Hi, a blown sound IC would be possible. This can sometimes happen as it did on my Toshita possibly due to ESD on an exposed port causing muddy audio but have also had a dead motherboard caused by this, fortunately got lucky this time and it was on a separate board. This IC on many laptops also does double duty as an SD slot interface and handles certain low level functions so its absence *may* bring it back up at least partially.
I think that you really need to remove the sound ic, but you must measure the impedances, I also think that the impedance should be measured on the diode mode between the audio ic and the PCH. I ask you to have a clear picture of the entire motherboard so that we can identify the circuits and components . My respect and greetings to you from Egypt.
It appears that that manufacturer's IC ALC269 with the "crab" logo is damaged internally. I would check each pin of that IC that is connected to an end terminal of a passive component for shorts. As an example: Pins 13, 18 and 19 are each connected to their respective resistor. Pin 18 and Pin 19 to their corresponding smd ceramic capacitor? Does the DMM show or indicate that at least one of the mentioned pins is shorted? So why continue? Let's replace that IC. I personally believe, without being a chemist, that lighter fluid is much more flammable than isopropyl alcohol (IPA) but each of these passive components would have to be soaked (moistened) individually, which due to their small size is extremely difficult (perhaps with a surgical needle). The thermal camera would detect it accurately if the component is solitary in one area of the PCB. When they are connected in parallel (2 - 4) sometimes it also focuses precisely on the culprit. That laptop is totally similar to the W1415A model from manufacturer ATVIO used here in North America. Thanks for sharing. All the best.
Perhaps the customer added another pair of external speakers with higher impedance (he wanted louder sound) and the ALC269 Audio IC, before dying on its own, wanted to eliminate someone to accompany it and eliminated the Second Input Mosfet. I know it sounds crazy, but if you think about it a little...lol
For test purposes sometimes you measure "backwards" ie meter + to ground. This shows if there is a dead short or just a diode drop. Sometimes you can also see a capacitor charging as well.
I have the same laptop which failed turning on after running a driver update app. I guess this is due to an incorrect firmware update. Are you able to backup & share the bios file for the laptop? Thank you
Hi, a blown sound IC would be possible.
This can sometimes happen as it did on my Toshita possibly due to ESD on an exposed port causing muddy audio but have also had a dead motherboard caused by this, fortunately got lucky this time and it was on a separate board.
This IC on many laptops also does double duty as an SD slot interface and handles certain low level functions so its absence *may* bring it back up at least partially.
I think that you really need to remove the sound ic, but you must measure the impedances, I also think that the impedance should be measured on the diode mode between the audio ic and the PCH. I ask you to have a clear picture of the entire motherboard so that we can identify the circuits and components . My respect and greetings to you from Egypt.
Did you happen to take a diode mode or resistance measurement on the gates of the MOSFETs? I know that sometimes the gates get shorted.
To be clear, you were measuring the MOSFETs in Diode Mode, even though the multimeter graphic showed Volt Mode.
It appears that that manufacturer's IC ALC269 with the "crab" logo is damaged internally. I would check each pin of that IC that is connected to an end terminal of a passive component for shorts. As an example:
Pins 13, 18 and 19 are each connected to their respective resistor. Pin 18 and Pin 19 to their corresponding smd ceramic capacitor? Does the DMM show or indicate that at least one of the mentioned pins is shorted? So why continue? Let's replace that IC.
I personally believe, without being a chemist, that lighter fluid is much more flammable than isopropyl alcohol (IPA) but each of these passive components would have to be soaked (moistened) individually, which due to their small size is extremely difficult (perhaps with a surgical needle).
The thermal camera would detect it accurately if the component is solitary in one area of the PCB. When they are connected in parallel (2 - 4) sometimes it also focuses precisely on the culprit.
That laptop is totally similar to the W1415A model from manufacturer ATVIO used here in North America.
Thanks for sharing. All the best.
Perhaps the customer added another pair of external speakers with higher impedance (he wanted louder sound) and the ALC269 Audio IC, before dying on its own, wanted to eliminate someone to accompany it and eliminated the Second Input Mosfet. I know it sounds crazy, but if you think about it a little...lol
Hello, can someone tell me why in diode mode the red probe is on ground? A short circuit in one sense where another remains a short circuit!
For test purposes sometimes you measure "backwards" ie meter + to ground. This shows if there is a dead short or just a diode drop. Sometimes you can also see a capacitor charging as well.
I have the same laptop which failed turning on after running a driver update app. I guess this is due to an incorrect firmware update. Are you able to backup & share the bios file for the laptop? Thank you
When I press the power button or the charger is connected the blue power led turns on but nothing happens the screen is black.
I would remove the Audio IC to see if that's the problem
High friend which model of Webcam you are using for video recording
Hi friend, I use iPhone 11 for video and images and I have a Yizhan 38MP FHD camera for the sections where you see me soldering.
Best Quality 😍
@@BstAfricanElectronicsSurgeryApologies I forgot to mention, I scan the motherbaords in with a flatbed scanner epson V600.