Lenovo Ideapad 320-15IKA NM-B452 not charging battery

[jared101]

Lenovo Ideapad 320-15IKA
NM-B452

Hi guys. I've used the forum a lot but never asked questions before. I had a Lenovo come in that was shorted on the 20V rail. I fixed that and thought my job was done until I realized it wasn't charging the battery. Here is what I've checked so far

On the BQ24780SRUYR charging ic
VCC 20V
SMBUS lines
SDA 3.3V
SCL 3.3V
Current Sensing lines
ACP/ACN 2.3 ohms
SRP/SRN 21.2 ohms
REGEN line 6V
PHASE .84V with no battery installed(this may be normal)
PHASE xxV with battery installed voltage is slightly higher than battery voltage.

Originally the battery was completely drained so I charged it with my DCPS. The machine will work on battery power. When the ac adapter is first plugged in the battery icon in the lower right shows that it is charging and it shows the battery filling up over and over for about 10-20 seconds. Then it stops but still shows that the battery plugged up. I do not get a message saying not charging. Feel free to let me know what I haven't checked. I have not tried a new battery yet because this battery seems okay.

[tomodachi]

Re: Lenovo Ideapad 320-15IKA NM-B452 not charging battery

Check to see if DCIN mosfets PQ311 and PQ312 is short or not

[mcplslg123]

Re: Lenovo Ideapad 320-15IKA NM-B452 not charging battery

ACDRV,ACOK,ACDET Voltage??

[jared101]

Re: Lenovo Ideapad 320-15IKA NM-B452 not charging battery

No shorts on DCIN fets

No shorts on DCIN fets

ACDRV 20.3V. BATDRV Same as battery V
ACOK 3.27v BATSRC Same as battery V
ACDET 2.9v TB_STAT .785v
HIDRV Same as battery V BATPRES .298v
LODRV 0v PROCHOT .3mV
BTST 6.85v PMON 10mV
ILIM .79V IDCHG .398v
CMPIN .276v IADP 26V
CMPOUT .520v CMSRC 20V

[piernov]

Re: Lenovo Ideapad 320-15IKA NM-B452 not charging battery

No shorts on DCIN fets

ACDRV 20.3V.

?

[jared101]

Re: Lenovo Ideapad 320-15IKA NM-B452 not charging battery

Hi piernov. I just reread through your sticky on charging circuits. When i think short I think short to ground. Sorry for the noob mistake. PQ311 is definitely bad

PQ311
0 ohm between Drain and source
170 ohm between Drain and gate
170 ohm between gate and source

PQ312
9Mohm between drain and source
OL between drain and gate
OL between source and gate.

I’m not sure if PQ312 is okay or not. After I have replaced PQ311 what V should I see on ACDRV

[mon2]

Re: Lenovo Ideapad 320-15IKA NM-B452 not charging battery

As per the TI datasheet, the gate voltage (ACDRV) should be ~6 volts higher than the source voltage.

So you should see ~25 volts.

[jared101]

Re: Lenovo Ideapad 320-15IKA NM-B452 not charging battery

I did read that but I just wanted to ask. I’m still new to some of this. Now to locate a replacement that won’t take a month to get here.

[mon2]

Re: Lenovo Ideapad 320-15IKA NM-B452 not charging battery

Now to locate a replacement that won't take a month to get here.

Aliexpress is not too bad but yes it *may* take longer than sourcing locally.

See attached. TI has stock of the part at this time of writing. While you are at it, consider to buy drop in replacement mosfets for the same repair. If TI has them in stock, the part will be great as spares for your parts drawer.

I did read that but I just wanted to ask.

I think some datasheets, including this one, are written in a format that only twins can understand. Chargers are a hot (no pun, ok a small pun) topic here.

See my post and the excellent reply from the TI engineer here ( a must read ):

https://e2e.ti.com/support/power-man...114776#4114776

[jared101]

Re: Lenovo Ideapad 320-15IKA NM-B452 not charging battery

Definitely over my head. I think that reply he gave came from the data sheet too. I tried locating that part at www.ti.com but did not see it the first time. I’ll check again later

[tomodachi]

Re: Lenovo Ideapad 320-15IKA NM-B452 not charging battery

Glad you found the problem.

[jared101]

Re: Lenovo Ideapad 320-15IKA NM-B452 not charging battery

Glad you found the problem.

Thanks for helping. You were spot on.

[jared101]

Re: Lenovo Ideapad 320-15IKA NM-B452 not charging battery

Digikey for the win.

[rookieme]

Re: Lenovo Ideapad 320-15IKA NM-B452 not charging battery

Hello team, I am having same charge battery issues with the same model.
The SRN_R line was blown internally at the pcb and the pcb was lifted a bit at that spot.
So far I have cut both lines SRN_R & SRP_R just to be sure and connected them by cable to PR317, replaced PR338, PR328 & PU301, checked PQ311 & PQ312.
ACDET 2,66V
ACOK 3,32V
ACDRV 24,11V
ILIM 0,84V
SDA & SCL 3,33V and connection to kbc & battery
HIDRV 7,44V with battery voltage 5,85V or 7,80V with 6,15V [second battery]
I have orange flashing led 3 times for as long I have a battery connected.

I can find nothing wrong with it, any help will be appreciated.

[mon2]

Re: Lenovo Ideapad 320-15IKA NM-B452 not charging battery

Remove all power and measure the resistance of the current loop but directly at the ic pins for SRN & SRP.

[rookieme]

Re: Lenovo Ideapad 320-15IKA NM-B452 not charging battery

It is 20,16 Ohm

[mon2]

Re: Lenovo Ideapad 320-15IKA NM-B452 not charging battery

Ok resistance.

What is the voltage to ground of BATT_TEMP = pin # 15 (BATPRES#) on the charger IC?

[rookieme]

Re: Lenovo Ideapad 320-15IKA NM-B452 not charging battery

It is 3,33V without battery and 0,30V with the battery connected.

[mon2]

Re: Lenovo Ideapad 320-15IKA NM-B452 not charging battery

What is the voltage to ground of REGN (pin #24 = BQ24780_VDD) ? This should be ~6 volts.

Test with a known good battery. The conditions look ok to charge the battery.

Perhaps the battery is locked.

[rookieme]

Re: Lenovo Ideapad 320-15IKA NM-B452 not charging battery

REGN is 6,02V

The fact is that I have a similar model that has same charger [24780s] and can take either 2 cell or 3 cell batteries [currently has 3 cells] so I tried these 2 cell batteries there and they charge [stable orange led].
After I took the working 3 cell battery and tried at the faulty motherboard one just to confirm that it cannot charge it but it does powers on with it.
I'm wondering if bios could cause such issue.