Lenovo Legion 5 15ARH05H, NM-D281 Rev: 1.0 not work with the battery

[abobek zum]

So, for 230W, the measurement is correct; for 180W, it is not. However, I think there is no point in focusing on the charger anymore. Try doing what Mon2 suggested, and perhaps you will notice some anomaly.

In my case, which could also be helpful for you, I was focusing on the SMBUS between the EC, the battery, and the BQ. I posted all the data that I got (for comparison purposes). I analyzed that data with AI, and it seems to be OK. So, the issue lies somewhere around the BQ chip (HW issue) or in the EC software—where, even if it gets the feedback from the battery, it is not accepting it for some reason (that could be another lead for a potential issue in your case, due to the fact that you replaced the EC chip).

MTT97 , did you program the new EC chip, or did you write it with FF and look for autoprogramming from the main BIOS? I am not familiar with that MB, so I don't know if this EC supports autoprogramming.

As for me, I have already tried two different BIOSes, and I programmed the IT8227E for each case individually. The behavior is the same. Based on that, I will focus on the HW, so now I am going to replace the capacitors and resistors around the BQ chip one by one, including the MOSFETs, even if the measurements are OK for them.
Last resort will be looking for EC dump which works with exactly that type of the battery .....

[MTT97]

So, for 230W, the measurement is correct; for 180W, it is not. However, I think there is no point in focusing on the charger anymore. Try doing what Mon2 suggested, and perhaps you will notice some anomaly.

In my case, which could also be helpful for you, I was focusing on the SMBUS between the EC, the battery, and the BQ. I posted all the data that I got (for comparison purposes). I analyzed that data with AI, and it seems to be OK. So, the issue lies somewhere around the BQ chip (HW issue) or in the EC software—where, even if it gets the feedback from the battery, it is not accepting it for some reason (that could be another lead for a potential issue in your case, due to the fact that you replaced the EC chip).

MTT97 , did you program the new EC chip, or did you write it with FF and look for autoprogramming from the main BIOS? I am not familiar with that MB, so I don't know if this EC supports autoprogramming.

As for me, I have already tried two different BIOSes, and I programmed the IT8227E for each case individually. The behavior is the same. Based on that, I will focus on the HW, so now I am going to replace the capacitors and resistors around the BQ chip one by one, including the MOSFETs, even if the measurements are OK for them.
Last resort will be looking for EC dump which works with exactly that type of the battery .....

The IT8226E-192 i got off Ali was already ''pre-programmed'' for my board, so when i soldered it on the board, it did indeed boot but could also been empty and was auto programmed. Yet i bought a cheap programmer off Ali, erased the chip and the laptop was able to auto program the chip by itself but still didn't solve the issue. My final attempt i erased the chip again and had someone to extract the EC file from the bios and then written it manually into the EC chip but same issue as before again. I spent a lot of time and money on this board which doesn't even have great specs tbh (i5 9300h + 1660ti), i'm waiting for a new multimeter, other equiptment before i continue this repair just a bit more before moving on.

[abobek zum]

I think I found the rootcause. Its a PU2001 (RT6585CGQW - 3Vand5V driver) + speciific PwrSeq on this board. This chip is damaged in specific way. There is leak of voltage to the ugate + shorted Ugate and source of Hiside mosfet (PQ2001) on 3VALW rail. So at the end you have follow situation:
- When MB is powered by battery only there is a leak on 3VALWS and I have there 1.2V.
- With the charger this leak is 3.4V which is really close what you should get on this rail.
According to PwrSeq. with battery only for S5 stage, 3V and 5V ALW is OFF. S5 stage with charger, 3V and 5V ALW is ON and here I think is the reason why MB did not detect this specific short when powered with charger cause EC immediately send EN signal for PU2001 for 3V and 5 ALWS + the leak is very close to the nominal voltage on this rail and it is not detect or the current sens in the charger circuit is less sensitive than the battery one. PGOOD is pulled up to 3ALW.

I will confirm that when Richtek arrives and I will be back from vacation.

[MTT97]

I think I found the rootcause. Its a PU2001 (RT6585CGQW - 3Vand5V driver) + speciific PwrSeq on this board. This chip is damaged in specific way. There is leak of voltage to the ugate + shorted Ugate and source of Hiside mosfet (PQ2001) on 3VALW rail. So at the end you have follow situation:
- When MB is powered by battery only there is a leak on 3VALWS and I have there 1.2V.
- With the charger this leak is 3.4V which is really close what you should get on this rail.
According to PwrSeq. with battery only for S5 stage, 3V and 5V ALW is OFF. S5 stage with charger, 3V and 5V ALW is ON and here I think is the reason why MB did not detect this specific short when powered with charger cause EC immediately send EN signal for PU2001 for 3V and 5 ALWS + the leak is very close to the nominal voltage on this rail and it is not detect or the current sens in the charger circuit is less sensitive than the battery one. PGOOD is pulled up to 3ALW.

I will confirm that when Richtek arrives and I will be back from vacation.

RT6585BGQW is the first thing in my suspect list to replace, followed by BQ24780SRUYR. When i received the laptop and plugged in the charger, i noticed that the RT6585BGQW was getting immediately hot, way too hot to even touch. It didn't take me long to find out that the +3VLP was shorted to ground. I then removed EC > short was gone > replaced EC > still no short > laptop now comes on but wont work if battery is plugged in.