Won't start

Different sounds point to different components: 'Thumping' = check loose tumbler baffle, rear roller(s) worn/misaligned, out-of-round tumbler or high weld seam. 'Ticking' = check loose wire harness or object in blower wheel area. 'Scraping' = check front/rear bulkhead felt seal out of position or worn tumbler front bearings. 'Roaring' = check blower wheel rubbing on housing or bad motor bearings. 'Popping/squealing' = check sticky or frayed belt. 'Whistling from door' = check door seal assembly condition and door lever.

If screws for fixing the power cord are dropped into the dryer during service, they can be recovered through the duct exhaust hole. Remove the Duct Exhaust (1 screw from Back-Cover, 1 screw from Duct-Exhaust) and retrieve the dropped screw through the hole. This avoids a full disassembly just to retrieve a dropped fastener.

Gas model ignition problems produce three distinct symptoms requiring different diagnosis: (1) Igniter does not glow = check flame sensor, igniter, booster coil, wiring, motor switch, control power. (2) Igniter glows but no gas ignition = check secondary coil, holding coil, wire harness, stuck flame sensor. (3) Gas ignites but flame goes out = check radiant sensor contacts, weak gas valve coil, weak Hi-Limit, poor venting, bad drum seals. Identifying which symptom is present dramatically narrows the diagnosis.

Before touching or replacing any PCB (Main or Sub), you must discharge static electricity from your body by contacting the power plug first. Static electricity from the resin parts of the dryer or the human body can damage electronic components. This is explicitly required before any PCB work.