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Forum Index => Dryer Repair => Topic started by: Joeyt56 on March 01, 2017, 09:41:51 PM

Title: Samsung dryer, frustrating
Post by: Joeyt56 on March 01, 2017, 09:41:51 PM
Working on a samsung dryer no heat. Checked everything. I get 110 volts on one leg to the heater but I lose the other 110 volts coming through the relay on the board. If I unplug and by pass the relay the heater works fine. So it has to be the board or the thermistor.  Since the resistance of the thermistor is around 10,000 ohms at room temp its checks out good. Had one on my van so changed it out anyways and no chang. Also checked the harness from the thermistor to the board and its good as well. So i replaced the board with no luck. Again i check everything. Order a new board and again no heat. What the hell is going on? Could the userinterface be causing thks somehow? Model#dv45h7000ew/a2 (https://click.linksynergy.com/fs-bin/click?id=omv7WULuxaw&subid=0&offerid=225193.1&type=10&tmpid=2111&RD_PARM1=http&RD_PARM2=%253A%252F%252Fwww.appliancepartspros&RD_PARM3=.com%252Fparts-for-samsung-dv45h7000ew-a2-0000.html)
Title: Re: Samsung dryer, frustrating
Post by: dentdaddy on March 02, 2017, 06:51:03 AM
I had one of these too. It turned out to be the centrifugal switch in the motor. Attempting to attach a pic. You can bypass the switch by jumping these 2 outer wires on the board. There is a 3 wire molex in the corner of the main PCB, jump the brown and black wire (2 outer wires. If heat works, replace the motor.
Title: Re: Samsung dryer, frustrating
Post by: Joeyt56 on March 02, 2017, 07:49:37 AM
I had one of these too. It turned out to be the centrifugal switch in the motor. Attempting to attach a pic. You can bypass the switch by jumping these 2 outer wires on the board. There is a 3 wire molex in the corner of the main PCB, jump the brown and black wire (2 outer wires. If heat works, replace the motor.

When the motor is running I get 120 through it to the heater. The other 120 I'm losing at the heater relay at the board. If I jump the relay then the heater works normally.
Title: Re: Samsung dryer, frustrating
Post by: Chris042281 on March 02, 2017, 02:48:45 PM
The motor has two switches on it.
Title: Re: Samsung dryer, frustrating
Post by: Joeyt56 on March 02, 2017, 09:31:10 PM
The motor has two switches on it.

Does the motor tell the main control to close the heater relay? Because I have pin pointed the heater not coming up because the heater relay on the main control will not close to allow power through. Again when I jump out the relay the heater and everything else operates normally. Which means the motor is allowing power through which I have tested already. 120 volts comes through the motor to the heater and the remaining 120 volts to power the 240 v heater is supposed to come through the main control board through the heater relay. For some reason the heater relay will not close. What is the second switch your referring to? Does it signal the control board? The centrifugal switch is the only switch I know and is what allows power to the heater and is operating correctly.   
Title: Re: Samsung dryer, frustrating
Post by: schleven on March 04, 2017, 02:35:16 PM
I have seen a few lately that had bad switched in the motor. Here's a pic of the switch. Don't have the whole diagram
Title: Re: Samsung dryer, frustrating
Post by: schleven on March 04, 2017, 02:38:30 PM
I am pretty sure that the heater relay on the board was working on the ones I had to replace the motor on.
Title: Re: Samsung dryer, frustrating
Post by: Joeyt56 on March 04, 2017, 07:58:55 PM
Thanks for the info guys, I might as well add a motor to my order and have multiple part to try. I'll be shocked  if this somehow controls the relay but I'm at my wits end so it's worth a try.  You don't happen to have a complete wiring diagram do you? It would certainly help clear things up.
Title: Re: Samsung dryer, frustrating
Post by: schleven on March 04, 2017, 08:09:56 PM

Thanks for the info guys, I might as well add a motor to my order and have multiple part to try. I'll be shocked  if this somehow controls the relay but I'm at my wits end so it's worth a try.  You don't happen to have a complete wiring diagram do you? It would certainly help clear things up.


