Legion 5 PRO, 3 boards, same problem, NM-D562 Rev. 3.0 motherboard

[hopkok]

Hi friends, last week I got 3 same boards for repair (NM-D562 Rev. 3.0), same problem, power button light up, but motherboard wont start.

3,3V_alw and 5V_alw, 1,8V_alw and 0,75V_alw presented on all 3 boards, no other voltages. 1,2V missing and if I checked schematic right, I need 1,2V and than can be +3VS and +5VS generated after getting SUSP_N signal from KBC? or vise versa?

I checked for low resistance on coils, no low resistance.

Anyone with same issue like me?

Thanks for any help.

[mcplslg123]

SUSP_N aka SUSP# missing is the most common fault on this mb. has faced same issue multiple times.

Its RYZEN APU which needs reballing. To test just heatup near ryzen for 30-45 seconds(not on top of it) and very likely you will get display.

[hopkok]

Thanks for hint...will try. How about that horrible black epoxy around CPU, is there any good way to lift CPU without pads?

[hopkok]

Hi, I reheated APU, but no change. Can this by KBC issue as well?

[mcplslg123]

Very very unlikely to be a KBC issue. Its very difficult to de solder this apu 'coz of black glue.
Some pcb pads will definitely torn off(specially the side you tried to lift it). however, they are very likely not connected pads.

I still bet for a defective/dry ryzen

[hopkok]

You are right, all 3 boards dead CPU...

[mcplslg123]

Have faced the same issue atlest 10 times on this very board. however, 5 or 6 were fixed.Rest to garbage bin.

[master3112]

Hello friends, can anyone help me?
I have a Lenovo Legion 5 Pro 16ACH6H, Board: NM-D562 REV.3

problem is that there is no +3VALW on the PL6201 and also +0.75VALW on the PL7701. The +3VALW is provided by the PU6201 using PQ6201 and PQ6202. The +0.75VALW may not be present because +3VALW is not present.
The PU6201 is responsible for:
- +3VALW
- +5VALW
- +3VLP
- +5VLP
All but +3VALW are available. The output for +3VALW is activated on pin 6 of the PU6201 from EC. I have 0V here. I have measured the +3VALW rail and found no abnormalities. When I feed the +3VALW rail with 3V3 from the external power supply, I have a consumption of 0.1A. No short circuit or anything. I have tried
- Disconnected the PJ6206 for the +3VALW.
- Already replaced the EC.
Does anyone have an idea why the EC does not enable the +3VALW and +0.75VALW?
THX

[hopkok]

Change PU6201, if not help, PCH in CPU mostly dead, very common...

[master3112]

THX hopkok
I have already replaced the PU6201. There is no enable signal on PU6201 pin6, nor on PU7701 pin11 for +0.75VALW. The EC must somehow know that something is wrong with the PCH and therefore does not activate +3VALW. Which pins does the EC use to get feedback from the PCH and can it be measured by the resistance? I also have the same healthy board here and could compare it. Do you have any experience?

[hopkok]

Check SUSP_N, if not pressented and I think it will not, BAD CPU. Check schematic for SUSP_N. You can try reheat CPU if any change.

[Stevedb]

Did you also try holding pressure sometimes heating doesn't help but what mcplslg says the ryzen apu needs to be reballed this is pain in ass because there is glue underneath. It known issue

[master3112]

The signal is only present on the healthy mainboard when the power button is pressed. It is an output signal from the EC. But is this the reason why the +3VALW is not activated? If I remove the CPU from another board, all voltages are present. So if the PCH should have no contact, I understand that the board does not start. I would be interested to know what is bothering the EC that it is not activating the +3VALW. Does it recognize a wrong resistor or something?

[master3112]

Was the +3VALW not present on one of your defective mainboards where the CPU was defective?

[hopkok]

Not sure...