Coombs' test involves taking a blood sample which is checked for the presence of antibodies which may destroy red blood cells.
You can use the HP Print and Scan Doctor to test the status of the printer spooler, print queue, device manager, and device conflicts. 1  On the desktop, double-click the HP Print and Scan Doctor icon to open the tool. 2  Click Start on the Welcome screen. 3  Select your printer, and then click Next.  Click Fix Printing.
Make sure that you are using the correct settings in HP Solution Center: Right-click the Start button () or the lower left corner of the screen, click Search, type HP Solution Center, and then press Enter. Click the printer icon for the printer that you use to scan. Click Scan Document.note: Do not select Scan Picture, even if the item that you want to scan to PDF is a picture. The Scan Picture selection limits the list of file types to picture file types, which excludes the PDF option.ake sure that you are using the correct settings in HP Solution Center: Right-click the Start button () or the lower left corner of the screen, click Search, type HP Solution Center, and then press Enter. Click the printer icon for the printer that you use to scan. Click Scan Document.