• Lenovo Ideapad 3 15-IML05 (MB NM-c781 rev:1.0) not starting with battery only

Danes je 3 Februar 2026, 18:42

 [REŠENO] Lenovo Ideapad 3 15-IML05 (MB NM-c781 rev:1.0) not starting with battery only

 Pravila foruma: Klikni tukaj za prikaz pravil na forumu

  1. Naslov teme mora vsebovati: proizvajalca naprave, poln model in kratek opis okvare.
  2. Sporočilo teme mora vsebovati: oznako tiskanega vezja (v primeru popravil strojne opreme), razširjen opis okvare, kaj je bilo preverjeno, zamenjano in/ali izmerjeno, sklep in vprašanje. Če ne morete najti oznake tiskanega vezja, morate prebrati TO TEMO. Če še vedno ne najdete oznake, prosim objavite kakovostne fotografije obeh strani matične plošče - potrebno je odstraniti vse folije in module, ki bi lahko zakrivali te oznake.
  3. Pred objavo nove teme, preberite vse teme v podforumu USPOSABLJANJA, in naredite predhodno diagnostiko na podlagi vsebine teh usposabljanj.
  4. Nalaganje celotnih navodil/shem, BIOS / firmware datotek, ali objavljanje povezav, ki vodijo do drugih spletnih strani s takšnimi datotekami, je SROGO PREPOVEDANO. Lahko objavite le majhen del navodil/shem, ali povezavo na BIOS datoteko v podforumu NEVERIFICIRANE DATOTEKE BIOS/EFI. V eni temi ne smete objaviti več kot eno stran navodil/shem. Datoteka ne sme vsebovati vidnih žigov "zaupno",, e-poštnih naslovov ipd.
  5. V eni temi lahko opišete SAMO eno napravo. Za vsako drugo okvarjeno napravo morate odpreti novo temo.
  6. Zahteve za sheme, boardview, fotografije matičnih plošč, datoteke BIOS-a ali servisne priročnike za storitve NISO DOVOLJENE. Če želite vprašati za katero koli od teh, odprite novo temo v podforumu ZAHTEVA ZA DOKUMENTACIJO & DATOTEKO BIOS/EFI.

#1 Lenovo Ideapad 3 15-IML05 (MB NM-c781 rev:1.0) not starting with battery only

Napisal/-a hussam • 8 Marec 2023, 18:55
Hallo every one,

I have a Lenovo Lenovo Ideapad 3 15-IML05 mother board: NM-c781 rev:1.0
the laptop charges the battery but it will start just with AC adapter plugged in .

with only battery :
V20B+ is present
no voltage at all coils

with AC Adapter the laptop starts normal

-PU1101 : there is no output voltage
pin#2,3,4=7.7v
pin# 9 EN1=0v
pin#8 EN2=0.56v resistance to ground 60Ω (is that normal)



any one have an idea what could cause this problem?

thanks

Re: Lenovo Ideapad 3 15-IML05 (MB NM-c781 rev:1.0) not starting with battery only

Napisal/-a Google Adsense [BOT] • 8 Marec 2023, 18:55

#2 Re: Lenovo Ideapad 3 15-IML05 (MB NM-c781 rev:1.0) not starting with battery only

Napisal/-a matic • 9 Marec 2023, 08:44
Hello!

Measure the voltages to ground on pins 1, 4, 8 of transistor PQ5303 with the battery connected only (without power supply).

#3 Re: Lenovo Ideapad 3 15-IML05 (MB NM-c781 rev:1.0) not starting with battery only

Napisal/-a hussam • 9 Marec 2023, 10:39
Hello matic,

Pin 1,2,3=7.7v
Pin5=7.7v

The laptop charges the battery normally therefore i think this transistor working fine.

#4 Re: Lenovo Ideapad 3 15-IML05 (MB NM-c781 rev:1.0) not starting with battery only

Napisal/-a matic • 9 Marec 2023, 10:55
How about the voltage on pin 4?

Please, post a picture of the sticker on the battery.

#5 Re: Lenovo Ideapad 3 15-IML05 (MB NM-c781 rev:1.0) not starting with battery only

Napisal/-a hussam • 9 Marec 2023, 17:31
Voltage on pin 4 is =13.7 v
Here is also the battery Photo
Slika

#6 Re: Lenovo Ideapad 3 15-IML05 (MB NM-c781 rev:1.0) not starting with battery only

Napisal/-a matic • 9 Marec 2023, 21:16
hussam napisal/-a:-PU1101
pin#8 EN2=0.56v resistance to ground 60Ω (is that normal)
That's definitely not normal. Have you measured the resistance with the main battery disconnected from the board?

