Hi my copier displays E7 - Sharp AR-5316 Advanced Digital Imager Copier

Check this out :
E7 codes deal with the optical scanner unit and or the laser unit. It could also be the lamp in the scanner unit. The E7 is the main code. There is a sub code associated with it. To view the sub code hold down the start button. Below is a list of specific codes and their meanings:
E7-02: LSU trouble
E7-10: Shading trouble (Black Correction)
E7-11: Shading trouble (White Correction)
E7-12: Shading Trouble
E7-16: Abnormal laser output
If it is a laser (LSU) issue then the LSU may need replacing.
If it is a shading error the first step is to remove the platen glass carefully (with the power off because the inverter board). There is a thin white strip on the bottom side of the platen next to the **** glass. Clean this white strip with a soft cloth and a small amout of isopropyl alcohol.
Dust on the optics can also cause shading reference errors so gently blow off the mirrors with canned air.
Perform the following key procedure to reset error:
"#" key, Interrupt key, "C" key, Interrupt key
"1" key, "4"key
Start key, "CA" key.
See if unit cycles and comes back up. If not turn off and then back on the main power.
If error reappears on site technical service may be required.