The problem of print head does not flash spray is mainly due to the problem of optical fiber transmission line. As we all know, optical fiber is very easy to be damaged, it is easy to break, can not be bent. So,when we must use ,replace and plug very carefully . If the flatbed printer print head can not flash spray, we must firstly consider to plug fiber, check whether the signal is normal, can flash spray or not? If it is OK, continue to use; if not, you can only replace a new fiber optic transmission line. Under normal circumstances, after the replacement flashing spray will be OK, if not yet, then you need to call the manufacturers to ask technical support.