I am not sure that this is your model, but it was out there on the web..
Title: Re: Samsung dryer, frustrating
Post by: Joeyt56 on March 04, 2017, 08:58:44 PM
Thanks, looks pretty straight forward, line 2 passes right through the motor switch with 120v. Which I have tested, I'm positive I'm getting power through this switch. Looks like the second switch is the neutral.  Then line one feeds the remaining 120v through the heater relay. If I jump out this relay then power flows and the heater comes on. So I think I'm still coming back to what closes that relay?  Assuming the control boards are not defective, what tells the relay to close is the thermistor, correct? I guess I'll also have another thermistor and control as well along with the ui and motor one way or another this think is getting fixed lol.
Title: Re: Samsung dryer, frustrating
Post by: Joeyt56 on March 04, 2017, 09:04:04 PM
Found the tech manual. What do you think they mean by the membrane switch open? Are the referring to the UI?
Title: Re: Samsung dryer, frustrating
Post by: schleven on March 04, 2017, 09:06:27 PM
Membrane switch open...
Hmmmm
Never seen that.
Strange one for sure.
Title: Re: Samsung dryer, frustrating
Post by: dab147315 on March 05, 2017, 10:02:40 AM
Maybe this would help. https://drive.google.com/file/d/0B-i5KqMA2RZwaUtxQ2RtdVF6a0U/view?usp=sharing
https://drive.google.com/file/d/0B-i5KqMA2RZwaGEwX3h6ajZ5aGM/view?usp=sharing
Title: Re: Samsung dryer, frustrating
Post by: Joeyt56 on March 05, 2017, 11:03:07 AM
Maybe this would help. https://drive.google.com/file/d/0B-i5KqMA2RZwaUtxQ2RtdVF6a0U/view?usp=sharing
https://drive.google.com/file/d/0B-i5KqMA2RZwaGEwX3h6ajZ5aGM/view?usp=sharing

Interesting, so the membrane it's referring to is the centrifugal switch. Well I've got a motor, a main board, thermistor, and a sub Pcb on the way lol. I will certainly update everyone as soon as I'm done.  Gain thanks for all the troubleshooting
Title: Re: Samsung dryer, frustrating
Post by: dufuss on March 09, 2017, 12:03:25 PM
The  push button panel from my understanding is the membrane switch.  Does the dryer have this?(http://)
Title: Re: Samsung dryer, frustrating
Post by: scrapiron on March 09, 2017, 12:57:33 PM
Since I couldn't find any mention of this in the Samsung service manual, what is the motor sensing function of the board and motor switch? It connects terminal 3 of the AC connecter to neutral. No heat? Anybody know?

I had one of these too. It turned out to be the centrifugal switch in the motor. Attempting to attach a pic. You can bypass the switch by jumping these 2 outer wires on the board. There is a 3 wire molex in the corner of the main PCB, jump the brown and black wire (2 outer wires. If heat works, replace the motor.
That's not a good idea as it would short L2 to neutral through the motor switch and door switch. Perhaps he meant jumper the white to black?
Title: Re: Samsung dryer, frustrating
Post by: dentdaddy on March 09, 2017, 02:38:19 PM
In this photo, jumping brown to black bypasses the motor switch. If heater then works you need to replace the motor. This was done per tech support while I was on the phone with them.
Title: Re: Samsung dryer, frustrating
Post by: scrapiron on March 09, 2017, 04:09:36 PM
I stand corrected. I misread the wiring diagram. The brown wire DOES connect to neutral. Good info to know. Sounds like you may have solved Joey's problem.
Title: Re: Samsung dryer, frustrating
Post by: Joeyt56 on March 09, 2017, 06:50:02 PM
And the winner is...... Dryer motor!! Thanks everyone for pointing me in the right direction!  :cheers:   That's is why I keep coming back here for advice when needed usually ends well when I do.

Thanks Dentdaddy for clearing the issue up from a technical stand point, I always like to see WHY something is acting the way it is. Basically the board thought the motor Wasn't running so it wouldnt open the relay to allow the heater to turn on. Pretty simply now that i look at the schematic, just needed to know that the board had that motor sensing function and where it was, schematic leaves that part out lol.And thanks for the tip to test it in the future.
Title: Re: Samsung dryer, frustrating
Post by: dab147315 on March 10, 2017, 03:48:49 PM
So what is happening here, terminals 5 and 6 are not closing and there is no signal back to the board? If so, how are the start windings taken out of the circuit? I am missing something here.
Title: Re: Samsung dryer, frustrating
Post by: Joeyt56 on March 10, 2017, 10:40:09 PM
So what is happening here, terminals 5 and 6 are not closing and there is no signal back to the board? If so, how are the start windings taken out of the circuit? I am missing something here.

Good question, I don't believe they are taken out. In the motor the only reason it switches to the run winding's is to increase efficiency.  The start windings are there for the added starting torque and set the direction of the motor but theres nothing that says the dryer cant operate on the start windings engaged is there?  I could be completely wrong so feel free to correct me if I am lol. My guess is when the switch at 5 and 6 six fails the motor continues to run with the start windings, but the board cant see this because it doesn't receive a signal from the failed switch so it thinks the motor is actually off and wont close the heater relay.
Title: Re: Samsung dryer, frustrating
Post by: dab147315 on March 11, 2017, 12:06:41 PM
Thanks for getting back to me. I just wanted to see if i was on the same page as you.Maybe we can get some more information or opinions on this.I was thinking maybe the contacts of the switch is breaking the circuit of the start windings but not closing 5 &6. Kind of in between.Did find a video of a similair model and at point 51 minutes gives some information on a very similar model.I we post if you want to take alook.
Title: Re: Samsung dryer, frustrating
Post by: dab147315 on March 11, 2017, 12:07:18 PM
Here is that long video.


