If the standby LED is off, the issue is in the Input or Standby stage.
Why is the so vital? Unlike linear power supplies, SMPS boards operate at high frequencies with feedback loops. Without a schematic, you are essentially working in the dark. 17ips72p schematic
Plug in charger, light comes on for 1 second, then turns off. Charger voltage drops to 0V. Schematic Solution: Look at the power tree. Find all components labeled +3VLP. Use thermal camera (or alcohol swab test) on components like the EC, audio codec, or Touchpad IC. The schematic shows that the +3VLP rail powers the System Management Bus (SMBus) . A short on this rail prevents the charger IC from talking to the battery. If the standby LED is off, the issue
In the world of laptop motherboard repair, a schematic diagram is the equivalent of a treasure map. For one specific and popular model—the —the magic search term you need to know is "17ips72p schematic." Without a schematic, you are essentially working in the dark
Output pins for the LED strips, where you will find the V_LED+ and LED1_S/LED2_S return lines. Common Faults and Repair Tips