LENOVO U330 DA0LZ5MB8B0 Quanta LZ5 REV:D

[BlueMidnight]

Re: LENOVO U330 DA0LZ5MB8B0 Quanta LZ5 REV

Okay, so that narrows it down a little.

Working backwards, you can check each of these steps that happen before PLTRST#. All should go high after pressing the power button:

PCH_THRMTRIP#
H_CPUPWRGD
EC_PWROK
SYS_PWROK

[kokono]

Re: LENOVO U330 DA0LZ5MB8B0 Quanta LZ5 REV

Okay, so that narrows it down a little.

Working backwards, you can check each of these steps that happen before PLTRST#. All should go high after pressing the power button:

PCH_THRMTRIP#
H_CPUPWRGD
EC_PWROK
SYS_PWROK

please attention output PL3 ist null Before and after switch on
i think all these signal also are null

[BlueMidnight]

Re: LENOVO U330 DA0LZ5MB8B0 Quanta LZ5 REV

Okay good, you are getting HWPG signal, so it is entering the S0 power state, and the PCH should be getting all its power rails (assuming no broken traces). But the next step is for the board to read the CPU SVID information and then set the CPU core voltage appropriately. And that isn't happening.

So it looks like the problem is somewhere in between those 2 steps. Maybe in or around PU3/PQ2.

Press the power button and check VR_ON / H_VR_ENABLE_MCP on PU3 (pin 8)... it should go high.

If VR_ON does go high:
- Check for resistance to ground on +VCCIN. It should have a somewhat low resistance since it's the CPU power rail. But if it is too close to zero, there may be a short.
- The surrounding components (especially the capacitors and NTC resistor) could be checked.

Otherwise, the next step would probably be to try replacing PQ2. And then PU3 if necessary.

If VR_ON does not go high, then the CPU isn't requesting for its core power rail to turn on.. for some reason.

[kokono]

Re: LENOVO U330 DA0LZ5MB8B0 Quanta LZ5 REV

i changed PQ2 and NOW all things ist OK

[kokono]

Re: LENOVO U330 DA0LZ5MB8B0 Quanta LZ5 REV

Okay good, you are getting HWPG signal, so it is entering the S0 power state, and the PCH should be getting all its power rails (assuming no broken traces). But the next step is for the board to read the CPU SVID information and then set the CPU core voltage appropriately. And that isn't happening.

So it looks like the problem is somewhere in between those 2 steps. Maybe in or around PU3/PQ2.

Press the power button and check VR_ON / H_VR_ENABLE_MCP on PU3 (pin 8)... it should go high.

If VR_ON does go high:
- Check for resistance to ground on +VCCIN. It should have a somewhat low resistance since it's the CPU power rail. But if it is too close to zero, there may be a short.
- The surrounding components (especially the capacitors and NTC resistor) could be checked.

Otherwise, the next step would probably be to try replacing PQ2. And then PU3 if necessary.

If VR_ON does not go high, then the CPU isn't requesting for its core power rail to turn on.. for some reason.

Very thx for all try and your time

[BlueMidnight]

Re: LENOVO U330 DA0LZ5MB8B0 Quanta LZ5 REV

Awesome! Glad the bad part was found.

You're welcome.

[openminded]

Re: LENOVO U330 DA0LZ5MB8B0 Quanta LZ5 REV

hi, just wanted to say thanks for all the detailed info, that helped me a lot with troubleshooting. I think in my case it might have been an issue with the battery. The CMOS battery was 2.2V and I replaced it but that did not help. Might be a powerboard issue too, it's still something that came back, until I was able to boot without battery. Thank you for sharing all the knowledge !