While working with another tech on a FS-9530DN with a 6050 error that would not clear this is what we found. The tech had already replaced the Engine board twice, the low voltage power supply twice and the fuser three times. After still getting the same error we replaced the EEPROM on the engine board and the error cleared. The EEPROM could not be reflased because it was defective all together. Since you have to move the EEPROM when you change the engine board the tech was always moving the problem back into the machine.