Also measure the voltage to ground on pin 8 of PU1101 with the power supply connected.

#7 Re: Lenovo Ideapad 3 15-IML05 (MB NM-c781 rev:1.0) not starting with battery only

Napisal/-a hussam • 9 Marec 2023, 21:44
I have forgot to disconnect the battery when i measured pin 8
Resistance to ground on pin 8 is 770Ω.

With AC adapter connected pin8 = 1.5v

#8 Re: Lenovo Ideapad 3 15-IML05 (MB NM-c781 rev:1.0) not starting with battery only

Napisal/-a matic • 9 Marec 2023, 22:00
hussam napisal/-a:Resistance to ground on pin 8 is 770Ω.
This resistance is still much too low.

hussam napisal/-a:With AC adapter connected pin8 = 1.5v
This voltage is also too low.

Remove the chip PU1101 from the board and remeasure the resistance to ground on pad 8 on the place of this chip. If the resistance will be high (in kΩ or greater), replace the chip PU1101.

#9 Re: Lenovo Ideapad 3 15-IML05 (MB NM-c781 rev:1.0) not starting with battery only

Napisal/-a hussam • 9 Marec 2023, 22:08
Pu1101 is removed. Pin 8 is still 700ohm

#10 Re: Lenovo Ideapad 3 15-IML05 (MB NM-c781 rev:1.0) not starting with battery only

Napisal/-a matic • 9 Marec 2023, 22:18
This resistance is much too low.
Please, post a clear picture of the chip PU1101 board area with a nearby surroundings (with the chip PU1101 removed from the board).

#11 Re: Lenovo Ideapad 3 15-IML05 (MB NM-c781 rev:1.0) not starting with battery only

Napisal/-a hussam • 9 Marec 2023, 22:26
Slika

#12 Re: Lenovo Ideapad 3 15-IML05 (MB NM-c781 rev:1.0) not starting with battery only

Napisal/-a matic • 10 Marec 2023, 07:54
Please, post a clear picture of the same area from the other side of the board.

#13 Re: Lenovo Ideapad 3 15-IML05 (MB NM-c781 rev:1.0) not starting with battery only

Napisal/-a hussam • 10 Marec 2023, 18:15
Slika

#14 Re: Lenovo Ideapad 3 15-IML05 (MB NM-c781 rev:1.0) not starting with battery only  [REŠENO] 

Napisal/-a matic • 10 Marec 2023, 21:23
Measure the resistance between the point "A" and pin 8 of chip PU1101.
Slika

#15 Re: Lenovo Ideapad 3 15-IML05 (MB NM-c781 rev:1.0) not starting with battery only

Napisal/-a hussam • 10 Marec 2023, 21:30
Problem solved.
Pr1107=1Mohm was defective. After replacing it the laptop starts normally from the battery.
Thanks matic for your help

Podobne Teme
  Lenovo IDEAPAD 3IML05 Motherboard GS452/GS552/GS572 NM-C781 NO BATTERY CHARGING  [REŠENO]
Lenovo Ideapad 3 15IML05 NOT TRIGGER MB : GS452/GS552/GS752 NM-C781 Rev :1.0
Lenovo Z510 motherboard ailza NM-A181 Rev 1.0 problem with battery
  ASUS FX504G motherboard DABKLGMB8D0 REV: D battery not charging  [REŠENO]
Dell XPS 9300 13” motherboard FDQ30 LA-H811P rev 1.0 works with battery only
[BIOS DATOTEKA] BIOS LENOVO IDEAPAD S145-15IIL NM-C711 REV.:1.0

Kdo je na strani

Po forumu brska: 0 registriranih uporabnikov in 2 gostov

_______________________________
Vse pravice pridržane. Nepooblaščeno kopiranje vsebine te spletne strani ali njenega dela je strogo prepovedano.
Vse blagovne znamke, izdelki ali storitve, objavljene na tej spletni strani, pripadajo njihovim zakonitim lastnikom, so avtorsko zaščitene in se uporabljajo samo v informativne namene.