Lenovo ThinkPad L580 Liquid damage

[jiyo]

Hi,
I have a Lenovo ThinkPad L580 (board EL480 EL580 NM B461 Rev 1.0) with liquid damage. Corrosion was found in several parts of the board. I have cleaned it and inspected for damaged components.

Charger light turns on when connected. Battery charges. Power button led turns on when pressed. Fan is not spinning and I have no video.

Present power rails
B+
+5VALW
+1VALWP
+5VTPC ---->reading 4V though
+VL_3.3V
1.8VALW

Missing power rails
2.5V
+1.2V
+VCC_CORE
+VCC_SA

I've found thas SYSON and VR_ON signals are not present, which explains the missing power rails.

Any ideas why these signals could not be present and how to continue ?

[kalilinux25]

Re: Lenovo ThinkPad L580 Liquid damage

Hi,
I have a Lenovo ThinkPad L580 (board EL480 EL580 NM B461 Rev 1.0) with liquid damage. Corrosion was found in several parts of the board. I have cleaned it and inspected for damaged components.

Charger light turns on when connected. Battery charges. Power button led turns on when pressed. Fan is not spinning and I have no video.

Present power rails
B+
+5VALW
+1VALWP
+5VTPC ---->reading 4V though
+VL_3.3V
1.8VALW

Missing power rails
2.5V
+1.2V
+VCC_CORE
+VCC_SA

I've found thas SYSON and VR_ON signals are not present, which explains the missing power rails.

Any ideas why these signals could not be present and how to continue ?

please check the +3VL_EC +3VALW

[jiyo]

Re: Lenovo ThinkPad L580 Liquid damage

Hi kalilinux25, thanks fou your reply.

+3VL_EC is reading 3.35V
+3VALW reads 3.385V

[kalilinux25]

Re: Lenovo ThinkPad L580 Liquid damage

Hi kalilinux25, thanks fou your reply.

+3VL_EC is reading 3.35V
+3VALW reads 3.385V

can you please post the resistance to gnd of all coils?

FORMAT

COIL NAME - RESISTANCE

Example
PL101 - 100k

PLT_RST#-
EC_ON -
MAINPWON_EC-
SUSP-
PCH_SYSPWROK
PCH_PWROK-
EC_RSMRST#
AC_PRESENT-
KBRST# -

[jiyo]

Re: Lenovo ThinkPad L580 Liquid damage

Thanks again kalilinux25,

I've measured:

PL102 154 KΩ
PL801 26.7 KΩ
PL610 61.4 Ω
PL408 20.9 Ω
PL401 7.1 Ω
PL406 7.1 Ω
PL403 10.8 Ω
PL202 58.5 KΩ
PL403 490 KΩ
PL802 27 KΩ
PL301 178 Ω
PL203 56.8 KΩ


PLT_RST#- 0V
EC_ON - 3.35V
MAINPWON_EC- 3.35V
SUSP- 0V
PCH_SYSPWROK 0V
PCH_PWROK- 0V
EC_RSMRST# 3.334V
AC_PRESENT- 0.02V
KBRST# - 0.001V

[jiyo]

Re: Lenovo ThinkPad L580 Liquid damage

Coils seem to be ok. Any ideas how to continue ?
Thanks

[mon2]

Re: Lenovo ThinkPad L580 Liquid damage

AC_PRESENT- 0.02V

Attach the power adapter and confirm this signal line again. This is not a valid voltage if the power adapter is connected.

[jiyo]

Re: Lenovo ThinkPad L580 Liquid damage

Hi mon2,
When the power adapter is connected AC_PRESENT reads 3.33V

[mon2]

Re: Lenovo ThinkPad L580 Liquid damage

Revise the measurements of the voltage to ground from post #5 with the adapter connected.

[jiyo]

Re: Lenovo ThinkPad L580 Liquid damage

Revise the measurements of the voltage to ground from post #5 with the adapter connected.

The measurements are all the same with the power adapter connected, except for AC_PRESENT which reads 3.3V.

[jiyo]

Re: Lenovo ThinkPad L580 Liquid damage

I've checked the current sensing resistors for coils PL411 and PL406 just to be sure but it doesn't seem related since PU401 is not being enabled by EC.

[jiyo]

Re: Lenovo ThinkPad L580 Liquid damage

I've also noticed that when battery and power supply are connected the power led blinks three times when power button is pressed.

[jiyo]

Re: Lenovo ThinkPad L580 Liquid damage

I've made some progress. I replaced the CMOS battery and could start the computer. All power rails are present now and it is booting to the operating system.

But it only remains on for about 45 seconds, then it shuts down suddenly. This happens with battery only, power adapter only or both connected.

Does anyone know how to troubleshoot this ?