Acer No power A4WAB LA-C341P REV 1.0

[kalilinux25]

Re: Acer No power A4WAB LA-C341P REV 1.0

AC_ON has 1.6v , ec_kbrst# 0v , ec_on 3.3v , ec_rst# 3.3v , ec_rtcrst# 0v

[mcplslg123]

Re: Acer No power A4WAB LA-C341P REV 1.0

With a good cmos cell inserted, voltage at JCMOS1 & JCMOS2 pads??

[mcplslg123]

Re: Acer No power A4WAB LA-C341P REV 1.0

Most of the newer acer motherboard's have 3v problem where you get 5V on coil but no 3V on coil even though 3v LDO is present. This is cause of "thermal protect shutdown" circuit. In your case, it is there on pg 38 of schematic. You will find 3V_EN & 3V_EN_R missing(MAINPWON however remains present). The solution with repect to your motherboard is
01.Remove R2626 & R2627
02.Remove D2016
03.Put a jumper between 2 pads of D2016.

Now your dc amp reading should go close up to 0.0020A and there will be 3V on coil.Mb will give display on triggering if there is no other problem.

Tested it on many newer Acer motherboards and this trick works fine. Hope this will help a lot of members here.

[kalilinux25]

Re: Acer No power A4WAB LA-C341P REV 1.0

Most of the newer acer motherboard's have 3v problem where you get 5V on coil but no 3V on coil even though 3v LDO is present. This is cause of "thermal protect shutdown" circuit. In your case, it is there on pg 38 of schematic. You will find 3V_EN & 3V_EN_R missing(MAINPWON however remains present). The solution with repect to your motherboard is
01.Remove R2626 & R2627
02.Remove D2016
03.Put a jumper between 2 pads of D2016.

Now your dc amp reading should go close up to 0.0020A and there will be 3V on coil.Mb will give display on triggering if there is no other problem.

Tested it on many newer Acer motherboards and this trick works fine. Hope this will help a lot of members here.

I tried it sir but the LED and charging light blinks at the same time the ntaking only 4 milliamps

[kalilinux25]

Re: Acer No power A4WAB LA-C341P REV 1.0

I tried to check the U11

[kalilinux25]

Re: Acer No power A4WAB LA-C341P REV 1.0



I got no voltage at the vout of the ic also the susp# has no voltage reading also

[kalilinux25]

Re: Acer No power A4WAB LA-C341P REV 1.0

PWRBTN - 3V
EC_ON - 3.3V
SPOK - 3.3V
3.3VALW - OK
5VALW -OK
SYSON- 3.3V
SUSP# - 0V
EC_RTCRST# - 0V
PCH_ACIN - 0V
PCH_RSMRST# 0V
+3VLP - 3.3V
PLT_RST# 0V

Mobo is taking only around 1miamp
charging led and power led blinking at the same time

[mcplslg123]

Re: Acer No power A4WAB LA-C341P REV 1.0

With a good cmos cell inserted, voltage at JCMOS1 & JCMOS2 pads??

Did you checked this??

[kalilinux25]

Re: Acer No power A4WAB LA-C341P REV 1.0

Did you checked this??

tried sir it has 3v

[kalilinux25]

Re: Acer No power A4WAB LA-C341P REV 1.0

I also tried to flash the ec bin but it nothing changes I use this https://www.badcaps.net/forum/showth...light=la-c341p

[kalilinux25]

Re: Acer No power A4WAB LA-C341P REV 1.0

Board was blinking

Tried
-Flashing ec and Bios Chip
-same issue
@Tried Changing Charger Ic
-Same Issue

Overall it was fixed by a faulty Mosfet

Thanks to all that help me Board now is fully Working

Ive learned a lot here 😇

[kalilinux25]

Re: Acer No power A4WAB LA-C341P REV 1.0

Did you checked this??

I plugg the board with a new battery it wont take any amps battery LED will blink,,

PJP201 with battery connected

PIN
1 GND -0V
2 GND - 0V
3 EC_SMB DA - 3.3V
4 EC SMB CK - 3.3V
5 BATT_TS - 2.0V
6 BATT _ B/L - 0V
7,8 - 14.4V

PR212 Value that supposed to be 100K has value of 451kiloohms

PR212
pin 1 +RTCVCC - 3.1V
pin 2 - BI GATE - 2.9V

[mon2]

Re: Acer No power A4WAB LA-C341P REV 1.0

1) with battery connected; adapter removed; meter in DC voltage mode,

a) what is the voltage reading @ PQ304 - pin 1-2-3 ?

b) what is the voltage reading @ PQ304 - pin 5 ?

c) what is the voltage reading @ PQ304 - pin 4 ?

