Initial Symptom: LG Dryer Model No. DLEX5101W will start when "start" button is pushed but will shut off after 10 to 15 seconds. This was on medium heat and high heat settings with a load of sheets (large, heavy load) in the dryer. Dryer would not start again immediately but would start again after a couple minutes. Slight burning smell.

Background: Dryer exhaust as 3 ft of flex tube (metal?) then 10" straight run through exterior wall. No lint clogged anywhere in exhaust, blower housing, or dryer at all. No problems prior to initial symptom.

Ran dryer diagnostics: (No Load)
0) Started diagnositcs: No fault codes. No tE1 or tE2.
1) Checking Motor - Motor ran: LCD displayed high moisture, 252 (Dryer is equipped with moisture sensor strips)
2) Checking Motor + Heater 1 (2700W) - Motor & Heater ran. I let it run for 30 minutes and the LCD displayed the temperature which started at 23 deg C and climbed to 77 deg C (could of possibly climbed higher but I went to the next step)
3) Checking Motor + Heater 1 + Heater 2 (5400W) - Motor & Heaters ran. Temperature jumped from 77 deg C to 85 deg C in approx. 30 sec. and tripped Hi-Limit Thermostat on blower housing (Part No. 6931EL3002A) at 85 deg C. This is the temperature that this thermostat is supposed to open (85+/-5). Motor and Heater shut off. I went to next step.
4) Checking Motor, Heater - LCD showed low moisture, 33; motor ran; heater off. I ran this immediately after the motor and heater shut off in the previous step. The diagnostic test table from the dryer lists the checkpoint as "Motor, Heater off". Does this mean both are supposed to be off or just the heater?
5) Control off - Dryer turned off

After running diagnostics:
1. Disassembled dryer - Belt and drum look good. Drum rotates smoothly. No heavy lint anywhere in dryer. No burn spots or questionable looking connections on PCB. Checked 6 pin connectors on PCB for resistance and seems to be operating correctly. No burn spots or poor looking wiring harnesses in dryer. Everything looks brand new.
2. Checked continuity on Thermal Cut Off on heater assembly - Passed
3. Checked continuity on Hi-Limit Thermostat on heater assembly - Passed
4. Checked continuity on Hi-Limit Thermostat on blower assembly - Passed
5. Checked continuity on Heater - Passed on all 3 terminals
6. Checked continuity from Heater to Case - No continuity. Heater is good.
7. Checked resistance on Thermistor - Resistance followed table in Diagnostic Guide from 75 deg F (room temp.) to 125 deg F. I heated a pan on the oven and used a digital thermometer to measure temperature on the pan's surface . I set the metal end of the Thermistor in the pan and measured the resistance as the pan heated up. The Thermistor was much slower at lowering its resistance than the thermometer was at heating up. Concluded Thermistor test when thermometer measured 170 deg F and Thermistor resistance was 3.68 k ohms (approx. 125 deg F per table), according to LG diagnostic table the Thermistor should have a resistance of 2.0 k ohms at 170 deg F. Is Thermistor faulty or because only a portion of the metal part was touching the pan it wasn't reading accurately?
8. Check motor continuity - Tested between terminals from brown wire to white wire while moving centrifugal switch about 1/2" towards blower. Passed.

Thoughts:
It SEEMS as though the motor and heater are both working correctly and that the dryer is not cycling the temperature correctly. The motor will run and the heater will heat until the hi-limit tripped at it's set point. I'm suspecting the Thermistor is faulty and is not communicating the temperature to the PCB correctly EXCEPT when I ran the diagnostics the LCD displayed the 85 deg C temperature at the point when the Hi-Limit Thermostat on the blower tripped, which makes it look like it is functioning correctly. Only other items I think I can suspect at this point are the motor's internal thermal protector and the PCB. Both of these are expensive items to replace so I would like to get it right the first time. Are there any additional tests I can do on the motor or the PCB? Or better yet, does anyone know what the problem is? Any input is much appreciated. Questions?

Thanks!!