help with dell laptop

[luisardo]

hello everyone! I have a dell g3 3579 that has 2 problems, when I connect it does not turn on immediately, only turns on the keyboard light and the fans spin for a few seconds but then turns off (the screen does not turn on), I can repeat it several times and does not change the result, for the laptop to turn on, I unplug the charger, press the power button to remove the power from the charger and plug it in and turn it back on, that makes the laptop turn on (not always but it does turn on) once the laptop turns on it works normally, wifi, keyboard, processor etc.. . even I can do a stress test for 30 minutes without problems, the problem is when I turn off the pc and I want to turn it back on, I have the same problem, so put the laptop in sleep to not turn it off, I have basic knowledge in measuring with multimeter, someone knows that I can measure to know that could be the problem in the motherboard? I have already checked the basic things like ram, cmos, battery, ssd, etc. sorry for writing so much and thank you for your attention!

 

[pcrepair]

It sounds like you're dealing with a power-related issue, possibly involving the power circuitry on the motherboard. Here are a few steps you can take to diagnose the problem using your multimeter:

Check the Power Adapter and Port:

Ensure the power adapter is providing the correct voltage. You can measure the voltage at the adapter's output.
Inspect the power port for any physical damage or loose connections.
Test the Battery:

Measure the voltage of the battery to ensure it is within the normal range.
Check if the battery is charging properly when connected to the adapter.
Inspect the Power Button:

Use the multimeter to check if the power button is functioning correctly. It should show continuity when pressed.
Check for Shorts:

With the laptop unplugged, use the multimeter to check for any shorts on the motherboard. Pay attention to the power rails and any suspicious areas.
Inspect the DC Jack:

Ensure the DC jack on the motherboard is not damaged and is securely soldered.
Check the Power Rails:

When the laptop is connected to the power adapter, measure the voltage at different points on the motherboard. Look for any irregularities or missing voltages.
Examine the BIOS:

Sometimes, BIOS settings or updates can cause power issues. Consider resetting the BIOS to default settings or updating it if a newer version is available.
Given the intermittent nature of the issue, it might also be worth considering the following:

Loose Connections: Ensure all internal connectors (battery, RAM, SSD) are firmly connected.
Faulty Components: Sometimes, components like the power IC or other power management chips could be failing intermittently.
Thermal Issues: While you mentioned the laptop passes stress tests, it's still worth checking for any thermal damage or loose heatsinks.
If you are comfortable and have the necessary skills, you can also look for visual signs of damage on the motherboard, such as burnt components or bulging capacitors. If the issue persists, it might be best to consult a professional technician for a more detailed diagnosis.

 

[luisardo]

thanks for your answer! the problem is very strange, because the laptop works perfectly when it turns on (I'm writing this from it) I also thought it was something with the power rail, I'll check to see what the measurements say, I don't think it's a short circuit or anything like that, right? if it was that it wouldn't turn on.