Acer Aspire A315-56-37qb mobo fried after programmed bios

[AppleLover123]

Hello guys,

i've got this Laptop from ebay the bios was bricked. I bought it a few weeks ago and flashed it with
a CH341A Programmer first (Bios.bin attached) all that went good my bios worked and it booted up afterwards.
Now i used it and wanted more memory so i went from a 4 GB 1Rx16 to a 16GB 1Rx8 .
But it wont boot up with the new ram stick that i checked before in another laptop then i thought it was a good idea to flash the bios again
with the same .bin so i dissasembled the laptop and took out the mobo and flashed the bios again (same way i did it before) . Then i reassembled everything
like it was before and wanted to start the laptop the powerlight comes up and the fan rotates but no picture for a long while because i let it sitting for 10 minutes.
I thought the bios version is just to old and turned the laptop off to put the old stick in but as i wanted to turn on the laptop the fan doesnt rotates anymore and the powerlight turns off after 3 seconds.
Then i measured the board and all the voltages are present but not the 3.3v line anymore i checked if it was shorted and now on pl302 yesterday there was 2.5 ohms and now there are 69.1(on 2) and 13.7(on 1) ohms on it but why?

Bordview attached Please post a link to the schematic/boardview - https://www.badcaps.net/forum/troubl...f-this-section

Hope you guys can help me!

[AppleLover123]

Now thats interesting:

When i turn on on the laptop (on pin 1) there are 2.66v and (on pin 2) the 3.3v so they are present i just dont know how that circuit works.
My idea is that i fried the cpu while i flashed the bios because pin 8 of the bios chip is connected directly with the 3.3v primary and the cpu on 5 pins.
Now am i right or does it have a chance to live?

[AppleLover123]

Hey guys,

i have a Acer Aspire 3 A315-56-37QB.
The Problem is following:

I wanted to expand ram so i installed a 1Rx8 16GB DDR4 Memory Stick
that i tested in another laptop before.
The Laptop started fan was spinning but no picture.
Then i had the great idea to flash the bios again (i flashed it before because i got it from eBay
and it worked after that) . Now after i flashed it again the Laptop power led Lights up for around 5 seconds
and shuts down (no fan spinning,but charging fine) .
I already posted a threat on badcaps about my problem but i received no answers.
Tried different bios files from requests but none of them made a difference (do you think i should do a clean me?)
none of them worked. I measured the voltages and all are present.
The way i flashed the bios:

First time after i put in the ram-
Flashed with a SOC8 on my Ch341a on-board

Second time-
Took the chip out put it onto my programmer and used (this bios file attached in the post)
and soldered it back after.

Now whats interesting is that while the bios chip was out it did the same thing like with it.
Is it probably the sio because ist not communicating with the bios (also because the fan doesnt spin) ?

Boardview and schematic attached Link to schematic/boardview https://www.badcaps.net/forum/troubl...c-acer-a315-56

S/N: NXHS5EG00C1230D2D93400
SNID: 12305397734
MOBO: LA-J801P FH5LI Rev 1.0 (with i3-10th gen) model

Thanks for helping

[mon2]

Any difference if you power up with all ram removed? Any post beeps to indicate the ram is missing?

[AppleLover123]

Any difference if you power up with all ram removed? Any post beeps to indicate the ram is missing?

No completely dead. But it cannot do the post beep because it has soldered ram cant it?
Before it was doing the 5 seconds on off thing if i plugged the charger with no picture it beeped (indicating it recognized the charger).
But now it's not so i'm really assuming it is the sio that has corrupted firmware or what do you think?
Also i made a misstake while i flashed it one time because of the ram : i disconnected the battery (also the bios battery) thats why i'm assuming the sio went corrupt.

[mon2]

Certainly confirm that the BIOS image is suitable for your logic board.

Confirm that the DCin power jack is not the fault. When you mate the external power adapter, do you measure the adapter voltage on the logic board? Is it stable? If the logic board power is shutting down then there may be a shorted part onboard or the local regulators believe there is a short. This can be due to missing parts on the current sense leg of each regulator. That is, the regulator measures the minute voltage drop across the current sense resistors. If a part on this loop circuit is missing then the regulator will assume the worst - that power went in but fell off the board on the next leg of the current sense resistor so power it down immediately.

Suggest to remove all power. Meter in resistance mode. Measure the resistance to ground on each and every inductor on the board. Checking for low resistance values that may indicate a shorted part. Then confirm the current sense resistor paths for each regulator. Measure directly on the regulator pin and compare this total resistance to the schematics.

[AppleLover123]

Certainly confirm that the BIOS image is suitable for your logic board.

Confirm that the DCin power jack is not the fault. When you mate the external power adapter, do you measure the adapter voltage on the logic board? Is it stable? If the logic board power is shutting down then there may be a shorted part onboard or the local regulators believe there is a short. This can be due to missing parts on the current sense leg of each regulator. That is, the regulator measures the minute voltage drop across the current sense resistors. If a part on this loop circuit is missing then the regulator will assume the worst - that power went in but fell off the board on the next leg of the current sense resistor so power it down immediately.

Suggest to remove all power. Meter in resistance mode. Measure the resistance to ground on each and every inductor on the board. Checking for low resistance values that may indicate a shorted part. Then confirm the current sense resistor paths for each regulator. Measure directly on the regulator pin and compare this total resistance to the schematics.

