Safe Place 97770 Card Reader is an industrial access‑control reader that interfaces with a control panel via a serial or parallel bus and supplies power to the card reader module. Common failure modes for this model include burned‑out power supply ICs, degraded magnetic read heads, and corrosion of the contact pads on the reader board; these symptoms often manifest as intermittent reads or complete loss of communication. First‑check diagnostics: verify that the unit receives its rated input voltage (typically 12 V DC) and confirm no tripped fuses; inspect the card reader PCB for visible damage such as burnt components, cracked traces, or loose connectors; then test the serial/parallel interface with a loopback or scope to ensure proper signal integrity.[oss-gpt-20b]