NED5500TQ0 Dryer won't start (Possibly the start button?)

OUberLord

Premium Member
Joined
Mar 14, 2017
Messages
4
Location
Midwest, USA
Model Number
NED5500TQ0
Brand
Amana
Age
6-10 years
I've found my dryer to be inoperable today, and have started the troubleshooting process. What was found was that while the light in the barrel comes on, and the door switch seems to operate properly, the dryer will not start when the start button is pressed and a valid setting is on the dial.

Here's what I've done so far:

Thermal switch: Tested for continuity (got good tone from my multimeter, didn't check resistance). Seems to test ok.

Start switch: Tested for continuity from one of the side terminals to the "middle" terminal. Exact part is this: WP3398094

Here's where I get slightly out of my depth. It appears that I can get continuity when I am testing the normally open circuit and the button is pressed. Additionally, I do not when the button is released.

However, I do not get any continuity across the normally closed circuit, regardless of the state of the button.

Does this indicate a bad switch? In theory the button press action still completes a circuit, but I don't know if the fact that I'm not getting continuity across the button released state means anything or not.

Barring that, I'm wondering what else might be at fault. I tried different positions on the dial, but regardless when I push the start button nothing happens (noise, motion, or otherwise).
 
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rickgburton

Appliance Tech - Moderator
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Messages
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Location
Murray, Utah 84107, United States
That's not the model number. Be sure to read it from the tag on the machine. Click here: http://www.repairclinic.com/ then follow the link “Help me find my model number”.
 

rickgburton

Appliance Tech - Moderator
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Messages
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OK, first, measure the voltage at the power cord connection across L1 (black wires) and L2 (red wires). If your meter indicates 220 VAC unplug the machine and remove the back panel. Check the thermal fuse on the blower housing for continuity. Always remove one wire from the component you're checking for continuity. If the thermal fuse checks good check the thermal cutoff on the top of the element housing for continuity.

If the TCO checks good check the PTS switch. The PTS switch is actually a relay. Contact points are R1 and R2 and are open when the button is out and closed with the button in. A magnetic field is created between R1 and CT1 and holds the contacts closed when the button is released. The switch diagram is on the side of the switch.
PTS Relay.jpg

Thermal Fuse WP3392519
Thermal-Fuse-WP3392519-01993779.jpg

Start Switch WP3398094
Start-Switch-WP3398094-01708909.jpg
 

OUberLord

Premium Member
Joined
Mar 14, 2017
Messages
4
Location
Midwest, USA
I have not checked the voltage across L1 / L2 yet, but I did see that the unit was at least getting some power to it as the light inside the drum illuminated when the door was opened. I'll still check that later on, if only to check off that box.

I wasn't previously aware of the thermal cutoff, but both the thermal cutoff and the thermal fuse both appear to have proper conductivity when unplugged and tested.

The PTS switch is where I'm a bit unsure of. Should I have conductivity between R1 and CT1 when the button is released? If so, this relay may be at fault, because I do not get conductivity across any pair of contacts when the button is in a released state. I do however get conductivity across R1 and R2 when the button is pressed.
 
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rickgburton

Appliance Tech - Moderator
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I marked everything on the switch in the diagram I made for you in my last post. Can't you see it? I think certain mobile devices don't show the images.
 

OUberLord

Premium Member
Joined
Mar 14, 2017
Messages
4
Location
Midwest, USA
Ah, I do see that now. When I measure R1 to CT1 I get about 1700 Ohms, and conductivity behavior matches the diagram exactly. With that, it seems that the thermal fuse, thermal cutoff, and PTS switch/relay can be ruled out as the culprits.

I appreciate your help. What components remain that could prevent the unit from starting at all? Is there a straightforward way to verify the timer dial is working properly?
 

rickgburton

Appliance Tech - Moderator
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Messages
33,517
Location
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With that, it seems that the thermal fuse, thermal cutoff, and PTS switch/relay can be ruled out as the culprits.
Think about that for a minute. If the PTS switch is good, just the opposite, it leaves one of the others as the likely culprit. Most likely the thermal fuse. The link is also in that post.
 
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