Update on Samsung dryer
I'm still stumped by this.
I have now replaced the control board, all fuses, the thermostat and the thermistor. I have also replaced all the external ductwork and have reduced the run to about 8 feet with one 90 degree bend. The 90 degree is a smooth sheetmetal elbow.
Additionally, I have thoroughly cleaned the lint filter, the lint filter housing, the duct from the housing down to the blower and the blower itself. The only thing that I haven't cleaned is the bit of ducting that goes from the heater to the back of the drum. I'm not sure how to get to this without removing everything inside the dryer.
Does anyone have any ideas? I'm really close to cutting my losses and buying a new dryer which is not what I'd like to do!