The Micromint RTC‑AD12E is a compact analog expansion board featuring a 12‑bit plus sign A/D converter capable of >20 kS/s over a ±5 V input range, with built‑in overvoltage protection and input scaling. Common failure points for this class of high‑speed ADC boards include degraded input protection diodes, cracked or broken trace connections from the ADC pins to the PCB, and power supply decoupling capacitor failures that cause noise or conversion errors. First‑check diagnostics: verify the 5 V/–5 V rail voltages at the board’s power connectors; inspect for visible damage on the input lines and decoupling capacitors; run a quick test of the ADC output against a known reference signal to confirm linearity and check for erratic spikes.[oss-gpt-20b]