Acer Nitro 5 3valwp short 1ohm

[mcplslg123]

Re: Acer Nitro 5 3valwp short 1ohm

You didnt shared the final resistance to GND on +3VALW line as well as +1.05V rail before soldering the new PCH. You only said now all re good. If PCH gets shorted on triggering the mb,there is still a short on the mb.

[Thomas8607]

Re: Acer Nitro 5 3valwp short 1ohm

I measured ~6kohm on 3valwp (without LAN and Sound IC)

I don't remember the resistance value on the 1.05V rail (kohm range), I can only say that these voltages appeared when switched on, nothing else (without PCH):
5VALW (5.08V), 3VALW (3.37V), 1.05VALW (1.07V) and 1.8VALW (1.85V)

After a few seconds, they turned off and only 5VALW remained on. When switched on again (keyboard connector 1-2 pins), they appeared again.

The resistance of the new PCH at 1.05V is 50 ohms after soldering

Thank you Sir!

[Thomas8607]

Re: Acer Nitro 5 3valwp short 1ohm

I injected 0.8v to the 3.3v and 1.05v voltages and also to the 1.8v. The heat is generated in the same place in all three cases. Then pch removal again ☹️

I did videos and uploaded to youtube :
https://youtu.be/Zwd2bqZDxmQ
https://youtu.be/rg7CWiP50ao

[Thomas8607]

Re: Acer Nitro 5 3valwp short 1ohm

I removed the pch.
I measured the resistance:
- 3valw: 19,4kohm
- 3v ldo: 30kohm
- 5valw: 66,5kohm
- 1,05v: 34,4kohm
- 1,8v: 30kohm
- cpu vcore: 2ohm. i7 9750h
- cpu pla1: 13,5ohm
- cpu plg1: 4,5ohm
- ram 1,2v: 200ohm
- 2,5v pj2502: 2,8kohm
- plw1: 113ohm
- gpu core 0,8ohm gtx1050
- plh1: 43ohm

These values are without pch, sound ic and lan ic

Thank you!

[Dan115]

Re: Acer Nitro 5 3valwp short 1ohm

Hi Thomas,
Where are you with your laptop problems now? Did you get to some results since last post? Thanks

[Thomas8607]

Re: Acer Nitro 5 3valwp short 1ohm

Hi Thomas,
Where are you with your laptop problems now? Did you get to some results since last post? Thanks

Hi Dan
I haven't looked since then. I can't find any fault. I will try to load the 1.05 and 3.3v rails without pch.

[Dan115]

Re: Acer Nitro 5 3valwp short 1ohm

I have +3VALW , +3VALWP all shorted. PU301 is good but does not start up if PJ302 is cut off. PJ501 for +5VALW good. My PCH is done. How did you manage to solder the new one and not damage it? I have only hot air gun.

[Thomas8607]

Re: Acer Nitro 5 3valwp short 1ohm

I have +3VALW , +3VALWP all shorted. PU301 is good but does not start up if PJ302 is cut off. PJ501 for +5VALW good. My PCH is done. How did you manage to solder the new one and not damage it? I have only hot air gun.

I removed it with hot air. The new with reball device, not me.

[Dan115]

Re: Acer Nitro 5 3valwp short 1ohm

What do you mean with " the new with reball device " - is it BGA resolder station? Could you share the exact seller you bought the chip from( AliExpress I presume )? Thanks

[Thomas8607]

Re: Acer Nitro 5 3valwp short 1ohm

I have +3VALW , +3VALWP all shorted. PU301 is good but does not start up if PJ302 is cut off. PJ501 for +5VALW good. My PCH is done. How did you manage to solder the new one and not damage it? I have only hot air gun.

What do you mean with " the new with reball device " - is it BGA resolder station? Could you share the exact seller you bought the chip from( AliExpress I presume )? Thanks

Yes, with bga reball station.
I bought from aliexpress, https://a.aliexpress.com/_mONLHnY

[Thomas8607]

Hello.
I took out my motherboard again and installed another pch (new one from aliexpress, sumhs).
I took a picture and measured the resistors again. It is 5valw by default, when I press the power button the voltages 3.3valw, 1.8valw and 1.05valw appear, but after 15sec they turn off.
The power-on sequence is good until PM_SLP_S4, the s4 signal no longer changes to 3.3vra, it remains 0v.
I measure 1.05, 3.3 and 1.8v voltages on the capacitors on top of the pch. I don't measure anything on the pch 32.7khz crystal with an oscilloscope 🙁 The bios already wrote it, I don't know if its content is good

Thank you!

[Sephir0th]

This normally.means either bridged solder balls/bad PCH or BootGuard enabled. Bad luck i would say. Try to find a PCH without BootGuard being enabled

[Thomas8607]

This normally.means either bridged solder balls/bad PCH or BootGuard enabled. Bad luck i would say. Try to find a PCH without BootGuard being enabled

Does this mean that it's definitely a PCH replacement? This will be the third one.

[Sephir0th]

If you want definitive answers, then you have choosen the wrong job.
this is the reason why it's usually not really economical to perform such tasks. For me it looks like still something wrong with the PCH but am I a absolutely sure? Not really, since it requires to rule out all the other possibilities why SLP_S4# is not deasserted, a very detailed visual inspection and maybe to know more about the board history.

[Thomas8607]

If you want definitive answers, then you have choosen the wrong job.
this is the reason why it's usually not really economical to perform such tasks. For me it looks like still something wrong with the PCH but am I a absolutely sure? Not really, since it requires to rule out all the other possibilities why SLP_S4# is not deasserted, a very detailed visual inspection and maybe to know more about the board history.

The charge controller IC was missing, the sound IC, the lan IC and the PCH were shorted (at 3.3V, 1.8V and 1.05V). Removing these eliminated the shorting. All ICs were replaced from a donor motherboard (except the pch, from aliexpress). The PCH was not installed by me, it was done by someone who has experience with it.
The PCH RTC 32.768KHz quartz did not show anything with an oscilloscope.
I don't know what signals I need to check to proceed further.
Thank you for your help!

[Thomas8607]

After replacing the PCH, all voltages turn on and do not stop, except for VCC_CORE and VCC_GT
These remain at 0V.

I checked these signals:
VR_ON ok
VCC_SA 1.04V
VCC_IO 0.95V
+1.05V VCCST 1.042V
+1.05VS VCCSTG 1.044V
+1.2V_VCCPLL_OC 1.2V
PCH_PWOK 3.3V
SYS_PWOK 3.3V
PLT_RST# 3.3V
DRAM_RESET# 1.2V
Core vreg Alert 0V
VR_HOT# 1V
VR_PWRGD 3.3V