Hello all,
I'm stumped on this guy, so wanted to see if anyone has any further ideas:
Intro:
This is an Acer Nitro 5 AN515-55-55M1 with unknown prior history (bought "as-is" on eBay). It charges the battery and powers on from both AC adapter and battery, so I think this rules out main power issues.
Upon attempt to boot, it will "reboot" (meaning powers down and then powers on again) only once, and then stays stuck in a status of lights on / no post / no monitor. Powering on with fn+esc maxes out the fans on first boot attempt, but once it powers down and on again (on its own), fans go back to normal despite holding fn+esc.
All peripherals were tested in another laptop and are known good (keyboard / LCD / RAM / battery / AC adapter).
Edit because I forgot: Visual inspection shows nothing, board appears brand new.
Testing:
I began by testing the main power rails:
19_IN: There and good (19V with adapter)
5VALW: There and good (5V)
3VALW: There and good (3.3V)
1.8VS: There and good (1.8V)
1.2V_VDDQ: There and good (1.2V)
EC_RSMRST#: There and good (3.3V) <- I'm assuming that's correct
PCH_PWROK: There and good (3.3V)
SYS_PWROK: There and good (3.3V) <- That one puzzles me.
The main suspect:
Upon testing VCC_CORE and VCC_GT (cooler off), VCC_GT is there (0.8V or thereabouts), but VCC_CORE is not. I recall measuring around 1.8V on good laptops (measured on PUH2-5), or at least something. Does not appear to be a short either, as resistance to ground measures ~20ohms. CPU does get hot, so that's weird to me as well.
I have no idea what to use to debug further. Schematic shows PUH2-5 are responsible for that VCC_CORE (I think?).
My next step was to replace PUZ1 from a donor board (I think that's the CPU VCC_CORE controller), but I stopped myself since I do not like to just throw parts at a problem. Is there anything else I can do to debug why that voltage isn't coming on? My only other idea is BIOS issue...
Thank you!
I'm stumped on this guy, so wanted to see if anyone has any further ideas:
Intro:
This is an Acer Nitro 5 AN515-55-55M1 with unknown prior history (bought "as-is" on eBay). It charges the battery and powers on from both AC adapter and battery, so I think this rules out main power issues.
Upon attempt to boot, it will "reboot" (meaning powers down and then powers on again) only once, and then stays stuck in a status of lights on / no post / no monitor. Powering on with fn+esc maxes out the fans on first boot attempt, but once it powers down and on again (on its own), fans go back to normal despite holding fn+esc.
All peripherals were tested in another laptop and are known good (keyboard / LCD / RAM / battery / AC adapter).
Edit because I forgot: Visual inspection shows nothing, board appears brand new.
Testing:
I began by testing the main power rails:
19_IN: There and good (19V with adapter)
5VALW: There and good (5V)
3VALW: There and good (3.3V)
1.8VS: There and good (1.8V)
1.2V_VDDQ: There and good (1.2V)
EC_RSMRST#: There and good (3.3V) <- I'm assuming that's correct
PCH_PWROK: There and good (3.3V)
SYS_PWROK: There and good (3.3V) <- That one puzzles me.
The main suspect:
Upon testing VCC_CORE and VCC_GT (cooler off), VCC_GT is there (0.8V or thereabouts), but VCC_CORE is not. I recall measuring around 1.8V on good laptops (measured on PUH2-5), or at least something. Does not appear to be a short either, as resistance to ground measures ~20ohms. CPU does get hot, so that's weird to me as well.
I have no idea what to use to debug further. Schematic shows PUH2-5 are responsible for that VCC_CORE (I think?).
My next step was to replace PUZ1 from a donor board (I think that's the CPU VCC_CORE controller), but I stopped myself since I do not like to just throw parts at a problem. Is there anything else I can do to debug why that voltage isn't coming on? My only other idea is BIOS issue...
Thank you!
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