Lexmark C510 Service Manual - Page 170

5021-0XX Toner low/empty service check Step Questions / actions Yes No 1 Turn printer off and remove Go to step 2. I/O board shield. See "I/O board removal" on page 4-70 for steps to remove I/O board shield. Is cable properly connected to I/O board connector DCN15? Properly connect cable. 2 Reconnect operator panel. Go to step 3. Turn printer on. Touch negative lead of voltmeter to metal bracket that holds I/O board to obtain ground. Touch positive lead to DCN15 pin 1, 2, 3, or 4 for specific color as dictated by list below: DCN15 pin1-black(K) pin2-yellow(Y) pin3-magenta(M) pin4-cyan(C) Slightly remove toner cartridge in question. Voltmeter should read approximately 4.8 VDC. Continue to slowly slide toner cartridge out of printer while noting voltmeter reading. Voltage should slowly decrease until it reads approximately 0 VDC. Is toner sensor system working properly? Check cable for continuity between I/O board DCN15 and toner sensor system (both sender and receiver). Also check for shorted pins. See "Toner sensor (sender) removal" on page 4-35 and "Toner sensor (receiver) removal" on page 4-64 for steps to expose cable. If cable is okay, replace toner sensor system. 3 Replace I/O board. Problem solved. Replace engine See "I/O board removal" controller board. on page 4-70. Does error See "Engine clear? controller board removal" on page 4-55. 2-92 Service Manual