Kenmore Ellite 110.70972990 doesn’t stay running

[JWill]

My push to start dryer doesn’t stay running. Cuts off immediately after button is released. I’ve checked the door switch, thermal fuse, thermistor, high limit thermostat, PTS relay, motor relay(even switched it out with the heat relay) and the Timer. There was some corrosion in the timer I’ve filed and cleaned the leads, they are making contact. At this point what’s left? I’m thinking it’s the even heat control board. Problem is.. this dryer is old and the board is hard to find not to mention expensive. Is there any way to bypass or perhaps replace a diode (which one)?  My control board is FSP 3976609

[16345Ed]

What about the motor itself? 

[MrApplianceMatt]

+1 for the motor. Run winding might be bad.

[MD8012]

I agree, most likely a motor.  But you do say that it quits as soon as you release the button. Are you saying that as long as you hold the start button in it will run?

Edited May 26, 2019 by MD8012

[Vance R]

+1 for motor. There is a centrifugal switch in the motor that when it comes up to speed make the path to neutral to keep it running.  The push to start switch is supposed to get the motor running, the centrifugal switch takes over to keep it going. If your inclined look at the fly weights on the motor shaft you see how they actuate the switch.

See second post below

Edited May 26, 2019 by Vance R
looked at schematic.

[MrApplianceMatt]

5 minutes ago, Vance R said:

+1 for motor. There is a centrifugal switch in the motor that when it comes up to speed make the path to neutral to keep it running.  The push to start switch is supposed to get the motor running, the centrifugal switch takes over to keep it going. If your inclined look at the fly weights on the motor shaft you see how they actuate the switch.

I thought the centrifugal switch controlled the L1 to the heater.

[Vance R]

You caught me !  Went and looked at the schematic. This one is a evenheat dryer. The push to start switch is in parallel run relay. When push the switch the evenheat board is supposed to energize the run relay and the enerigize the heater relay.  Re -read JWill's post and it looking more like the board. 

@JWill  does the dryer heat when you keep the push to start depressed?

@  MRApplianceMatt   Yes that is correct.  The centrifigal switch has 2 sections.  1 is to complete path to neutral. Other is to complete heater circuit, that way heater can only come on when motor is running.

[JWill]

 

4 hours ago, MD8012 said:

I agree, most likely a motor.  But you do say that it quits as soon as you release the button. Are you saying that as long as you hold the start button in it will run?

As long as the button is held the dryer will run but the heat will not. 

[JWill]

43 minutes ago, Vance R said:

You caught me !  Went and looked at the schematic. This one is a evenheat dryer. The push to start switch is in parallel run relay. When push the switch the evenheat board is supposed to energize the run relay and the enerigize the heater relay.  Re -read JWill's post and it looking more like the board. 

@JWill  does the dryer heat when you keep the push to start depressed?

@  MRApplianceMatt   Yes that is correct.  The centrifigal switch has 2 sections.  1 is to complete path to neutral. Other is to complete heater circuit, that way heater can only come on when motor is running.

No the dryer does not heat.

if it’s the board, is there an easy fix such as replacing a specific diode? 

Also, I connected the wires from the PTS switch and the dryer stays running. Though I did not let it run long enough for the gas to kick on. 

[vee8power]

Try swapping the heater relay and the motor relay and see what happens.

[JWill]

6 minutes ago, vee8power said:

Try swapping the heater relay and the motor relay and see what happens.

I already did that, nothing changed. 

[Vance R]

A i remember there are one or two capacitors that die. Usually the tops bulge. Never have repaired this board, just do swap outs. Core centric does rebuilds on that board.

[vee8power]

Remove the white (neutral) wire and the blue/black (start sense) wire from the even heat board and check the resistance between those two wires. what do you come up with?

[Captain Dunsel]

1. Press and hold the PUSH TO START switch.

   1. Check the voltage at the PTS switch. If 120VAC is

      not present at both terminals, replace PTS switch.

   2. CheckthevoltageattheMotorRelay:Bothsidesof the Motor Relay contacts (large terminals) should be 120VAC with reference to Neutral.

      If 120VAC is not present at one of the Motor Relay contacts, then check for 48VDC from P2-7 to P3- 2. If 48VDC is correctly shown, replace the Motor Relay. If not 48VDC, then replace the Even Heat control.