ACER Spin SP113-31-P6NZ not working on Battery

[mferna14]

Hi All, I am working on ACER Spin SP113-31-P6NZ ( board # Ironhide_APL 16835-1M) boots up well but does not work on main Battery & sometimes shits downs automatically. As soon as I unplug the Power adapter jack, Bang!!! it turns off. In Windows 10 it shows the battery is present & charging. I even checked the battery voltage by shorted BAT_G to GND & it shows 16 volts. Below I will share the voltages of the BQ24737 IC. What may be the problem & if anyone willing to share the Schematics, would be great. Thanks in advance.

These voltages are when the Battery is plugged in & the side voltages are without the battery connected.
1 ACN 19.5 19.5
2 ACP 19.5 19.5
3 CMPOUT 0.01 0.01
4 CMPIN 0.02 0.02
5 ACOK# 0.00 0.00
6 ACDET 2.6 2.6
7 IOUT 0.03 0.03
8 SDA 3.2 3.2
9 SCL 3.2 3.2
10 ILIM 3.2 3.2
11 BM# 0.2 0.2
12 SRN 2.7 6.2
13 SRP 2.7 6.2
14 GND 0.00 0.00
15 LODRV 0.00 0.00
16 REG 6.07 11.8
17 BTST 5.8 11.6
18 HIDRV 2.7 6.2
19 PHASE 2.7 6.2
20 VCC 19V 19.0

[mon2]

Re: ACER Spin SP113-31-P6NZ not working on Battery

sometimes shits downs automatically

Spicy food ?

Is the ACDET voltage correct? With the battery only, you see this value?

[mferna14]

Re: ACER Spin SP113-31-P6NZ not working on Battery

Thanks mon2., I do not know the correct voltage of ACDET? BY THE WAY what voltage should be out here???

[mon2]

Re: ACER Spin SP113-31-P6NZ not working on Battery

Sorry for being vague - it is a bit of a loaded question.

I believe that 2v6 is fine but questioning why there is 2v6 if you have only the battery connected.

If you mate the external power adapter, then there is a VIN from the external adapter and a resistor voltage divider will scale this high voltage down to a safe value. The 2v6 sounds ok to me.

See attached on a random schematic found using the same TI charger IC.

When you remove the external DC adapter but using only the battery, I would not expect any voltage on ACDET pin.

Can you confirm this ? Perhaps my misunderstanding of quick reading of this thread.

[mferna14]

Re: ACER Spin SP113-31-P6NZ not working on Battery

You are really helpful... Yes, you are right, I will check accordingly the schematic diagram & inform you.. Thanks

[mferna14]

Re: ACER Spin SP113-31-P6NZ not working on Battery

I checked the voltages, on ACDET pin 6, 2.6V is present when DC adapter is attached but one I remove it from the DC-in jack, then NO VOLTAGE present on Pin 6, which is correct. & once I remove the Adapter pin, the Motherboard goes dead again & does not operate on battery at all, but battery shows clearly in Win 10 & shows charging icon too!! Now I think you will get an idea. & one more thing I noticed when I reset the battery from the on-board RESET button, on battery terminals the voltages raises to 16V & then slowly drop down.

[mon2]

Re: ACER Spin SP113-31-P6NZ not working on Battery

See attached.

1) the full example schematic that uses this IC is attached.

2) the datasheet of a very close charger IC from TI (735) is attached.

The logic board you have is probably very close to the posted sample schematic.

Of immediate concern is that the LODRV pin is always @ 0v. This does not look correct.

The charger IC may be defective but start with these suggestions:

1) Remove the battery.

2) Use only the external adapter to power the logic board. Do you see any voltage on the LODRV pin of this charger IC ? It should not be @ 0v.

Consider to carefully measure directly on the charger IC to rule out any possible broken PCB traces.

3) After the above check, remove all power (no battery / no adapter).

Meter in resistance mode (2k scale is ok).

Check the resistance between:

source (1-2-3) & drain (5-6-7-8)
source (1-2-3) & gate (4)
gate (4) & drain (5-6-7-8)

for the first 2 mosfet that most likely are present on your logic board. These are the typical dual mosfets that mate the external DC adapter to the charger IC.

Then check the switching HIGH & LOW side mosfets in the same manner.

Finally, the BATTERY MOSFET needs to be checked.

Post all your measurements.

We are checking for low resistance on any of the above tests which will likely mean a defective mosfet that needs to be replaced.