https://www.youtube.com/watch?v=rqOuKxixMpk&index=11&list=PLMRN1M_nOVCubgFbTkZSmeQxeCazsac-G (https://www.youtube.com/watch?v=rqOuKxixMpk&index=11&list=PLMRN1M_nOVCubgFbTkZSmeQxeCazsac-G)
Title: Re: Samsung dryer, frustrating
Post by: baldwinappliance on March 11, 2017, 09:00:07 PM
Could be wrong but the way I am reading that diagram is that the start windings are on the left. The centrifugal switch has n.o. and n.c. side so the n.c. side that is connected to the start windings is broken but the n.o. side to give feedback to the board is defective and not closing the circuit. So motor can switch over to run windings but still not give feedback to board so board will activate heater relay.

Something to think about in the future when diagnosing as usually I would just jump the relay at the board to test and change the board.
Title: Re: Samsung dryer, frustrating
Post by: dab147315 on March 12, 2017, 09:20:48 AM
More opinions please.
Title: Re: Samsung dryer, frustrating
Post by: Joeyt56 on March 12, 2017, 03:59:43 PM
More opinions please.

Ok so I think Ive gotten to the bottom of this. We are thinking mechanically, We are assuming that a bad switch means that it mechanically is not functioning properly which is ONE way for this to fail. In said case the motor would still run but on both the start and run windings no big deal if it does just wont run efficiently.

The second case scenario which is probably what most guys are encountering is a bad contact! The switch IS closing and IS dropping the start windings but because of carbonization on the contact the circuit is never completed when the switch closes!

Well... I still had the motor so I pulled apart the switch. It was still mechanically functioning but the contact on the neutral was black with carbon build up! The start windings disengaged but the poor contact would not complete the neutral circuit.


Makes more sense now right? I can take pictures of the contact and post later if you would like
Title: Re: Samsung dryer, frustrating
Post by: dab147315 on March 12, 2017, 05:31:14 PM
The second scenario makes more sense to me.
Title: Re: Samsung dryer, frustrating
Post by: afterblast on August 10, 2017, 11:29:19 PM
 Just wanted to update this, I ran into one of these the other day, previous tech had replaced the board and the heater had good circuit path and voltages and they couldn't figure it out so I inherited it.   I remembered this thread and checked the centrifugal switch contacts and sure enough the NO contact on the start winding switch was blown off and missing, when I jumped it out at the board it began heating.  Also found you can put the unit through the relay test mode where it cycles the motor relay on then the heater relay briefly letting you read the amp draw for about 10 seconds to prove that the board could cycle the relay if it wanted to...  none of Samsungs fast tracks or service manual for this unit mentioned this although it shows the circuit in the wiring diagram.  I suspect the idea was that when the centrifugal switch opens the start winding it closes this circuit which lets the board know that the motor is at full speed and then the board turns the heater relay on.   They just forgot to mention it in the tech literature...

Oddly I remembered this thread because I ran into one of these a year or so before finding the thread and I couldn't figure it out, unit was under an extended warranty and got bought out...   don't have that happen a lot so it stuck with me then made sense when I found this thread, and I'd bet good money if I could ever find that dryer I'd find a bad switch..


On a side note anyone know if you can purchase a generic centrifugal switch without the motor attached?   Seen enough switch problems that I'm kinda surprised I can't find just the switch for sale...
Title: Re: Samsung dryer, frustrating
Post by: bl.jamesburton on February 08, 2020, 05:02:43 PM
I am having same issue.

This thread has been very informative. Thanks in advance

Here is scenerio

Control board has been replaced
Element, thermostat, high limit and cut off all show continuity.
Thermister is showing 11k resistance at room temp.
120v from motor to element and 120v from motor to control board means the centrifugal switch is working. (I took it apart and tested it, looks good)

I can run 120v directly from a wall sock to the element to turn it on. Additionally, if I run the vent blockage test, the heater works no problem.

With that being said I can only draw the conclusion that the thermister is defective or the sub PCM is defective. AKA its sending a "no heat" signal as those it is always on Air Fluff mode regardless of the actual setting being chosen.

I have 1 day delivery on the thermister coming tomorrow (im outta clean boxers here gentlemen). Any other ideas?


*edit:  I've realized I didn't test the motor switch correctly. I am getting the 120v to the heater and I did witness the switch working with a multimeter when I took it apart and manually triggered it. However, the switch that controls the power going to the control board I did not properly test. (I tested the black wire into the heater relay which is continuous power)

With this revelation, the motor switch is still up for debate, however, running a vent blockage test turns on the heater. Should this alone rule out a faulty centrifugal switch? Or does the vent blockage test bypass various safeties and relays on the control board? Basically, I need to understand how the vent blockage test works so I can better troubleshoot the issue at hand