A loud clicking sound

To reset the drum light on just about any Sharp AL series copier press the following key's in sequence and as quickly as possible (with 4 seconds for the first 4 keys)
Press "C" then the far left key (exposure mode) then the "C" key then the far left again.
So in other words C, far left, C, far left
Some model's use 2 other initial codes, so you may need to use one of these 2 alternate codes to get your display to go blank. The rest of the procedure is the same.
Alternate codes are: #, * , C, * or pound,star,C,star and also
#, Interupt, C, Interupt
If done correctly the display should go blank.
Then key in 24 as if you were going to make 24 copies.
Now press the "print" button
Now key in 7 as if you were making 7 copies
Now press the print button again.
You should now be getting flashing zero's on the display.
Turn the machine off then on again and your drum light should be gone!
You can usually reset this counter at least once to get twice the life out of your drum unit.
This works in the following models:
Sharp AL1000, Sharp AL1010, Sharp AL1020, Sharp AL1041, Sharp AL1200, Sharp AL1215, Sharp AL1220, Sharp AL1250, Sharp AL1251, Sharp AL1340, Sharp AL1451, Sharp AL1520, Sharp AL1521, Sharp AL1530CS, Sharp AL1540CS, Sharp AL1551, Sharp AL1551CS, Sharp AL1631, Sharp AL1641CS, Sharp AL1651, Sharp AL1651CS, Sharp AL1655CS, Sharp AL1661, Sharp AL1661CS