Thanks piernov,
indeed, I just read it on the logiwiki. So I guess the CPU gave up after all (or I killed it). That is very sad.
I think I will just still measure around a bit and then slowly let it go...
Thanks anyway for all your help!
shortcut7000
New Member
Last Activity: 09-08-2022, 03:45 PM
Joined: 08-10-2021
Location: NRW
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Re: Acer Aspire E5-772G fails to reach ALL_SYS_PWRGD
Thanks piernov,
indeed, I just read it on the logiwiki. So I guess the CPU gave up after all (or I killed it). That is very sad.
I think I will just still measure around a bit and then slowly let it go...
Thanks anyway for all your help! -
Re: Acer Aspire E5-772G fails to reach ALL_SYS_PWRGD
Hey, thanks for keeping this thread alive!
The resistance to ground of 1D35V_CPU_VDDQ_S3 is almost 0 Ohm. It is the same as holding the multimeter probes together.
As a reference I also measured the resistance of 1V_CPU_CORE which is around 1 Ohm which should be normal.
Thanks!
Edit: Actually, what I suspect is the following: Since mosfet PU4902 got shorted after raplacing PU4901, the 1.35V rail might have seen the 19V_DCBATOUT which probably killed the CPU. But I do not...
Last edited by shortcut7000; 09-08-2022, 02:53 PM.Leave a comment:
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Re: Acer Aspire E5-772G fails to reach ALL_SYS_PWRGD
I tried now to isolate the short to ground behind coil PL4901.
I opened the jumpers PG701-706 and unfortunately the short is on the side towards the CPU. To be specific: 1D35V_CPU_VDDQ_S3 is shorted to ground.
Does anybody know if there is still a small chance that this CPU is not dead and how to find it out? There are still some caps on that side, but I did not yet dare to do any voltage injection to check them. Also I am not quite sure if injecting such a low voltage would result in any component...Leave a comment:
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Re: Acer Aspire E5-772G fails to reach ALL_SYS_PWRGD
Ok, some progress here, but no good news:
First I replaced PU4901 which resulted in a completely dead laptop.
Then I realized that PU4902 (one of the mosfets of the 1.35V rail) got killed (shorted). I replaced it.
Then some success: the power LED stayed on after pressing the power button and after a while the fan started spinning full speed. Battery was charging. However, no display and AFTP11 (H_CPUPWRGD) still 0V always.
After some powering on and off I am now back to the same...Leave a comment:
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Re: Acer Aspire E5-772G fails to reach ALL_SYS_PWRGD
Ok, I did some more research on PU4901 (1.35V regulator) and PU4801 (1.05V regulator).
The voltages are as follows:
[B]PU4901 (1.35V)[/B]
pin1 (GND) = GND
pin2 (PWR_VTT) = 1 pulse after PWRBTN
pin3 (GND) = GND
pin4 (PWR_VDDQ_VTTREF) = 1 pulse after PWRBTN
pin5 (PWR_VDDQ_SENSE) = 1 pulse after PWRBTN
pin6 (PWR_VDDQ_FB) = 1 pulse after PWRBTN
pin7 (PWR_VTT_EN) = 1 pulse after PWRBTN
pin8 (PWR_VDDQ_EN) = 1 pulse after PWRBTN
pin9 (PWR_VDDQ_TON)...Leave a comment:
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Re: Acer Aspire E5-772G fails to reach ALL_SYS_PWRGD
Thanks guys for the swift responses! Really amazing how reactive this forum is!
And yes, I would like to rule out everything else before trying a reflow.
Being not an expert, I am not completely sure if I understand the power sequence in the schematic correctly.
To me it looks like 19V, 5V and 3.3V are all fine and it must indeed be something going wrong when trying to enable the 1.35V or 1.05V rails.
I will try to investigate a bit more around PU4901 when I am back on Thursday....Leave a comment:
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Acer Aspire E5-772G fails to reach ALL_SYS_PWRGD
Hi everyone,
I have an Acer Aspire E5-772G with mainboard: Wistron Brook BH 14276-1M
Schematics are in this post: [url]https://www.badcaps.net/forum/showpost.php?p=1020782&postcount=2[/url]
Boardview .brd file I found here: [url]https://drive.google.com/file/d/15-nvu44jdnXonuJ79AoKG_iKw6L76hDj/view[/url]
The laptop is not powering on.
When pressing the power button, the power LED quickly flashes once and then goes off.
System seems to try running the power up sequence for 10 seconds getting stuck at step 6 [1.05V or 1.5V rail] before... -
Re: New Members - please post your introductions here
Greetings! Great forum!
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Re: New Members - please post your introductions here
Hi everyone. Greetings from Germany.
This forum rocks!
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