Lenovo ideapad 330ICH - Dead, no volts on coils

[Nagyesz]

Hi everyone, I replaced this motherboard because it was important to get it working, but it's been with me for a very long time. Now I finally have time to figure out what the problem is,
I've never encountered something like this before;

No charging light, full dead

Lenovo Ideapad 330-17ICH

• PL3102: 5 ohms
• PL3001: 3.2 ohms
• PL3101: 2 ohms
• PL5801: 3.5 ohms
• PL5501: 270 ohms
• PL701: 35 ohms
• PL501: 146 ohms
• PL503: 390 ohms
• PL402: OL (0.27V) +5VALW_P
• PL301: OL
• PL401: OL (0.03V) +3VALW_P

+ Dc-in mosfet @PQ311 pin 5 20v, pin 1-4 0V , @PQ312 no volts
+ PR301 to GND 2.5 Ohms (!)

Link to boardview: https://badcaps.net/forum/troublesho...need-schematic

[Nagyesz]

UPDATE: I've identified the overheating component. It's either the PC526 or the PQ501.


PC526 and 25,26 1.5Ohms (VDDQ_VIN)

PJ508 jumper also 1.5Ohms

Now I will seperate PJ508 to check which rail has the short

[Stevedb]

Yes your main powerrail is not running and is shorted pr301 is probably the current sensor not . First check from currentsensor you have no short to the coils. Then if you find directly short then you know with which powerrail is shorted. If none then is injecting time 1v 3A on current sensor.

[Nagyesz]

Thank you for your advice.

• pr301 to PL3102 7.5 ohms
• pr301 to PL3001-2-3 4.5 ohms
• pr301 to PL3201 15.9 ohms
• pr301 to PL5801-2-3 3.9 ohms
• pr301 to PL701 36.8 ohms
• pr301 to PL501 147 ohms
• pr301 to PL503 41 ohms
• pr301 to pl3101 4.5 ohms
• pr301 to PL5501 266 ohms
• pr301 to PL402 OL
• pr301 to PL301 OL
• pr301 to PL401 OL
• pr301 to PL502 OL

What now?

[Nagyesz]

On 1V 3A
PR301 takes 0.6A and it fluctuating to 0.5A

[Nagyesz]

Nothing is warming up, any further ideas on how to figure out why I don't have a main power rail?

[Axis937]

MB Fuse, adaptor, DC in wire?

[Nagyesz]

I will try injecting the 1v again soon, also here's a picture of the affected area;

[Axis937]

What happened to PQ3101 and PQ3102 as well as the coil? was it removed intentionally by you? Bcoz the solder left behind on PQ3101 on the looks like its shorting. I could be totally wrong about this. Do note that i am a super newbie and am learning as well.

[Nagyesz]

I didn't touch it. Most motherboards have several versions, so it might seem like something is missing from the board, but that's how they are from the factory. The motherboards are manufactured first, and the various components are not on them by default.
That's why the motherboard number is important, and just the model is not enough.

[Nagyesz]

UPDATE: I've identified the overheating component. It's either the PC526 or the PQ501.


PC526 and 25,26 1.5Ohms (VDDQ_VIN)

PJ508 jumper also 1.5Ohms

Now I will seperate PJ508 to check which rail has the short

[Nagyesz]

After separating PJ508, the short is on the VDDQ_VIN line, 1.2 Ohms.
The short disappeared at PC526. PQ501 is the next suspect, AON7380_DFN8-5.

Should I replace the heating mosfet right away?

Also PU501 (controller ic) is suspect.

What is the next logical step?

[Nagyesz]

Before I removed the mosfet for measurement, I took a closer look at the capacitors and found a leaking capacitor.

I replaced it, turned it on, and it works.