If your dryer hums but the drum sits completely still, the drive belt is almost certainly snapped. That’s the cause in the large majority of these calls. The idler pulley is the next likely culprit. Both are repairable, and a tech can usually confirm the diagnosis and complete the repair in one visit.
Why the Drum Stops Moving
Broken drive belt. The drive belt is a long rubber loop that wraps around the drum, runs under the idler pulley, and connects to the motor. When it snaps, the motor keeps humming but nothing drives the drum. You might hear a soft thump at startup, or nothing at all. One quick check you can do right now: open the door and spin the drum by hand. If it turns freely with almost no resistance, the belt is gone.
Seized or worn idler pulley. The idler pulley keeps tension on the belt. When the bearing inside wears out, the belt slips or wears through faster. A failing idler pulley usually squeals before it quits entirely.
Drum rollers, glides, or rear bearing. If the drum feels stiff or grinds when you spin it by hand, the issue is probably worn drum rollers, glides (the plastic or felt pads supporting the front of the drum), or a rear bearing. These create enough drag that even a good belt can’t turn the drum. That’s a different repair than just a belt swap.
Motor drive pulley. Less common, but the small pulley on the motor shaft can wear smooth or crack on older machines.
What a Tech Checks
The manual spin test is always first: open the door, spin the drum, note the resistance. Spins freely with no tension at all — broken belt. Grinds or feels stiff — worn rollers, glides, or bearing; the diagnosis goes deeper than just the belt.
With the cabinet open, a snapped belt is usually obvious — it’ll be sitting loose in the bottom of the cabinet in a coil. A worn belt may still be in place but cracked, glazed, or fraying at the edges. The idler pulley gets checked by hand for roughness and wobble. If it’s worn, it comes out with the belt; replacing both at the same time is standard because they wear together and the labor is already done.
One thing worth knowing: a failed door switch can cut power to the drum motor entirely. If the motor is audibly humming, the door switch is working fine and isn’t the problem.
Why You Should Let a Tech Handle It
Getting to the belt means disassembling the cabinet: removing screws and retaining clips, then physically supporting the drum while threading the new belt under the idler pulley and around the motor shaft. The routing has to be exact. A twisted or misrouted belt snaps again quickly or runs loud. Samsung and LG front-loaders involve more disassembly than most platforms and leave less room for error.
More importantly, a tech will inspect the idler pulley, drum rollers, glides, and bearing while the machine is open. If those are worn, you want to know now rather than on a second service call two months later. On a machine that’s 8-10 years old, that full drivetrain check can tell you whether the repair makes financial sense at all. Parts and labor costs vary by brand and model, so get a quote rather than guessing.
Call Us
If your drum isn’t turning, we can usually get out same or next-day across the Tri-Valley and East Bay. Straight diagnosis, honest answer on whether the repair is worth it. Book at adriumservice.com.