I've had this laptop for 8-9 years, and about a week back, it started malfunctioning. When I press the power button, the power LED comes on for about 5secs and turns off. The fan also doesn't spin at all during this time. But, if I press the power button, and then manually spin the fan, the laptop boots up and the fan starts spinning on its own. Even if I do this, and the laptop boots up, it turns off (hard shutdown) after some time between 10secs and 1hour randomly. I've tried checking the fan voltage and it's at zero volts when I press the power button without spinning it, but when I spin the fan, the voltage goes to 5V. Please bear with me as I'm a beginner in this field, although I have experience with soldering, and using a multimeter.
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Someone please help me with this -
Be sure that your power adapter is the original and with a proper power rating. This is important. Another common fault is that the adapter connector on the logic board does not properly mate with the PSID = power supply ID pin which is the center needle like pin on the power adapter connector. In the absence of this pin, the logic board will assume the power adapter is under rated and will not boot.
Next...
Based on the age of the unit, suspecting the fault may be linked to an aging / shorted capacitor. When a typical capacitor dies, it acts like a shorted component which will draw more than normal current for that power rail. There are current sense circuits on each power rail and this event will force the immediate power down of the rail and logic board. It is also possible that a transient event has caused more severe damage such as the CPU.
To start this review, remove all power. Disconnect the battery. Meter in resistance mode. Is your meter a manual resistance scale type or auto-select for the resistance? Place one probe onto any inductor on the board. Other meter probe to ground. Measure the resistance. If the meter reports, 'OL' = over limit, then switch to a higher resistance scale till you have a measurement. We are checking for shorted parts by checking each and every inductor. Each inductor will be with 2 leads and usually grey in color. Varying with where you are located, there are bound to be logic board repair techs that can also service this unit.
Post any low resistance inductors for a review.Comment
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First off, thanks for helping me out.
The power adapter is the original one that I've gotten with the laptop, and this exact problem occurs both with using the power adapter, and using just the battery. I too have suspected a damaged capacitor to be the cause, but physical inspection yields no results. Everything looks like normal.
I have a manual resistance scale type multimeter. These are the values of all of the inductors:
PL16 - 1.2 Megaohm (Kept increasing)
PL804 - 20 ohm
PL803 - 93 ohm
PLW1 - 18.75 Kiloohm (Also kept increasing but eventually started decreasing)
PL602 - 230 ohm
PLM2 - 430 ohm
PLV2 - 26.5 ohm
PLV3 - 26.5 ohm
I don't think there are any shorts in this case. What do you think?Comment
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mon2 Sorry for bugging you, but I don't have much time to finish fixing the laptop. Could you please help me out here?Comment
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No info is shared w.r.t measurements and steps taken other then describing the symptoms. This is not enough to give any valuable suggestions.
First thing to do is check whether 3V/5V ALW rail is transferred to 3VS/5VS after power switch press. There should be a dc -dc converter for this . very likely 14 pins with 7 pins each side.
When it boots up fine and abruptly shuts down,do you get a thermal warning on next boot?Comment
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showing power does nothing randomly turns on with 2 flashes: https://youtu.be/ZHME8GthErc
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