Lenovo Idepad 320-15AST - no screen on battery

[jajo17]

Hi everone
I have this craptop. AMD CPU. Motherboard model: DG425/DG525/DG725 NM-B321.

After battery replace (it has wear level 96.5% - no charging at all) and screen replace it seems that this laptop is working, charging. OS installed, driver, bios updated, etc...

But it does not work on battery, it turns on, ON button led and Num Lock led are on, fan spinning after while, but not screen. It's frozen. But if I connect charger then, it starts normally after short while.

I noticed, that replace battery (it is not new, but used, wear level 45%, charging normally) is not same type and capacity as old battery was, but same shape and same connector. Can be this source of problem or it is on motherboard, some power good signal ?

On photo is new battery, later I attach old battery.

Schematics here https://www.badcaps.net/forum/showthread.php?t=116545

[jajo17]

Re: Lenovo Idepad 320-15AST - no screen on battery

Here are both batteries on one photo, bottom battery is old, extracted from notebook before repair.

Replacement battery:
Type: 2ICP6/55/90 (L14L2P21), 3968mAh, 7,56V

Old Battery:
Type: L16M2PB1, 4000 mAh, 7,5V

Can be source of problem in wrong battery ?

[mon2]

Re: Lenovo Idepad 320-15AST - no screen on battery

See attached.

Connect your power adapter and battery.

Meter in DC volts (20v or higher is ok).

Measure the voltage to ground of each pin on the battery connector.

Post each measurement.

[jajo17]

Re: Lenovo Idepad 320-15AST - no screen on battery

Thank you for your reply.
In the meantime, I found that the laptop doesn't run on battery at all, the screen goes dark, the power button is still lit and the laptop freezes when I disconnect the AC In when it's on. When I reconnect the AC power, it reboots itself (after a non-correct shutdown).

Voltages are (AC In present, batt connected, power off or on have same voltages):
1,2 8,5 V
3 3,3V
4 3,3V
5 0,3V
6 0V
7,8 GND

Voltages are (AC In disconnected, batt connected, power on):
1,2 7,9 V
3 3,3V
4 3,3V
5 0,3V
6 0V
7,8 GND

Huh, more news, when I was measuring on battery mode only it took some time, after 4 about minutes of measurement notebook suddenly continue to boot, screen light up, but after about 1 minutes, same state as before, black screen, power on led is shining, freeze. After about 3 minutes begin this cycle again, but it seems holding power on on battery, I see Windows desktop, battery show about 1 hour charge remaining.. holly crap.

So I tried power cycle on battery, it spends about 30 second with black screen and then normal booting and after 2 minutes on battery it restart itself. It is like random generator

[jajo17]

Re: Lenovo Idepad 320-15AST - no screen on battery

On battery, when only power led is shinig, then there are these voltages values:

+5VALW, on PJ605, 5,1 V
+3VALW, PJ 602, 3,3 V
+3VL and +3VLP, PJ603 3,3 V

ALW_PWRGD, pin 9 from PU602, always 0V, even when succes boot, open drain output, position PR606 from+3VALW not used, resistance to 3VALW above 1mega ohm. Same on PU 601, seems taht board does not use this signal at all.

APUALW_PWRGD 2,9V on batt, 3V on AC

+APU_CORE, PL2202 0V, then ok

[mcplslg123]

Re: Lenovo Idepad 320-15AST - no screen on battery

Bios has code for battery support and not all battery with similar specs are supported by particular bios-So it may be the new battery is simply not supported by this mb bios. try with exact replacement before probing further.