BQ24737
https://www.aliexpress.com/item/3289...c00nV1Am3&mp=1

[mferna14]

Re: ACER Spin SP113-31-P6NZ not working on Battery

Thanks for all the inform. I have BQ24737, I just now replaced it too, no difference. Right now I am draining the voltage of the main battery with a .5 watt filament bulb. Let me see whether it will charge or not after a discharge. Then later I will check all the above sequence what you wrote in detail.

[mon2]

Re: ACER Spin SP113-31-P6NZ not working on Battery

ILIM @ 3v2 sounds high - unless there is only a single resistor to the +3ALW rail.

See attached. Do you have a similar 2 resistor voltage divider on the ILIM pin?

Without power, measure their resistance.

[mferna14]

Re: ACER Spin SP113-31-P6NZ not working on Battery

Yes mon2 the voltage out here should be less than 1V., where as in my case its always shows 3.2V & this board has only ONE resistor 100K so it seems to be the right volt on ILIM. Before this resistor volts is 3.3 & after this resistor going to pin 10 is 3.2v. From where is this signal generated from???

[mon2]

Re: ACER Spin SP113-31-P6NZ not working on Battery

Pin #10 on the charger IC is an input. You (the engineer) have to define a predefined voltage for this pin using an external source.

For this logic board, it appears to be the 100k pull-up resistor to +3v3.

The datasheet for the 735 charger IC notes that if the voltage is > 1v6 (believe I read) then the limit feature is disabled.

If you are confident that there is only a single resistor on this pin then it is ok to leave it as-is.

I would review if the mosfets surrounding this component are ok.

[mferna14]

Re: ACER Spin SP113-31-P6NZ not working on Battery

MOSFET are all good, I re-checked them again & they are fine... Now ACOK is bad.. When the AC adapter is pluged, this PIN 5 should be ZERO & still shows 3.2V, it should ONLY be 3.2 volts when on battery & AC NOT PLUGGED in... What you say??? I think here the problem lies. This is what I have to find, why it does not turn off to ZERO. & in this board the ACOK line come directly from the IO chip KB9028Q pin 110. Is this chip Programmable or its ready to solder to the board???

[mon2]

Re: ACER Spin SP113-31-P6NZ not working on Battery

No. ACOK is an output pin.

It is open drain and will have a local pull up resistor.

If the pin is HIGH, this indicates the AC is ok.

If low, AC is NOT ok.

Details in the 735 datasheet above.

[mferna14]

Re: ACER Spin SP113-31-P6NZ not working on Battery

I was just checking a youtube video & according to this charging chip BQ24737 ACOK should be LOW. No doubt this is an OPEN DRAIN, it has NO pull-up resistor & Pin 5 of BQ24737 is directly going to pin 110 of the IO chip., but at pin 5 it has be LOW when AC power is connected. I even took a similar model ACER Spin motherboard & this PIN is low when AC power is connected (Different charging chip & reflects the BQ series IC on his chart). This guys made a chart for his students, check the screenshot, it a good reference for all the BQ series chips. Hope it helps & if some else can kindly put in their thoughts into this. Are we right???

[mferna14]

Re: ACER Spin SP113-31-P6NZ not working on Battery

In my case whether AC power is connected or not connected, PIN 5 is always High. Here is another reference according to the guys BQ series chart.

[mon2]

Re: ACER Spin SP113-31-P6NZ not working on Battery

Thanks for the correction. So the 735 and 737 do differ, at least on the ACOK pin operation.

On the other Acer model, what is ACOK pin voltage when the adapter is not connected but using battery only?

[mcplslg123]

Re: ACER Spin SP113-31-P6NZ not working on Battery

I confirm ACOK on BQ24737 should be low on adapter only.

[mferna14]

Re: ACER Spin SP113-31-P6NZ not working on Battery

When using the battery, see the photos of the charging chip BQ24707, you will notice in GREEN that there is 3.2V when ONLY on battery & when on AC power this pin 5 should turn to GND (0V) according to the Chip schematics/designing. Thanks for all the information.. Now I have to check whether I have this IO KB9028Q, program it & then see what's the result.

[mon2]

Re: ACER Spin SP113-31-P6NZ not working on Battery

Can you confirm the markings on the charger chip ?

The first post notes BQ24737. The last post references BQ24707.

[mferna14]

Re: ACER Spin SP113-31-P6NZ not working on Battery

Yes, I have confirmed, same BQ family & if you see that guys charts it totally reflects to these 2 chip. You are seeing correct.. The one which I am working has BQ24737 & the other ACER Spin which is 100% working has this charge chip BQ24707. The pins are named the same on both diagrams, so this is why I questioned you. & now I checked the defective ACER Spin, with ONLY the battery connected it should shows voltages on Pin 5 but there is absolutely no voltages out here.