Lenovo Ideapad 5 14ARE05 LA-J701P - wyłacza się po kilku sekundach

Płyta LA-J701P zmarła po omyłkowym dotknięciu lutownicą do kabelka baterii. KBC zostało wymienione, płyta po wciśnięciu power za pierwszym razem włącza się, pojawiają się wszystkie napięcia i staje na prądzie 0.22A i po kilku sekundach wyłącza się. Następna próba włączenia to już prąd 0.03-0.05 na ok sekundę i brak napięć na 3 cewkach zasilających procesor. Bios programowany 2 wsadami które wcześniej działały w tej płycie. Z pomiarów na KBC wygląda że brakuje napięcia VGATE(jest tylko 0.15V). Zachowanie identyczne na zasilaczu jak i baterii.

Hello!

Measure the resistances to ground on all coils.

PL301- 5 kOhm
PL1802- 9,6 kOhm
PL602- 28.6 Ohm
PL805- 3 Ohm
PL804- 3 Ohm
PL803- 5,9 Ohm
PLM1- 83 Ohm
PLB1- 85 kOhm
PL501- 14,2 kOhm

How about the coil PL602?

I corrected my answer, there is no PL802 coil only PL602.
I'm interested in the VGATE voltage, according to the diagram, it should appear after +APU_CORE_SOC. However, there is no VGATE marking anywhere in the diagram, there is only an indication of pin 36 of KBC EC_THERMTRIP#

baner81 написав:zmarła po omyłkowym dotknięciu lutownicą do kabelka baterii.

Which wire exactly did you touch?
Did you touch this wire and any other component on the board at the same time?

Batt+ with EC_SMCA and maybe EC_SMDA.

Possible defective components PUB1, UEC1, UT1.

Machine написав:Possible defective components PUB1, UEC1, UT1.

UEC1 was changed.
PUB1 - rather not, because it works on the battery and charges it.

baner81 написав:PUB1 - rather not, because it works on the battery and charges it.

Does the machine turn on and boot into the OS with the battery?

Set your multimeter to the diode test mode and measure the voltage drops to ground on pins 12, 13 of charger chip PUB1 (with the battery disconnected from the board).

PUB1
pin 12 - 0.468
pin 13 - 0,494

Machine does not post, does not read the bios. Without the bios chip, it behaves identically. According to the power diagram, if the KBC does not receive the VGATE signal (pin 36) it will not issue the PCH_PWROK signal (pin32) which will block the start procedure. I'm right?

baner81 написав:According to the power diagram, if the KBC does not receive the VGATE signal (pin 36) it will not issue the PCH_PWROK signal (pin32) which will block the start procedure. I'm right?

We don't know that, because there are inconsistencies between the power sequence diagram and the schematic.

Measure the following voltages to ground, when the machine is turned on (power consumption is 0.22A):
- On coils PL602, PL1802, PLM1.
- On pin 3 of transistor Q5.
- On pins 8, 14 of chip U10.
- On pin 6 of chip U19.
- On pin 1 of chip PU251.
- On pin 20 of chip PUM1.

Transistor Q5 pin count:

PL602 - 0,766 V
PL1802 - 1,798 V
PLM - 1,198 V
Q5 PIN 3 - 1,798 V
U10 PIN 8 -5,1 V
PIN 14 - 3,34 V
U19 PIN 6 - 0,765
PU251 PIN 1 - very short peak 2,5V, next stay on 0,46V
PUM1 PIN 20 - 0,589 V
------------------------
PU251 PIN 6 EN - very short peak 3,3V, next 0V

Which resistor is present on the board - PR251 or PR256?

PR251 points were connected, I cut and connected PR256, but nothing changed except a stable voltage of 2.5V from PU251

Try to reflash the KBC chip with programmer.

KBC I bought a new one with programming service, I can't connect to KBC via SVOD3

Post a screen of Svod connections (Setup -> Edit motherboard).

I have tried 2 options:

The option 2 (LA-J701p naeem test ok) seems fine. The 32-pin FFC cable must be aligned with pin 1 of the keyboard connector on the motherboard (the pin close to the JIO1 connector).

- Did you connect the ground cable between the motherboard and Svod programmer?
- Do you get a message "Check pins ok"?