Acer Swift SF314-55G, MI4FA MB REV:2.1

[IamPritesh]

I have a short somewhere when I plugin the 19v adapter , the voltage on DICIN connector drops to 2 Volt. I have never worked on this board so not sure where to inject the voltage

[SMDFlea]

Re: Acer Swift SF314-55G, MI4FA MB REV:2.1 BoardView file and Schematic diagram

post pictures of both sides of the board while you are waiting for someone else to post the schematic in your schematic request thread.

Post good clear pictures of the DC in area,both sides
.

[IamPritesh]

Re: Acer Swift SF314-55G, MI4FA MB REV:2.1

Attached board images. one of them shows the impedence we have on the coils

[mon2]

Re: Acer Swift SF314-55G, MI4FA MB REV:2.1

See attached to get started. It is from the v1.4 of the logic board but looks to be the same as yours.

Measure the resistance of the DCin mosfets - WITHOUT power.

Often the 2nd mosfet is damaged.

Remove all power / no battery.

Meter in resistance mode.

Measure the resistance of each of the 2 x dcin (Q8800 / Q8801) mosfets as follows:

Source (1-2-3) & drain (5-6-7-8)
Source (1-2-3) & gate (4)
Gate (4) & drain (5-6-7-8)

Post each measurement and the meter scale used.

Repeat for the next mosfet.

[IamPritesh]

Re: Acer Swift SF314-55G, MI4FA MB REV:2.1

Thank you so much . Will check these first thing in the morning as lab is closed now.

[IamPritesh]

Re: Acer Swift SF314-55G, MI4FA MB REV:2.1

Resistance of DC IN MOSFETS

Q8801
D --> S = 639 MΩ
S --> G = 100 KΩ
D --> G = 639 MΩ

Q8801
D --> S = 1206 MΩ
S --> G = 100 KΩ
D --> G = 1305 MΩ

[mon2]

Re: Acer Swift SF314-55G, MI4FA MB REV:2.1

The 100k readings are of concern.

Remove the second mosfet off the logic board and check if the s-g reading is still 100k. If yes, check the first mosfet that is still soldered on the board.

Often, the second mosfet will bring down the resistance reading of both dcin mosfets. Likely, the 2nd mosfet needs to be replaced.

[IamPritesh]

Re: Acer Swift SF314-55G, MI4FA MB REV:2.1

I removing the mosfet i checked the resistence between S to G and it shows OL. Can you also share the 1.4 version of boardview and schematic if possible. I also checked the Charging IC and did not find any low impedance. Just not sure where the shorting is and where to inject 1 Volt.

[mcplslg123]

Re: Acer Swift SF314-55G, MI4FA MB REV:2.1

Most likely the marked component is CLR.

[mon2]

Re: Acer Swift SF314-55G, MI4FA MB REV:2.1

Sorry - unable to locate the BV file for this model.

[IamPritesh]

Re: Acer Swift SF314-55G, MI4FA MB REV:2.1

There is some improvement. After Replacing the second DC in mosfet Q8801 I am able to turn on the system without battery and it runs fine. However with battery connected, the system does not turn on. DC_IN connector voltage drops to 0V

[Sephir0th]

Re: Acer Swift SF314-55G, MI4FA MB REV:2.1

To get a better overview we need a full measurement of the charging controller a) with out battery and.b)with battery plugged in. Something must be wrong in charging section or maybe faulty diode before charging controller VCC for example.

[mon2]

Re: Acer Swift SF314-55G, MI4FA MB REV:2.1

The battery mosfet should be inspected and checked with resistance mode.

Remove all power. Check the resistance of the:

Source & drain
Source & gate
Gate & drain