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Light on DC jack turns on, but laptop does not post or spin fan.
Before plugging in any power supply, use a multimeter in resistance mode to check the main coils (3.3V, 5V, RAM, CPU Core). If any coil reads under a few ohms (excluding the CPU core which naturally has very low resistance), you have a shorted component.
: If these are missing, it is critical to measure the resistance to ground on their respective coils. Low resistance on often indicates a fault with the chip rather than a PCH failure. PQB12 Transistor : A key test point is pin 8 of PQB12
These tools provide standard symbols, automatic netlist generation, and the ability to produce high-resolution outputs suitable for printing or sharing. lae801p rev 20 schematic better
If you are dealing with a specific fault on this board, I can help you decode the exact circuit paths. Could you let me know (e.g., completely dead, spinning fan with no display, power cycling)? If you have a multimeter, sharing which voltage rails are missing will help narrow down the issue. Share public link
Troubleshooting these issues without a proper schematic can be almost impossible. A "better" schematic is not just a simple diagram; it's a detailed, revision-specific map that shows:
Identifying small capacitors, especially those prone to failing under the SoC, which cause NO DRAMRST (RAM reset) signals. Light on DC jack turns on, but laptop
Calling a schematic “better” is subjective unless mapped to specific use cases. Here’s when the genuinely outperforms:
family, is frequently used in budget-to-midrange laptops and presents a few specific quirks during repair. Essential Technical Context
Use a multimeter in Diode Mode to check the main power rails. A reading below 0.010 on the 3.3V line usually indicates a dead PCH or EC. Conclusion : If these are missing, it is critical
Older designs used a simple RC ramp on the enable pin. Rev 20 adds a dedicated soft-start capacitor (Css) connected to an internal 5µA current source. The formula is now:
Physical testing of the circuit, followed by iterations based on the results, ensures the schematic's accuracy and functionality.
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