Lexmark C782 Service Manual - Page 116

5061 AC and DC power service check Before proceeding with this service check remove or disconnect any options that may be installed. Turn the machine on. If it operates correctly, reattach one option at a time until the failing option is located. Note: Set the voltage range switch to the proper power setting for the geographic area you are in. Note: Before proceeding with this service check, turn the printer on, and check to see if the Power on LED on the system board is turned on. Step 1 Actions and questions Is the LED turned on? Yes Go to "AC power service check" on page 2-74. No Go to "DC power service check" on page 2-75. AC power service check The printer appears to be inoperative when turned on with the Power on/Status LED off, the LCD display is blank, the fuser lamps do not come on, and no motors turn. Step 1 Actions and questions Main AC power-Make sure the printer is receiving main AC power. Is the printer receiving AC power? 2 AC power check (wall outlet)-Check the AC line voltage at the AC outlet. Is the AC line voltage correct? 3 AC power cord Is the power cord in good condition and correctly installed? 4 AC power check (AC line cord)-Check the AC line voltage at the end of the AC line cord. Is the AC line voltage correct? 5 Low voltage power supply-Turn the power off, and disconnect the LVPS at J18 on the system board. Measure the voltages on J18-3 and J18-4. The voltage should measure approximately +5 V dc. Is there approximately +5 V dc on any of these connector pins? Yes Go to step 2 Go to step 3 Go to step 4 Go to step 5 Replace the system board. See "System board removal" on page 4-89. No Inform the customer that AC power to the printer is incorrect. Inform the customer that the AC line voltage is incorrect. If the cord is in poor condition, replace the cord. Replace the line cord. Replace the LVPS assembly. See "LVPS assembly removal" on page 4-53. 2-74 Service Manual