Product review (1 stars): DMT400RHS history of troubles and solution/fix to the squeal/whine/high pitched noise
Over the years my DMT400RHS became much, much louder and developed two kinds of squeal/while/high-pitched noises/sounds: one during washing cycle, another during drying. Internet is full of complains about both, there are different recommendations on what to do, but here is the fix/solution to both. Noise during drying cycle comes from the drying motor that is in the door, the motor has two cage type fans that circulate cold and hot air loops for the condensation drying. Each fan has with parallel fins attached to a round disk on one side, I had to disassemble the door (easy) and remove the motor from the plastic ducts (not so easy). I could immediately see that hot air look fan fins got melted and shaped into more of an open cone instead of a cylinder and I could see edges ground by the housing they started to catch. To fix it I created a notch about 10mm from the end of each fin on the outward edges by rotating the fan and touching them with a tip of soldering gun. Then I put a thin copper wire into the notch and around the fins to pull them back into the cylindrical shape and re-assembled the motor/ducts/door. Note that motor and ducts have some sealant in the connections, I used some silicone caulk to seal it back. This fix gets rid of the noise completely in my case. Being an engineer I can tell it's a design flaw, saved 5 cents worth of plastic and didn't check for temperature resistance, or it was done on purpose to make people buy a new one in 2 years.
The washing cycle noise came in from the pump pulley being too low on the shaft. I unscrewed all the screws and removed all the covers that are layered above the motor pulley (easy) for cleaning and also unscrewed and removed the pulley. I noticed, that there is some circular abrasion under it. Being familiar with design approaches and/or manufacturing defects, immediately realized this is the issue, to fix it put a 1mm thick stainless steel washer between the disposer knife and the pulley. I also added a smaller washer of the same thickness on top of the shaft in order not to create a strain on the plastic pulley (manufactured this washer myself with the use of a drill and a rotary tool, since the shaft has splines) in order not to create a stress on the top of the pulley from the pressure of the screw, but it may be a bit of an overkill, I guess a big flat washer under the screw could take care of it. This took care of the second noise in my case.
These two problems were on top of the very first problem that I had with this dishwasher right after warranty period expired. It developed a leak through the corners of the door because of splitting of the plastic halves of the lower spray arm. Samsung even had a warning about it on their website. When this happens it starts spraying water really hard horizontally and it's forced through the seal on the sides. Had to order a replacement arm which has been holding ok since then.
The verdict - crappily built piece of appliance, designed to make owners waste their money and suffer for an extended period of time.
Samsung really frustrated me with the quality of their appliances, out of a set of 4 (fridge, hybrid induction range, OTR microwave and dishwasher) EVERY single one had issues/repairs over 4 years I had it. Induction range inverter module had to be replaced 4 times during the first year and was finally fixed by "revision B" of it. Microwave hi power circuit relay fried and stuck in an ON position, causing it to turn on by itself when you close the door. I'm glad we were home when it happened, fixed it with replacing a $10 relay. Fridge stopped cooling at some point and stuff would go bad in no time, until we noticed. They have some kind of magnetic type switches on the top of the doors that are affected by any piece of metal coming into proximity and when that happens it thinks that the door is open, turn inside light on and stops the fan that runs air through the evaporator coil. Why do they have to stop the fan when the door is open, I have no idea. To save me 3 cents of energy a year? To not suck me in? In any case, by the time I found out what was happening, I spent hours on troubleshooting and had the cover/fan partially disassembled.