G74A motherboard shuts down

[bjhawfam]

Re: G74A motherboard shuts down

Now when I go back and check voltage I see that PLTRST# is not present when checking against pin 44 at the mini card location will continue to dig around..

[piernov]

Re: G74A motherboard shuts down

If the PLTRST# signal is not present, the BIOS will not start to run.
Check for CPU VCore first.

[bjhawfam]

Re: G74A motherboard shuts down

I did check and I don't have voltage to CPU...

[bjhawfam]

So no cpu_vcore and sys_pwrok comes and goes ( Sometimes it gets power and sometimes it don't)...

[bjhawfam]

So no cpu_vcore and sys_pwrok comes and goes ( Sometimes it gets power and sometimes it don't)...

Disregard on the sys_pwr (fixed)..

[bjhawfam]

Re: G74A motherboard shuts down

Just wanted to give an update for those who may run into the same issue.. I BELIEVE there's possibly a short to ground on the vcc_rail.. I'LL Spend more time later on it.. ...(EDIT) After checking there is a short to ground..

[Thedoc298]

Re: G74A motherboard shuts down

I do have an update on this matter...

The new ITE8987E chips arrived and I replaced it today... With a new bios in place and after the ITE was soldered on I powered the laptop on and found it in the exact state as the original post.. With a new eight pin bios chip and a different g74a bios downloaded onto it,, and with a new ITE8987E chip (blank) the laptop still powers on for a second and than back off... Interestingly, I can tell you that in fact the ite8987e is programmed automatically.. With the new chip in place I created a blank 128mb file and I wrote it to the ITE via the svod programer, however, the blank file was over written automatically when powered back on... So now, either I have two bad bios (8 pin ) files or the problem lies elsewhere.

Had the same thing happning to GA-970a-ds3p. In the end it was the cpu. Had an older cpu with same footprint, dropped it in and good to go.

[bjhawfam]

Re: G74A motherboard shuts down

Good to hear you fixed yours.... If this 8th Gen CPU is shot, The one thing I don't do is replace CPU's by de-soldering them from the board... Miss the older CPU's that you could remove and replace...

When I get bored I'll try and locate the short to ground.. So far I removed a few SMD's and the short still remains.. I just hope the previous owner didn't try heating the CPU....

[Agent24]

Re: G74A motherboard shuts down

Is it a dead short or some few ohms? CPU itself will show low ohms even when OK, but not dead short.

[bjhawfam]

Is it a dead short or some few ohms? CPU itself will show low ohms even when OK, but not dead short.

Not just a few ohms. I'll try and isolate or narrow it down. Hopefully there will be no other issues. Thanks, I'll check back when I have more.

[bjhawfam]

Re: G74A motherboard shuts down

Turns out,,, it is with out a doubt a short to ground somewhere in that circuit, finding it will be a headache. Not sure if I'll spend much more time as all the components are showing the same failure due to the short.. I cant see any visual signs that would help single out a short... Thanks to all that helped and shared their ideas....

[latinphoenix7]

Turns out,,, it is with out a doubt a short to ground somewhere in that circuit, finding it will be a headache. Not sure if I'll spend much more time as all the components are showing the same failure due to the short.. I cant see any visual signs that would help single out a short... Thanks to all that helped and shared their ideas....

Sorry for that, but I certainly think CPU is bad/damaged. I know It's hard to detect the problem. However, you should notice some OVERheat on it in a very short time (when the power button is pushed
). Put a drop of isopropyl alcohol on die and you'll see...

[alas3376]

Re: G74A motherboard shuts down

need boardview of this and EC dump , plz

[KvnTM]

Re: G74A motherboard shuts down

need boardview of this and EC dump , plz

Post your request in BIOS/Schematic Requests and don't hijack an old thread.

[12gitari]

Re: G74A motherboard shuts down

i have G74a which is showing only the charger led and nothing else... most coils have no voltage what could be the most suspected problem?

[sarry86]

MineMine too has same problem, all those caps and coils are shorted to ground and I have tried to remove mosfet and caps and testing them to no available, did you find what shorted the vcc core to ground? Or is it the cpu that is gone? 😭

NB: I have 3 volts, 5 volts and 1.01volts

[sarry86]

MineMine too has same problem, all those caps and coils are shorted to ground and I have tried to remove mosfet and caps and testing them to no available, did you find what shorted the vcc core to ground? Or is it the cpu that is gone? 😭

NB: I have 3 volts, 5 volts and 1.01volts

I have an update to the issue, I have come to realize that there's no 3 voltage on pin 11 of the ITE8987E ic, the 3V_ALW is there but doesn't reach the SIO ic

[mcplslg123]

MineMine too has same problem, all those caps and coils are shorted to ground and I have tried to remove mosfet and caps and testing them to no available, did you find what shorted the vcc core to ground? Or is it the cpu that is gone? 😭

NB: I have 3 volts, 5 volts and 1.01volts

It may not be a short. Cpu Vcore area and VCCGT area will show low resistance for onboaard cpu. What is the exact resistance to GND??(Meter should be in ohms mode and at lowest scale)

[sarry86]

It may not be a short. Cpu Vcore area and VCCGT area will show low resistance for onboaard cpu. What is the exact resistance to GND??(Meter should be in ohms mode and at lowest scale)

Thanks for responding, 16 ohms around smd caps and 4~5ohms around coils

[mcplslg123]

Thats not a short-its normal.