Speed queen cts99awn won't spin fast

[Kado]

I just bought a used speed queen CTS99AWN (Manufactured 2006) stackable washer and dryer and it works great up until the rinse and spin cycles. 
   During the fill and wash cycles the drum agitates the clothes 15 seconds clockwise, rests for 9 seconds, and the spins 15 seconds counter-clockwise as it should. However, during the rinse cycles the drum spins for 20-30 seconds at 500rpm and then stops and doesn't spin the rest of the rinse or spin cycle. The rinse function continues as it should, filling with water and pumping it out, followed by the spin cycle with the pump turning on but again it does not spin. The motor leads ohms resistance are within range so the motor is good. Indicator LEDs show NO error codes being generated, the washing machine technically doesn't know that it's not spinning in the rinse and spin cycles. 
    My question is, does the machine control tell the motor control inverter what to do? Is this a problem with my machine control unit or motor control inverter unit? Thank you for any help!

-Steven K

ps. Belt is in good shape and wiring all looks brand new under the washer. Door switch is fully functional. 

[evaappliance]

http://pchome.alliancels.net/manuals/PartsService/802108.pdf?635944861552438000

see if you can open this link , hope it helps !

[Kado]

Thank you Evaappliance, I've read it cover to cover already. It has all the service procedures which is awesome, but limited troubleshooting for the washer. It decribes fatal error codes and my machine is no giving me any fatal error codes. The closest thing that's related is: 

"If the control receives the motor failure signal from the motor control, the control will enter Error Mode. The control will turn off all outputs and flash the DOOR and FINAL SPIN LEDs one second on/one second off to indicate a motor failure error. This is a fatal error. The machine must be unpowered to clear this error."

There is no error code. Another thing it could be is: 

"motor will not run-door and final spin led flashing"

check motor continuity- if YES replace motor control, if NO replace motor.

We checked the motor and it's fine. Also the lights were not flashing. Which leads me to believe it could be either the motor control or the machine control. What's most likely the culprit? I've read online that when front loaders don't spin it's because of the motor control. However my machine spins nice and smoot and quiet during agitation. Thank you

[evaappliance]

I'm thinking , check the out of balance switch first , then if that is ok , replace the motor control board,  this is just my opinion  

[Kado]

Is there a way to check the balance switch with the unit unplugged? What am I looking for on my meter? Thank you!

[Kado]

11 minutes ago, Kado said:

Is there a way to check the balance switch with the unit unplugged? What am I looking for on my meter? Thank you!

I did a little research. I'm guessing it should read 0 ohms resistance correct? 

[Kado]

44 minutes ago, Kado said:

I did a little research. I'm guessing it should read 0 ohms resistance correct? 

I got 0.1 ohms jumping around to 0.4.  I'm going to test run it with a jumper tomorrow and see if that's works. Thanks Evaappliance. Happy Easter! 

[Hiroshi]

many units will not spin at full speed according to control selections.... 500 rpm may be correct on "delicate." Does it spin slowly on all settings?