So the BIOS image IS the image for my board because i flashed it before and the laptop was working fine with that image that cannot be my problem.
I measured again and i found something very interesting (the sio has 3.3v all okay its not getting hot):

3VALW_PRIM is 3.3v when powered on before there is nothing ( the 3.3v are directly going from the IC over 3V_VLP to 3V_VLP_EC so they are present at anytime)

The crazy thing is that the coil that is connected to the 3VALW_PRIM is 66 ohms when the charger and battery is unplugged but when i plug the charger or the battery the coil is getting to 2.2 ohms not a good sign right( resistnace is going up after turned on)?
The coil of the rail is getting 3.3v at pin 2 but on pin 1 only 2.6v.

One thing that is strange that the 1.2V_LV is only 0.14v when the laptop starts .Resistance is: 18ohms

Otherwise all other Voltages are good the 5v are present at anytime (also at the coil)

The CPU is getting power as soon as the powerbutton is pressed.

So i changed my mind there is a problem at my 3v power rail but what?

[mon2]

Never measure resistance or diode mode test with power to the board. It cannot be done and is dangerous to the meter.

Can you confirm if 3VALW_PRIM is stable on its voltage to ground?

[AppleLover123]

Okay i've understand sorry i'm trying to learn :/

Yes the 3VALW_PRIM is stable when the laptop is on. After the LED turns of the 3.3v are present a few seconds afterwards and then it's going down to 0v.
On PIN 1 of the coil there is the LX_3V which has around 2.5v it seems it is tending from 2.5 to 2.7v can there be a short on the LX_3V ?

[mon2]

On PIN 1 of the coil there is the LX_3V which has around 2.5v it seems it is tending from 2.5 to 2.7v can there be a short on the LX_3V ?

Yes. This should be a steady 3v3. Remove all power. Meter in resistance mode. Measure the resistance to ground of this coil / inductor. We are checking if the resistance is lower than normal since this buck regulator (takes in a high voltage; outputs a low voltage) is struggling to provide the stable 3v3 output.

What is the resistance in ohms?

[piernov]

No point measuring before the inductor, cheap DMM won't read voltages switching at high frequency properly. 3.3V after means it's clearly working.

[AppleLover123]

What is the resistance in ohms?

So the resistance in resistance mode is over 100 (on my multimeter there's just a 1) ohms i think it is fine. But clearly the supply looses some power but i don't know where it should go? What important things are on the LX Rail?

[AppleLover123]

No point measuring before the inductor

But what could it be otherwise if it works?
I mean it is the only point where could be something faulty right?

[rogfanther]

Just to check something : read again the bios chip, and compare what is read with the original file that you wrote in it earlier. Compare with the operating system tools ( fc /b in windows, for example ). Also, check chip orientation and the solder on the board.

[AppleLover123]

Just to check something : read again the bios chip, and compare what is read with the original file that you wrote in it earlier. Compare with the operating system tools ( fc /b in windows, for example ). Also, check chip orientation and the solder on the board.

Sorry someone put my old post onto my new thats why its confusing. To be clear i already flashed the bios chip with different files not just with my one over and over again. The Bios Chip is in position like the boardview and schematic says.

Yes. This should be a steady 3v3. Remove all power. Meter in resistance mode. Measure the resistance to ground of this coil / inductor. We are checking if the resistance is lower than normal since this buck regulator (takes in a high voltage; outputs a low voltage) is struggling to provide the stable 3v3 output.

What is the resistance in ohms?

Now man i'm so sorry for replying so late !

What i didn't meontioned earlyer is that the ram power supply is only outputting 0.30v instead of the 1.2v at the 1.2VS. I measured at the coil and at PUM1 (the chip thats responsible for the 1.2v and 0.6VSP) .
So because i'm a dumba*s noob working on a selfmade problem i don't know what the 0.6v and 2.5v are doing.
To be mentioned these are not present and also not shorted just not showing up. I don't understand how these work but i guess the ram output has to be 1.2v to power on the 0.6v and 2.5v.

Now what i think is that the chip has an issue providing the voltage and i would order a new one as a lucky guess. But why is nothing shorted on that chip?
PUM1 is not outputting the pgood signal can there be a problem arround the chip also?
I measured the capacitors and the coils resistance and there are 18.5 ohms is that fine?

The last thing i didn't mention is that the 1.8v are present so there's no problem.
As you said at the LX_3V there has to be 3.3v but there are only 2.8v . That the voltage is tending was because i was trembling with my hands.
But 2.8v are not okay as well . The resistance is 59.2 ohms in diode mode.

[loopster]

I don't know whether I understood the whole complex correctly, I just skimmed everything, but you mentioned that "it has soldered ram" in post #5.
Have you considered the possiblity that your onboard ram has gone faulty by sheer coincidence, and that prevents the laptop from working, irrespective of the bios flash issue?

[AppleLover123]

I don't know whether I understood the whole complex correctly, I just skimmed everything, but you mentioned that "it has soldered ram" in post #5.
Have you considered the possiblity that your onboard ram has gone faulty by sheer coincidence, and that prevents the laptop from working, irrespective of the bios flash issue?

I thought about that too but how can i test the onboard ram? I mean if the mobo has faulty on board ram the scenario would be: goes on, fan spinning and no picture. Or in the other case that the ram is taking too much current because it's faulty am i right?

PS: It is a little confusing because a moderator made my old post and the new one together i'm sorry about that.

[rogfanther]

The question for reading the bios chip was to check if the flash operation was successfull, or if some problem could have happened during flashing and corrupt data was written.

Also, can you post clear pictures of the bios chip area?

Those voltage measurements are with the extra memory stick removed, yes ?