Acer Not Powering la-k701p

[kalilinux25]

Hi goodday to all , Im having a quite issue, if the PU301 si need replacing because I dont have any parts avalble, and needed it to be ordered overseas.

Unit wont power, no water damage and corrosion, unit was not used for almost a year (customer said)

BOARD: GH5JJ/GH7JJ LA-K701P REC:1C 2021-01-08

MAINPWON 3.3v goes 1.2v every 5 sec


PU301 READING
1.BST- 3V
2,3,4,5 - +19VB_3V- 19V
6. LX_3V - 0V-
7,8 - GND
9. SPOK_3V
10. NC
11. ENLDO_3V - 4.4V STABLE
12.3V_EN -0V
13. 3V_FB - 0V
14.+3VALWP- 0V- not shorted kilo ohms reading 4k
15.NC-
16,17. +3VLPP- 3.3V
18.GND
19,20- LX_3V- 0V


+3VLP 3.3V STABLE
EC_ON
3.3V STABLE
5V_3V_EN 3.3V
PCH_DPWROK 0V
+RTCVCC 3.1 V no cmos connected
3V_EN_R 0v RB16 1k ohms reading resistor ok not shorted on both sides

ON/OFFBTN# 3.3v if pressed goes 0v and back to 3.3v

Link to schematic -> https://www.badcaps.net/forum/troubl...c-or-boardview

[reformatt]

Re: Acer Not Powering la-k701p

Power cycling of the enable is EC not getting a power good from PU301 (or something further down in the power sequence).

Check the boost and feedback circuits first before blaming the IC.

[kalilinux25]

Re: Acer Not Powering la-k701p

Power cycling of the enable is EC not getting a power good from PU301 (or something further down in the power sequence).

Check the boost and feedback circuits first before blaming the IC.

Which feedback circuit sir? sorry for bad english

[chenwei]

Re: Acer Not Powering la-k701p

Placed a year of machine, it is recommended that the replacing PL302 inductance

[reformatt]

Re: Acer Not Powering la-k701p

PC302, PC315, PR306 etc. I could count on one hand the number of inductors I've had fail.

[kalilinux25]

Re: Acer Not Powering la-k701p

PC302, PC315, PR306 etc. I could count on one hand the number of inductors I've had fail.

Hi sir this is what I got
RESISTANCE TO GROUND READINGS
PC302- 2.6Mohms pin 2 to ground
PC305 - non stuff ( not present on board)
PL302 - 3.9k to ground
RB16- 1K value ok
RB17- 1MK ok
PC315- 4.0Momhs
PR303- 150K ok

[mcplslg123]

Re: Acer Not Powering la-k701p

DB1,pin1 MAINPWON present??

[kalilinux25]

Re: Acer Not Powering la-k701p

DB1,pin1 MAINPWON present??

DB1

PIN1 - 3.3V stable sir


Thank You for checking by sir

[mcplslg123]

Re: Acer Not Powering la-k701p

Remove RB16 & RB17 and DB1. Jumper DB1 between both pads. Hope you will have a working machine back.

[kalilinux25]

Re: Acer Not Powering la-k701p

Remove RB16 & RB17 and DB1. Jumper DB1 between both pads. Hope you will have a working machine back.

Thanks sir Ill try and update

[kalilinux25]

Re: Acer Not Powering la-k701p

Remove RB16 & RB17 and DB1. Jumper DB1 between both pads. Hope you will have a working machine back.

Thank You sir , Unit now is fully working at no issue at all, my I ask why do I need to remove those resistor and diode? please illaborate it to me , thanks

[mcplslg123]

Re: Acer Not Powering la-k701p

Thank You sir , Unit now is fully working at no issue at all, my I ask why do I need to remove those resistor and diode? please illaborate it to me , thanks

Glad to know that. Have a look at the schematic and answer lies there. We've just bypassed "thermal protection". Common issue on many acer models-Whatever you do, this protection doesnt go away and i dont know why.

[kalilinux25]

Re: Acer Not Powering la-k701p

Glad to know that. Have a look at the schematic and answer lies there. We've just bypassed "thermal protection". Common issue on many acer models-Whatever you do, this protection doesnt go away and i dont know why.

So means the unit wont tart becasue of the thermal protection.

[mcplslg123]

Re: Acer Not Powering la-k701p

Yes and this trick will help you on many acer boards with same issue and the solution is same-to bypass thermal protection.

[kalilinux25]

Re: Acer Not Powering la-k701p

Yes and this trick will help you on many acer boards with same issue and the solution is same-to bypass thermal protection.

Sir update after 2 days unit response became same, no shorted test voltage on the jumper of DB1 it has 3.3v

[mcplslg123]

Re: Acer Not Powering la-k701p

Perhaps a new fault and unrelated to earlier repair. So need to probe from the beginning.

[kalilinux25]

Re: Acer Not Powering la-k701p

Perhaps a new fault and unrelated to earlier repair. So need to probe from the beginning.

ok sir , 3v and 5v is present as always pwoer button has 3.3v and unit is only consuming 30milliamp and also tried flashing from acer website

[kalilinux25]

Re: Acer Not Powering la-k701p

Fan just turn and stop and unit goes no power no led indicator present

[kalilinux25]

Re: Acer Not Powering la-k701p

Perhaps a new fault and unrelated to earlier repair. So need to probe from the beginning.

3V_EN -3.3v
PCH_DPWROK -0v - not shorted
SLP_SUS# - 0v
PCH_PWR_EN -0v
+1.8VALW - 0v
EC_RSMRST# -0v
AC_PRESENT - 0v
SYSON - 0v
+3VLP_EC -3.3v
+3VLP - 3.3v
AC_IN - 3.2v
LID_SW# -3.3v
SUSP# - 0v RST ( resistance to ground ) 10koms
+5VALW -5.1v
PM_SLP_S3# - 0v
PM_SLP_S4# -0v

[mcplslg123]

Re: Acer Not Powering la-k701p

EC_RSMRST# -0v This is cause of concern. Without RSMRST# present, you cant expect get anything from PCH like PM_SLP_X. Try removing DB2/DB/3/DB4 one by one and see any changes happens or not. However, before RSMRST# 1.05V/1.8V ALW rails should be present.