Answer: Worn PWM drivers or MOSFETs cause erratic voltage. UpFix upgrades those components and calibrates steady speed under load, usually repairs are done within 1-3 days.
Quick take: Sudden bursts or dips in belt speed point to a pulse‑width‑modulation (PWM) control issue on the board.
Symptoms
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Belt briefly speeds up then settles
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Unstable pace under heavier runners
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No error codes on the console
Technical insight
Speed is governed by PWM signals feeding the MOSFET gate. Heat‑fatigued driver ICs or cracked solder joints make that gate voltage wander, which your feet translate as jerky motion.
What to test
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Speed sensor: Verify proper alignment and clean any dust from the magnet or optical disc.
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PWM scope: If you own an oscilloscope, probe the gate at 5 mph, pulse width should stay flat. Variability means bad drivers.
UpFix solution
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Replace driver ICs with automotive‑grade equivalents
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Reflow high‑current solder joints under a thermal camera
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Road‑test on a variable‑load jig for 20 minutes
Stay smooth
Keep the motor and deck clean, use silicone lube, and vacuum under the hood monthly.
Ship your board today 1-3 day turnaround, save up to 80 %, dial 888‑979‑9343.