Acer Aspire V3-772g Not turning on when plugged in repair: Difference between revisions

Acer Aspire V3-772g Not turning on when plugged in repair
Device	Acer Aspire V3-772g
Affects part(s)	Motherboard
Needs equipment	multimeter, soldering iron, soldering station
Difficulty	◉◉◉◌ Hard
Type	Soldering

Latest revision as of 17:33, 25 November 2023

This article is a stub. You can help Repair Wiki grow by expanding it

Problem description

#incomplete

A Picture of the first 2 Mosfets from the acer aspire v3-772g motherboard (Figure 1)

Symptoms

Not turning on when plugged in to the charger

Solution

Diagnostic Steps

Check voltage on the input MOSFETs

check if there is 19 volt after the 2nd Mosfet, see figure 1 for where to place red probe of your Multimeter. If there is 19 volt then your first 2 mosfets have not failed and the fault lies in deeper in the motherboard, if you don't see 19 v then proceed to the repair steps below.

Measure for a short circuit after the 2nd input MOSFET

How to find short circuits?

Measure the resistance to ground of the output of the 2nd input mosfet. If you read below 100 Ohms then you have a short somewhere, proceed to repair steps below.

Repair Steps

Low or no voltage at the second input MOSFET

If you measure voltage fluctuations, such as 17v, 20v, 15v, 19v, and so forth, with variations exceeding 1 volt, your power brick may be the likely culprit. In that case, examine the power brick's output port using a multimeter, where the middle pin should register 19v, and the outer metal part should indicate ground.
If there is no voltage, one of the Mosfets might be blocking it. Check the input of the first Mosfet, as highlighted in yellow in the provided image. If there's no voltage at the first Mosfet's input, ensure your multimeter is correctly configured by testing it on a known working battery.
If the multimeter is functioning properly, inspect the power jack using the continuity setting. The middle pin, connected to the input of the first Mosfet (yellow), should beep, and the ground should also beep when checked against the copper circle. If there's no beep, inspect the jack or cable for any signs of damage, such as rips or breaks. Similarly, check the ground by comparing the outer shell of the power jack to the copper circle; a beep indicates a secure connection, while no beep suggests a break in the connection. It's crucial to note that the 19v and ground must be separate, and any beep lasting longer than 1 second between ground and 19v should not occur.

Short circuit on the input voltage

Use a variable power supply, set at 19 volts with a 1-amp limit. inject voltage at the location indicated by the red line (output of the 2nd Mosfet, figure 1). The power supply voltage will decrease by 3v, 5v, or 10v based on the resistivity of the short circuit. Lower resistance results in less voltage drop, while higher resistance leads to a greater voltage drop due to the current being capped at 1 amp. If the power supply displays 5v at 1 amp, it indicates that the component drawing power is consuming 5 watts, generating considerable heat depending on its size. Use your finger to identify the overheating components. If you can't locate the issue, increase the amperage limit to 2 amps, intensifying the heat output. Once you identify the fault, remove the component, check if the short is resolved, and replace the component. If the short persists after replacement, continue searching. The component generating the most heat is likely the one causing the short circuit.

