The in use alarm appears to be related to fax reception and printing. There are some options below that you could try:-
If the machine receives a fax under one of the following conditions, it will not be able to print the received fax and will store it in its memory. The In Use/Memory lamp is lit and Received in memory is displayed on the LCD. When the problem is resolved as described, the fax stored in memory is printed automatically.
- Ink has run out: Replace the FINE Cartridge.
- You can set the machine to forcibly print a received fax even if the ink has run out.
However, part or all of the fax may not be printed since the ink has run out.
Also, the contents of the fax will not be stored in memory.
If the ink has already run out, we recommend that OFF be selected for Auto print in FAX user settings to store the received fax in memory and print the fax manually after replacing the FINE Cartridge. After you replace the FINE Cartridge and select ON for Auto print, the fax stored in memory will be printed automatically.
- Paper has run out: Load the paper and press the OK button.
- A different size of paper from that specified by Page size is loaded:
Load the same size of paper as that specified by Page size, then press the OK button.
- Page size is set to other than A4, 8.5"x11"(LTR), or Legal (or 8.5"x14"):
Set Page size to A4, 8.5"x11"(LTR), or Legal (or 8.5"x14").
- Media type is set to other than Plain paper:
Set Media type to Plain paper.
- You pressed the Stop button to cancel printing of a fax:
Press the FAX button
Alternatively turn the printer off, open the devices and printers section of Control Panel, right click on your printer and select "see what's printing" and left click on this. A window will pop up which may or may not contain a list of documents. If it does these must be cancelled (Menu - Printer - Cancel all documents). Once all documents have gone from the list turn the printer on and try to print.
Other than the above suggestions I would need to know more about your OS and exact problem. Hope this helps.