What is the solution for error 4718 abnormal light. Scanner is a Fujitsu f1-4750C

SOURCE: what is error code "4718

For the sensor of the scanner to correctly detect the image on the paper to be scanned the light that falls on the paper must be as close as possible to pure white and very bright. That light is generated by 3 separated CCFL neon tubes - red, green and blue - that are powered by a special board - the ballast .
That error signals the failure of one of the CCFL tubes - all of them, and their ballast board, as an complete unit, will have to be replaced. That is an extremely complicated repair, only a dealer's repair shop has the necessary replacement part and the skills to do the job - you will have to contact them and arrange for a visit. Be prepared, it will be expensive.