Acer A315-34-P1SQ Huaqin NB8609 Rose GL NB8609 MB Fault

[menderland]

Any help would be aprreciated on the following (Apollogises for any language related mistakes).

As the title states I have a Aspire a315-34 with a NB8609_PCB_MB_V4 board. The laptop does not powers on. I have 5V present on L1 and 3.3V on L2. When I plug in the charger, I see, with the thermal camera, that L8 mosfet rises temperature, cools down and then the ethernet controler glows.

Any suggestions on how to proceed would be helpful.

Schematic ---> https://www.badcaps.net/forum/showth...55#post1216455

[mon2]

Re: Acer A315-34-P1SQ Fault

Remove all power. Meter in resistance mode. Check the resistance to ground of L8.

[menderland]

Re: Acer A315-34-P1SQ Fault

mon2 thank u for spending time reading & posting.

Measurements are:

Vin floating between kΩ and MΩ
ΕΝ: 162kΩ
PGOOD: 9.9kΩ
VCC: 1,54MΩ
LDO3:0.78MΩ
FF:19.15kΩ
BOOT: 14.7MΩ
LX (INDUCTOR): 78Ω
VOUT:78.2Ω

[mon2]

Re: Acer A315-34-P1SQ Fault

Can you link the schematic if available in the schematic forum?

VOUT:78.2Ω

This is a low resistance but may be normal if the regulator is with a low output voltage.

[menderland]

Re: Acer A315-34-P1SQ Fault

Thank u for following. I cannot say I really understand. Unfortunately, the schematic is not available in the forum (i think only the cad file I was able to find). I was able to find it from another source however but as a newbie I need to read how to understand it (lots of videos and reading).

[mon2]

Re: Acer A315-34-P1SQ Fault

Post the topside markings of the mosfet that is heating up so we can locate the same in the schematic.

[Vesko356]

Re: Acer A315-34-P1SQ Fault

Unfortunately, the schematic is not available in the forum (i think only the cad file I was able to find). I was able to find it from another source...

If the schematic for your machine is not available here at Badcaps but you are able find it elsewhere, you can share it at the Schematic sub-section, and link the thread to this topic.

.

[menderland]

Re: Acer A315-34-P1SQ Fault

mon2 photo attached

[menderland]

Re: Acer A315-34-P1SQ Fault

vesko356 hello. schematic is viewed by web explorer as is someones shared drive file. no download or print is available.

[mon2]

Re: Acer A315-34-P1SQ Fault

I think that we are referencing the same schematic but mine is locked to the paid viewer and service.

The part that is heating up is not a mosfet but the actual switching regulator IC @ PU202. The output inductor is @ PL201 and is nearby the same part.

This leg of the circuit is supposed to output 3v3 (+V3P3A) and this resistance is low for this voltage.

This low resistance could be linked to a defective capacitor or perhaps even the main CPU.

Would you have an adjustable power supply that can output 1 volts ? What is the max current supported by the power supply ?

[Vesko356]

Re: Acer A315-34-P1SQ Fault

vesko356 hello. schematic is viewed by web explorer as is someones shared drive file. no download or print is available.

Share the link here.

.

[menderland]

Re: Acer A315-34-P1SQ Fault

mon2 I have an adjustable power supply with max current of 5A.

[menderland]

Re: Acer A315-34-P1SQ Fault

schematic diagram file for Acer A315 Huaqin NB8609 Rose GL NB8609 MB
link: https://drive.google.com/file/d/1555...74lSlwD4y/view

[Vesko356]

Re: Acer A315-34-P1SQ Fault

schematic diagram file for Acer A315 Huaqin NB8609 Rose GL NB8609 MB
link: https://drive.google.com/file/d/1555...74lSlwD4y/view

It's available at the Schematic sub-section ---> https://www.badcaps.net/forum/showth...55#post1216455
I'll add the link in post #1

.

[mon2]

Re: Acer A315-34-P1SQ Acer A315 Huaqin NB8609 Rose GL NB8609 MB Fault

Remove all power / no battery.

Dial up the DC power supply to 1 volt (not higher) and max current you can support.

Inject this DC power supply rail (red lead) onto the inductor you noted as Vout = PL201. Black lead to ground.

As you do this, someone should heat up. Locate the component that is heating up. Ideally it will be a bad / partially shorted capacitor. Do also review if the CPU is warming up under this setup.

[menderland]

Re: Acer A315-34-P1SQ Huaqin NB8609 Rose GL NB8609 MB Fault

mon2 tnx for keeping up. 21mA are drawn and nothing heats up (thermal camera).

[mon2]

Re: Acer A315-34-P1SQ Huaqin NB8609 Rose GL NB8609 MB Fault

Ok. Current is too low to heat up the component.

Carefully, measure the voltage to ground of pin # 6 = EN (for enable) on PU202.

We want to know if this power rail is being enabled or not as it heats up.

Also, what is the voltage to ground at

a) Vout = PL201 inductor ?

b) V3P3A_VCC = pin # 9 (Vcc) of PU202 = power rail for this switching regulator

[menderland]

Re: Acer A315-34-P1SQ Huaqin NB8609 Rose GL NB8609 MB Fault

EN Voltage:3.250V(pin #6)
PL201:3.271 V
VCC:3.256 V