In certain aspects, a controller for controlling a memory device includes a memory and a processor. The memory is configured to store instructions. The processor is coupled to the memory and configured to execute the instructions to perform a process including receiving data describing a read failure of a set of error handling mechanisms, where the read failure indicates that the set of error handling mechanisms handles a read error on a block of the memory device and fails to read data stored in the block; and responsive to the read failure of the set of error handling mechanisms, performing a memory test on the block to determine whether the block malfunctions.