Lenovo Ideapad 3 won't start

[Antonio Distefano]

have a Lenovo V15 ADA05 laptop that fails to power on. I've already tried several troubleshooting steps, including replacing the RAM, running hardware tests, performing a BIOS reset, and even reflashing the BIOS firmware.
When I press the power button, the power LED blinks briefly, the fan spins up momentarily, then stops — and the system remains unresponsive with no display output.
What could be the potential cause of this issue?

[mon2]

Hi. What is the history of this unit?

Issue could be a defective onboard capacitor that is showing a short condition and this event is forcing the local power rail to power down. The name of this website is built upon 'bad caps'.

Perhaps an issue in the power path from the power adapter to the main power rail. With a multimeter we can assist to diagnose the defective part(s) onboard. Would you have one for taking a few measurements?

[Antonio Distefano]

Hi there, my friend. Honestly, I had a quick look with a multimeter at some components and fuses, but I'm not very familiar with reading schematics.
Maybe you could give me a hand with that.

This laptop stopped working all of a sudden — I initially thought it was just a dead battery because the power LED was blinking, so I assumed it was just low charge.
I tried resetting the BIOS and replaced the battery, and surprisingly it worked again for about a week.
But then it completely stopped powering on and hasn't turned on since.

[mon2]

I am guessing that it worked for a week since you replaced the battery. The battery had a pre-charge and the unit ran off the battery. The hints are going back to the common fault of the power path. The power adapter (assuming it is ok and often it is), will mate with DCin mosfets which act like solid state relays to pass the power onto the main rail. If there is a faulty mosfet (usually there are 2 in series), then the battery will not charge. This is why you ran for a week ok, it was all on battery mode only.

We need a good view of the board to hunt for the battery charger IC and the local 2 x DCin mosfets. Then with your multimeter, you can confirm which part is defective. You mentioned that you have a multimeter?

[mon2]

Start with locating the DCin power adapter connector. Share clear pics of the region. Here we can confirm the voltage from the power adapter is actually reaching the logic board parts. Following this check will be the DCin mosfets.

If the voltage on the gate pin of each mosfet is high enough, only then will the power adapter voltage travel onto the main power rail. We know that you were able to run the unit from battery for a week so very likely the fault is pre-charger region. There is a very good article (sticky) above on charger circuits by piernov. A good sedative with solid information.

Using the meter, without power to the board, we can test the mosfets which are the current suspects for your case. Moving forward, you can order the mosfets and have a local cellphone repair shop replace the parts or lean on a local EE student from your college / university who probably will have the tools (and a propeller cap).

[Antonio Distefano]

I actually have a full lab setup at home, so I could definitely handle the repair myself.
I already do soldering work and similar tasks — I usually handle PC and console maintenance, mostly on the software side, but I haven't done much hands-on work with schematics before.

That said, if we can identify the faulty component together, I'm confident I can replace it myself.

I'm not at home right now, but once I bring the laptop back to my lab, I'll inspect the board and send you some clear photos of the area around the DC-in connector and nearby components.

Thanks again for the support — I'll update you in a few hours!

[mcplslg123]

I'll bet more on cracked solder joints under SOC. This is the most common fault on newer lenovo's due to "Low Melting Solder"

[Antonio Distefano]

So, thake a look guy

[Antonio Distefano]

I'll bet more on cracked solder joints under SOC. This is the most common fault on newer lenovo's due to "Low Melting Solder"

Wich one? is this common?

[mcplslg123]

Yes, its very common for newer lenovo's to have cracked solder joints under SOC. the reason is solder used by lenovo.It melts at very low temparature compared to other brands.

So when the SOC heats up, the balls gets cracked underneath-A very usual feature with lenovo's.

I'm betting on this 'coz you have intermittent display. If you have BGA machine try to reflow it a bit(dont use hot air gun).

However, if my doubt is correct,then reflowing wont fix your issue as there is black glue underneath SOC. It needs reballing and thats not easy.

I just highlighted one of the major reason for failure in lenovo's.Your case may be different-so keep digging.

[Antonio Distefano]

mcplslg123 I don't have the equipment for a full SoC reball — I only have a hot air station, not a dedicated reballing machine.
That said, I do have a preheater, a hot air station, and the standard tools I use regularly for hardware work.

Maybe before going that far, mon2 could help me do some basic diagnostics using the multimeter, beyond what I've already checked.
I'm still new to working with schematics — I've never really had to follow them before — so I'd definitely appreciate some guidance.