asus gl502vsk no +vccore

[myth77]

This laptop i believe have all voltages...no short, but i can not get +vcccore to rise. On PWM CONTROLLER NCP81205 i have 5v, i have all_system_pwrgnd 3,3V but it is not opening +vcccore. The cpu i7-7700 resistence on +vccore is 2.5 ohm i believe its fine. I get +1,2 volt, i have +vccsa, +vccio but no +vcccore. All other voltage on the board present(gpu, pch, ite...) only +vcccore missing. Already tried two dumb bioses but nothing.
On PWM CONTROLLER NCP81205...... P_SVID_DATA_X1, P_SVID_CLK_X1 are 1V but P_SVID_ALERT#_X1 0V..i dont know is this ok? pins 18,19,20 i have 2V, pins 21,22 0V.
what do i need to get +vccore to open on CONTROLLER NCP81205?
thx
oh and i removed PS8330BQFN for now...because it was getting very hot, but i dont see any relation to this problem.

attached schematic for this model, and boardview for similar model (maybe it helps).

[caspian]

Re: asus gl502vsk no +vccore

If you have measured PU8109, PU8101, and PU8102, you need to report the results to reach a conclusion on this issue.

[myth77]

Re: asus gl502vsk no +vccore

i have...the readings on pins are:
pin 1 5V
pin 2 2V
pin 3 5V
pin 4 5v
pin 5 0v
pin 6 gnd 0v
pin 7 0 v
pin 8 0 v

[caspian]

Re: asus gl502vsk no +vccore

PU8100, PU8101, and PU8102 are not working. So PU8100, PU8101, and PU8102, and their connected Mosfets are the suspects. With a low probability, NCP81205 can be a suspect too.
Personally, I never had success in repairing this kind of problem in CPU_vCore circuits. However, you can try replacing PU8100, PU8101, and PU8102, and their connected Mosfets.

[myth77]

Re: asus gl502vsk no +vccore

PU8109, PU8101, and PU8102 are not working. So PU8109, PU8101, and PU8102, and their connected Mosfets are the suspects. With a low probability, NCP81205 can be a suspect too.
Personally, I never had success in repairing this kind of problem in CPU_vCore circuits. However, you can try replacing PU8109, PU8101, and PU8102, and their connected Mosfets.

ok i will try and report...just to clarify we are talking about pu8101, pu8102 and pu8100(not pu8109)?

[caspian]

Re: asus gl502vsk no +vccore

I had a typing mistake. I edited Post#4.

[caspian]

Re: asus gl502vsk no +vccore

Repair the circuit with your own risk. Because it is possible that the repaired circuit fails and then burns the CPU.

[myth77]

Re: asus gl502vsk no +vccore

I replaced pu8101, pu8102 and pu8100 but the same thing. But, then i read NCP81253 datasheet in details (link below) and according to the datasheet on page 9 for DRVH to go high i need to have EN and PWM high!? En is high but PWM is high if it is above 2.7 vol, but i have 2.0 V. So if i am correct NCP81253 is working fine!? but the question is why PWM signal coming from ncp81205 is not higher then 2V?

https://www.alldatasheet.com/datashe...1253MNTBG.html

[mon2]

Re: asus gl502vsk no +vccore

How are your measuring the PWM signal ? Please note that this is a pulsing line (high / low) so you really need an oscilloscope here since a meter cannot sample the lines fast enough to supply the proper measurement. That is, it is very possible that you are really > 2v but the meter is not able to sample the pulsing line fast enough.

[myth77]

Re: asus gl502vsk no +vccore

Update, i found that on NPC81205 signals are on:

pin40 P_SVID_DATA_X1 is 1 vol,
pin 42 P_SVID_CLK_X1 also 1 vol,
but pin 41 P_SVID_ALERT#_X1 is 0,08 vol... i think this should be also 1 vol.
Also checked H_CPU_SVIDALRT# and it is 1 vol.

Help where to look ? this indicates cpu dead?

[caspian]

Re: asus gl502vsk no +vccore

Probably, the CPU and PCH are fine and the problem is somewhere in the CPU VRM circuit.

[loic2907]

Re: asus gl502vsk no +vccore

Did you find a solution?

[rediii]

Re: asus gl502vsk no +vccore

Did you find a solution?

you mostly need to reball or replace the cpu. end of story

[mcplslg123]

Re: asus gl502vsk no +vccore

SVID_ALERT# pulled low is often a sign of bad cpu(Not PCH)