The ISE Electronics GU256X64‑352 is a 42×8 graphic vacuum fluorescent display module designed for industrial control panels, powered at 5 V and driven via a parallel interface. Common failure modes include burnt or degraded phosphor segments due to overvoltage or power surges, failure of the internal drive IC (often an IBI M2VO controller), and connector corrosion causing intermittent signal loss. First‑check diagnostics: verify that the module receives clean 5 V ±10 % from the supply; inspect the parallel data lines for continuity and correct voltage levels; visually examine the display for burn marks or discoloration, and review any error codes from the host controller that may indicate a driver fault.[oss-gpt-20b]