The voltage from pins #1-2-3 should pass through onto pin #5 to power the logic board. If this is not true, check the mosfet for a possible short.

2) Remove all power; meter in resistance mode.

a) resistance of PQ304 SOURCE to DRAIN ?

b) resistance of PQ304 SOURCE to GATE ?

c) resistance of PQ304 GATE to DRAIN ?

[kalilinux25]

Re: Acer No power A4WAB LA-C341P REV 1.0

1) with battery connected; adapter removed; meter in dc voltage mode,

a) what is the voltage reading @ pq304 - pin 1-2-3 ?

B) what is the voltage reading @ pq304 - pin 5 ?

C) what is the voltage reading @ pq304 - pin 4 ?

The voltage from pins #1-2-3 should pass through onto pin #5 to power the logic board. If this is not true, check the mosfet for a possible short.

2) remove all power; meter in resistance mode.

A) resistance of pq304 source to drain ?

B) resistance of pq304 source to gate ?

C) resistance of pq304 gate to drain ?

p304 - 123 - 14v
p304 - 5 - 14v
pq304 pin 4 - 20v

s to d - 3.9 mohms
d to g - 4.3 mohms
s to g - 2.3 megaohms

[mon2]

Re: Acer No power A4WAB LA-C341P REV 1.0

This case sounds similar to ours for a HP unit we serviced recently.

Originally, every battery we tested would not charge. Then we brought in the very nice stand alone charger tool NLBA1 which confirmed that our replacement battery was deep discharged and was defective. We sent it back to the vendor and after weeks of chats, they replaced the unit with a fresh battery.

The original battery had 800+ charge cycles on it and the NLBA1 was able to charge it without our HP logic board. The logic board could not charge any attached battery.

In the end, thanks to this forum - the issue was that the first mosfet was shorted.

Remove all power. Meter in resistance mode.

Check the usual mosfet readings between SOURCE & DRAIN; GATE & DRAIN; GATE & SOURCE for the first 2 mosfets. PQ302 & PQ303.

If no issue found, you can check PQ305 & PQ306.

Next, with the adapter ON - what are the voltage readings @ +19V_P1 ?

@ +19V_P2 ?

@ PL302, pin # 2 ?

@ PQ304, pin 4 ?

[kalilinux25]

Re: Acer No power A4WAB LA-C341P REV 1.0

@ +19V_P1 20v
@ +19V_P2 20v
@ PL302, pin # 2 20v
@ PQ304, pin 4 ? 0v

[mon2]

Re: Acer No power A4WAB LA-C341P REV 1.0

Remove all power. Meter in resistance mode.

Check the usual mosfet readings between SOURCE & DRAIN; GATE & DRAIN; GATE & SOURCE for the first 2 mosfets. PQ302 & PQ303.

If no issue found, you can check PQ305 & PQ306.

[kalilinux25]

Re: Acer No power A4WAB LA-C341P REV 1.0

Remove all power. Meter in resistance mode.

Check the usual mosfet readings between SOURCE & DRAIN; GATE & DRAIN; GATE & SOURCE for the first 2 mosfets. PQ302 & PQ303.

If no issue found, you can check PQ305 & PQ306.

I found no issues on the first two mosfets

[kalilinux25]

Re: Acer No power A4WAB LA-C341P REV 1.0

hope someon can guide me..

[mon2]

Re: Acer No power A4WAB LA-C341P REV 1.0

Hi. It is quite late here and need my beauty rest but can you summarize the issue with the battery ? What is the exact fault ?

From the above posts, your new battery is @ 14v (this is ok).

The mosfet @ PQ304 is receiving the gate voltage of +6v = 20V. This is ok.

The drain is passing through the voltage from the source @ 14v.

So the logic board should be powered. Is the logic board not working from the battery ?

Or is the fault that the battery is not charging ?

Is the battery confirmed to be 100% ok ? Often, the issue is the battery itself.

Is the battery gauge working inside of Windows? Do you see the charge icon and with the adapter plugged in - the battery level should increase.