Asus X540UB no vcccore

[lapfix]

Model :Asus X540UBR
M/b: NX540UBR Rev 2.0
Problem: turn on when PSU cable is inserted, consumption 0.106 amp .No display.

Observation:
1. No liquid spill or corrosion observed.
2. 3v/5v alw present.
3. 1.2/+vtt/+2.5v present
4. 1.0VSUS present

Diode mode value :

Pl 8901 = 05.16v
Pl 8701 = 0.354v
Pl 8702 = 0.258v
pl 8600 = 0.358v
Pl 8302 = 0.059v
Pl 8103 = 0.007v
Pl 8102 = 0.007v
Pl 8101 = 0.011v
Pl 9101 = 1.030v
Pl 9100 = 0.030v

So No vcccore , no +nvvdd , no vccgt , noFBVDDQ.

I have flashed Main with official dump,still same.

All power sequence voltages are present until PLT_RST ; No DDR4_DRAMRST is observed.

Can we confirm that :

PCH or CPU is faulty !!
OR is there any others measurements that must be taken...thank you.

[mcplslg123]

Re: Asus X540UB no vcccore

With Asus always check powergood signals.

[Sephir0th]

Re: Asus X540UB no vcccore

First, you can't have 1V at PL9101 in diode mode and almost nothing at PL9100 at the same time. It's just another phase of the same rail.

Second, except measuring data rails, it is usually a bad idea to check power rails in diode mode because it is hard to compare caused by the difference of this function in the various existing multimeters. Ohms mode would be way better for that. Maybe you can add these values.

And like mcplslg already told, check at least Powergood from the VRM and RAM supply and if there is something suspicious, you need to dig more deeper from there.