@@ Line 1: / Line 1: @@
+{{Repair Guide
+|Device=Acer Aspire V3-772g
+|Affects parts=Motherboard
+|Needs equipment=multimeter, soldering iron, soldering station
+|Type=Soldering
+|Difficulty=3. Hard}}
 {{stub}}
-{{Repair Guide
-|Device=
-|Affects parts=
-|Needs equipment=
-|Type=
-|Difficulty=
-}}
 ==Problem description==
 <nowiki>#</nowiki>incomplete
@@ Line 16: / Line 16: @@
 ==Solution==
-Possible Solution(s): check if there is 19 volt after the 2nd Mosfet, see picture for where to place red probe of your Multimeter
-If there is 19 volt then your first 2 mosfets have not failed and the fault lies in deeper in the motherboard, if you don't see 19 v then:
-*
 ===Diagnostic Steps===
 ==== Check voltage on the input MOSFETs ====
 check if there is 19 volt after the 2nd Mosfet, see figure 1 for where to place red probe of your Multimeter. If there is 19 volt then your first 2 mosfets have not failed and the fault lies in deeper in the motherboard, if you don't see 19 v then proceed to the repair steps below.
+==== Measure for a short circuit after the 2nd input MOSFET ====
+[[Short Circuits - Repair Basics|How to find short circuits?]]
+Measure the resistance to ground of the output of the 2nd input mosfet. If you read below 100 Ohms then you have a short somewhere, proceed to repair steps below.
 ===Repair Steps===
@@ Line 31: / Line 30: @@
 ==== Low or no voltage at the second input MOSFET ====
-* If you see fluctuating voltage like 17v then 20 then 15 then 19 and so on, if the voltage is fluctuating for more than 1 volt, then your power brick may be the culprit, if yes then check the power bricks output port with your multimeter, middle pin is 19v and the outer metal part is ground.
+* If you measure voltage fluctuations, such as 17v, 20v, 15v, 19v, and so forth, with variations exceeding 1 volt, your power brick may be the likely culprit. In that case, examine the power brick's output port using a multimeter, where the middle pin should register 19v, and the outer metal part should indicate ground.
+* If there is no voltage, one of the Mosfets might be blocking it. Check the input of the first Mosfet, as highlighted in yellow in the provided image. If there's no voltage at the first Mosfet's input, ensure your multimeter is correctly configured by testing it on a known working battery.
+* If the multimeter is functioning properly, inspect the power jack using the continuity setting. The middle pin, connected to the input of the first Mosfet (yellow), should beep, and the ground should also beep when checked against the copper circle. If there's no beep, inspect the jack or cable for any signs of damage, such as rips or breaks. Similarly, check the ground by comparing the outer shell of the power jack to the copper circle; a beep indicates a secure connection, while no beep suggests a break in the connection. It's crucial to note that the 19v and ground must be separate, and any beep lasting longer than 1 second between ground and 19v should not occur.
-* if you see no voltage then either one of the mosfets may be blocking it, so check the input of the first mosfet, its marked yellow in the picture.
+==== Short circuit on the input voltage ====
-* if you have no voltage at the first mosfets input, then check if your multimeter is set up correctly by measuring a battery, if the multimeter is a known working one then check the power jack with your multimeter set to continuity, the middle pin is 19v so it is connected to the input of the first mosfet (yellow), and the ground is connected to the copper circle, if you dont hear a beep when connecting middle pin to input of the first mosfet, then check jack or cable if its ripped or broken somewhere, the same thing needs to be done to ground, outer shell of the power jack is ground, so check that with the copper circle if you hear a beep that means that its good, if not then the connection is broken. Important note 19v and ground must be seperate, you should never hear a beep longer than 1 second between ground and 19v.
+Use a variable power supply, set at 19 volts with a 1-amp limit. inject voltage at the location indicated by the red line (output of the 2nd Mosfet, figure 1). The power supply voltage will decrease by 3v, 5v, or 10v based on the resistivity of the short circuit. Lower resistance results in less voltage drop, while higher resistance leads to a greater voltage drop due to the current being capped at 1 amp. If the power supply displays 5v at 1 amp, it indicates that the component drawing power is consuming 5 watts, generating considerable heat depending on its size. Use your finger to identify the overheating components. If you can't locate the issue, increase the amperage limit to 2 amps, intensifying the heat output. Once you identify the fault, remove the component, check if the short is resolved, and replace the component. If the short persists after replacement, continue searching. The component generating the most heat is likely the one causing the short circuit.
-* After checking the top stuff and you still don't see 19 v, even though your power brick has 19 v when you check it separately, then you have a short to ground after the 2nd mosfet which turns on the security system in your power brick cutting your voltage until you unplug and plug it back in from your wall socket. At this point the problem can be anywhere.