BL1700 is a single‑board programmable controller that houses a Zilog Z180 microprocessor core with 32 K battery‑backed SRAM, 128 K flash EPROM, an RTC and watchdog circuitry, plus modular digital/analog I/O (32 digital lines, ten 12‑bit analog inputs, 16 protected inputs, 16 high‑current outputs). Common failure points for this class include power‑supply decoupling issues on the core module, degraded flash or RAM cells due to aging, and watchdog or RTC oscillator faults that trigger resets. First‑check diagnostics: verify the main +12 V/5 V rails and monitor the core’s voltage regulators; inspect all I/O pins for shorts or burnt components; read any error codes from the onboard LED or serial ports to identify reset causes.[oss-gpt-20b]