: Usually the last rail to appear; if this is missing but others are present, you likely have an SOC (System on Chip) or CPU power management issue. Troubleshooting Tips No Display? A common failure point on this revision is the or a lack of Not Charging? Focus on the
, such as a dead board or no display, so I can provide more targeted test points? la-e791p rev 2.0 schematic
: "Always-on" rails that must be present even when the laptop is off but plugged in. : Usually the last rail to appear; if
LA-E791P Rev 2.0 motherboard (commonly used in HP 15-bs series laptops), a highly useful piece of information for troubleshooting power issues is the SMBUS Address Table Primary Power Rail sequence Critical SMBUS & Power Address Table Focus on the , such as a dead
If you are troubleshooting a "No Power" or "No Display" condition, checking these specific SMBUS addresses can help identify which component (Battery, RAM, or PCH) is failing to communicate: SMBUS Port 7-bit Address 8-bit Write 8-bit Read Battery (BAT) DIMM1 (RAM) Charger (CHGR) Thermal Sensor Common Power Rails to Probe
How to diagnose No +VCC_CORE - LA- E791P Rev 2.0 - No display 7 Aug 2022 —