Samsung Dryer, dve45n5300v/a3 (all electric), no power to front panel

[ghadlock]

Hello everyone-

Short version:
I have a Samsung electric dryer, dve45n5300v/a3, that has no DC power to the front display board.  I've checked all circuits and all of the safety elements (thermal cutoff fuse, thermistors, door open switch, broken belt switch) are in working order and completing their respective circuits.  I have 120V from each power leg to neutral, and 240V between the legs.  On main control board, I have 120V appearing on both the heat and motor relays, relative to pin 1 (brown / neutral) of the power plug, but no DC voltage out to the sub display / front panel, which should be 12V DC between pin 5 (white) and pin 6 (red) and 5V DC between pin 5 (white) and pin 4 (pink).  I've tried 3 main control boards and 2 sub display boards with same issue.  Only things NOT tested are the steam valves (irrelevant) and front touch panel that plugs into the front sub display; almost stumped but suspecting a possible motor issue.  Here are the questions:

- What should the AC voltage read on the main control board 3 pin power plug (brown/blue/black) between pin 1 (brown/neutral) and pin 3 (black wire / motor switch check circuit) as I'm getting 2.5v AC there which seems old. 
- Would a bad motor potentially cause the entire dryer to seem "dead" - i.e. no power to front panel?
- Motor ohms out as follows:  Pins 3 to 4, 1.9 ohms (vs. 2.88 ohm target), Pins 4 to 5 1.9 ohms (vs 3.5 ohms target).  Centrifugal switch looks good inside and out with clean contacts and working switch.

Longer version of the story:

Dryer initially has a "stuck" relay to the motor, so it would tumble without stopping unless door was opened but dryer otherwise worked fine.  Ordered, received and installed a new main control board (noticing bent metal frame and finger prints all over the clear epoxy protecting the PCB) and dryer was "dead" upon reassembly.  Removed control board and as I was putting it back in the (damaged) Samsung box that it came in, noticed an RMA form where someone had already returned this board as being bad via a different distributor than I used!  So, tested the original board (one with stuck relay), confirmed short across motor relay, tapped relay with handle of screwdriver, and it opened!  Reinstalled original circuit board - dryer still dead.  Contacted distributor, they overnighted another main control board and I purchased a sub display also, just in case.  Installed new control board and new sub display at same time - same symptoms - dead.  Testing concluded no DC power out of connector from main display board to sub display, every single wire in wiring harness tests good, only suspect measurement is the 2.5VAC on pin 3 of the power connector to main control board which is a return from the centrifugal switch on the motor.  I've attached a wiring diagram and details of the main control board for reference. 

[ghadlock]

Given that the resistance readings were off on the motor, I ordered a new one which should arrive today.  I'll post an update once I have one. 

[ghadlock]

So the new motor arrived, motor only (noting that I could have paid $30 more for motor assembly that came with the blower fan attached and the fan shroud).  Anyhow, tried to install new motor but the blower fan was seized up on old motor, tried and tried to get it off including "soaking" the shaft in WD40 and letting it sit for a couple of hours.  Ordered a puller that may or may not work. As an interim step, I tried laying new motor beside old one and making electrical connection - display panel still dead and new motor ohms out same as old one so think it is NOT a motor or centrifugal switch issue. 

Has anyone before seen a dead front control panel (i.e. no voltage coming from main control board) on a Samsung dryer and if so what was the cause?  Does anyone know what voltage reading should be between the brown (neutral) wire and the black wire on 3 pin power connector on main board when dryer is in standby mode (i.e. powered on, not running)? 

[ghadlock]

Another question, does anyone have a blower fan / pulley puller that works well on the Samsung blower fan that has two holes across from each other?  I've attached a picture from PartsDr showing what the fan looks like if any one can recommend a puller model that works well with it.  Still going to try to replace the motor since everything else seems to check out.  BTW, I actually called and tried to buy a new dryer since I'm so fed up with this one - TWELVE week deliver interval, so back to attempting to repair...

[Thorning]

Where ar you located as my local Speed Queen dealer has some new electric models in stock . He is located at Benson, Illinois and the phone number is 309 394 2616. The dealer guy is Bruce Heineke.

[tcarmen]

Anyhow, tried to install new motor but the blower fan was seized up on old motor, tried and tried to get it off including "soaking" the shaft in WD40 and letting it sit for a couple of hours.

It's a reverse thread.

You need a wrench on the pulley to prevent the shaft from turning and a socket on the wheel, and the wheel should unscrew clockwise. It's metric.

[ghadlock]

I was able to get the nut off pretty easily - breaker bar and deep socket on the belt pulley, impact driver running in "tighten" / clockwise on the front fan blower matching the "loosen -->" printed on the wheel.  That was, unfortunately, before my struggle to remove the fan which is definitely seized on the shaft.  That said, I tested every pin to every pin on both new and old motor and they are identical, I've concluded that the issue is not the motor so I've put it all back together and am now hoping someone offers inside as to what could be wrong between main control board, sub display board, and touch panel (sub board to the display board) that would cause the appearance of dryer being dead, no DC voltage out of main control board.  My guess would be it is the main control board... but something has to be causing them to fail if that's the case.  Second guess would be wiring harness but I've tested everything that I can for continuity at least, and all sensors / thermistors / thermal fuses / switches (door and belt) are good. Sorry for the diversion away from blower mower, but I've accepted the fact that it's stuck there for now and moved on, thankful that it doesn't have to come off today!

[Thorning]

Suggest you consider replacing it with a new unit such as Speed Queen which is more reliable and  easier to work on.