Precor 905E 103468852 is the lower‑motor control circuit board used on the 90xx/905e treadmill series to drive the rear motor and manage speed feedback. Common failures include blown or degraded electrolytic capacitors on the power supply section, burnt or tripped relays (often the main motor relay), and cracked solder joints around the microcontroller and driver ICs due to vibration. For a first‑check diagnostic, verify 24 V DC input and check for proper voltage rails at the board’s VCC pins; inspect all relays and fuses for continuity and signs of arcing; then visually examine the board for burn marks or cracked components before proceeding with in‑circuit testing or component replacement.[oss-gpt-20b]