What would cause a number 3 to appear on sportcraft ts400 after just a few seconds

Motor run-away due to shorted windings in the motor. Take to a motor repair facility

https://www.google.com/search?q=Sportcraft+tx400+motor


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https://youtu.be/qmCz9yiPhlk

If you wish to get some details treadmill repair and error code ; check the site linked here. Pull up older posts.
http://electro-medical.blogspot.com/

This Part is no longer available.

www.atlantafitnessrepair.com

http://www.lsengineers.co.uk/media/pdfs/stihl/ts400-disc-cutter-spares.pdf

here is the PDF File

1) LUBE THE DECK BELT, this produce enough friction for shutdown the machine.
2) LUBE the rollers bearing very well.
3) Test the input voltage motor, if there are VOLTAGE, the motor need repair.
4) Test the output voltage board, for input voltage motor, if there are NOT the board is faulty.
See the block diagram. God bless you

you have a broken spinner. Take hte motor cover off and look on the opposite side of the motor. there will be a partof the spinner wheel there. I have yet to find a way to short cirut the connectors nor a replacement wheel.

Contact the manufacturer. You need the optical disc. It is the speed sensor. Eric For Treadmill replacement parts, please contact our Consumer Affairs Dept. at (800) 526 - 0244

Sorry I dont have the solution but I have the same problem.
Read somewhere that Sportcraft control boards had
a design flaw.

To setup the phone to automatically insert your external dial group (usually '0') before numbers, so you can save them in your phone book, and make calls from your missed / received call logs, you should check the TS400 manual.
For the TS350i you do this 1) press transfer/menu button 2) Press 4 - Call preferences menu 3) Press 8 - Access Code Prefix 4) Enter the number you use for outgoing calls (usually 0) 5) Press OK