH™ is proud to be the nation’s leading product support company with a solid reputation within the fitness industry. The company has built its stellar reputation by consistently delivering world-class quality product support, efficient customer service and expert technical support. The company offers the most technologically advanced user-friendly website in the fitness industry.

"We are honored to be chosen by StairMaster® as the company’s preferred product support provider,” states Brad Schupp, President of SPORTSMITH™. “We’re ideally poised to add real value to the company’s existing operations. We’re driven to ultimately enhance the industry as a whole by helping organizations focus on their core strengths, whether that is manufacturing world-class exercise equipment, developing the finest fitness facility within their community  by making exercise equipment maintenance as fast, easy and cost efficient as possible. SPORTSMITH™ is a proven asset to the OEM manufacturers we work with and health clubs alike, that incorporate SPORTSMITH™ product support services within their business practices."

For more information, call 888-713-2880 or visit


Founded in 1995, SPORTSMITH™ is the nation’s largest supplier of fitness equipment and parts for health clubs and health-conscious individuals. The company is recognized for its superior quality, express same-day shipment on all orders, comprehensive selection of more than 40,000 individual items and overall value, with products 10 to 30 percent below competitive retail prices. The company serves customers through its 40,000 sq. foot state-of-the-art office warehouse, with orders placed by mail, fax, phone or online via its direct mail catalog and secure ecommerce website.


Electrical Troubleshooting for Stairmaster

Stairmaster 4600, 4400, & 4000PT Stairclimbers, among the most popular exercise machines sold on the market today, have three electrical components that are responsible for most troubleshooting calls.  The Alternator, Diode, and the resistor are the heart and soul of the Stairmaster 4600/4400PT Stairclimber and often cause resistance levels to drop creating performance problems.

Tools Needed:

7/16”, 3/8”, & 1/4” nut drivers. 4” piece of wire with alligator clips attached to each end, and a multi-meter,


The Stairmaster loses all resistance when you step onto the pedals.

Alternator Test:

First, remove the machine from its power source. Then remove the side panels so you have a clear view of the alternator. On the back of the alternator, remove the black wire from the terminal B+ (marked POS). Remove the brown wire from the field terminal. You will need a length of wire 4” long with alligator clips attached to each end of the wire. Attach the wire to the B+ (POS) terminal and the field terminal, step on the machine for 10-15 seconds; if full resistance is present, the alternator has correct current flow. If no resistance is present, the next item to check is the alternator brushes. The brown square plate with two machine screws is the cover to the brushes. Remove the two machine screws with a ¼” nut driver and remove the alternator brushes. There should be ¼” or more of brush, any less and the alternator brushes should be replaced first. If the proper amount of brush is available, replace the alternator.

Diode Test:

Remove the brown wire and diode from the field terminal of the alternator and set the multi-meter to the Ohms setting. Place one lead on each end of the diode, and then reverse the leads. A good diode will indicate a high reading in one direction and a lower reading in the opposite direction. Replace the diode if both readings are high or if both readings are low.

Resistor Test:

Remove one wire from the load resistor and place one lead from the multi-meter, one each threaded post on the resistor. If the multi-meter does not read 0.5 Ohms, replace the resistor.  As with any maintenance, procedures always consult your owners’ manual or seek the advice of a qualified repair technician.

Stairmaster Equipment Troubleshooting Videos