Disclosed is an apparatus and method for increasing the error correction capabilities of a receiver circuit that receives a data stream of encoded data symbols that are encoded with a linear block code. Analog and digital comparator circuits are used to detect laser clipping or analog to digital converter overloading. Corrupted symbols are detected by comparing in-phase and/or quadrature phase baseband signals with pre-determined threshold limits that indicate that the in-phase and quadrature phase signals have exceeded the normal signal trajectory of an unimpaired signal. Corrupted symbols may also be detected by determining that the laser has been clipped. Corrupted symbols are marked for erasure prior to decoding and error correction. Erasure of corrupted signals increases the error correction capabilities of the decoder circuit.