Acer A515-52 LA-G521P EH5AW

[mcplslg123]

Re: Acer A515-52 LA-G521P EH5AW

PQZ1 shot 19v straight to the cpu and killed it, you are milking a dead cow, don't waste time anymore.

That was the case with original OP and not @vannix.

[mcplslg123]

Re: Acer A515-52 LA-G521P EH5AW

KB9022 will not get programmed from main bios as ec is not blank. Updating the formware from windows will update ec firmware as well which is not possible here. So you need to flash kbc separately.

[vannix]

Re: Acer A515-52 LA-G521P EH5AW

See attached -> measure the voltage at the referenced checkpoints. Post the readings.

1=3=4=19,65v
2=24,02v

Sounds good but do also check the resistance to ground of the VCC_CORE rail. Remove all power -> meter in resistance mode -> post the reading to confirm the CPU is still ok.

NAME / USE FOR / OHM TO GND / VOLTAGE

PL401 / +5ALWP / >500K / 5,236V
PL402 / +3ALWP / >500K / 3,332V
PL502 / +1,2VP / >500K / 1,211V
PLZ1 / +VCC_CORE / 3,2 / 0,6 to 1V
PLZ2 / +VCC_CORE / 3,2 / 0,6 to 1V
PLG1 / +VCC_GT / 5,6 / 0,0 to 0,4V
PL1002 / +1,35VSDGPUP / 602 / 1,361V
PL1202 / +VGACORE / 8,4 / 0,906V
PL1203 / +VGACORE / 8,4 / 0,906V

with the ram inserted in the slot furthest from the cpu this morning i noticed that for a moment it showed the acer logo before becoming like in the attached video

with the ram near the cpu the +VCC_CORE and +VCC_GT are 0,000v and it shutdown after 3 seconds, then on again, then off....... this for 10 times. then it stay off.

without ram it stay on with same voltage except for:
PLG1 / +VCC_GT -> stable to 0,021v
PLZ1-PLZ2 / +VCC_CORE -> stable to 0,858v

KB9022 will not get programmed from main bios as ec is not blank. Updating the formware from windows will update ec firmware as well which is not possible here. So you need to flash kbc separately.

since this morning the pc started up for a moment i didn't reprogram the EC yet, because i think the problem is with the cpu or some bad soldering near it



can @DrFalken confirm the PLG1 / +VCC_GT voltage with the board powered on?

[DrFalken]

Re: Acer A515-52 LA-G521P EH5AW

1=3=4=19,65v
2=24,02v



NAME / USE FOR / OHM TO GND / VOLTAGE

PL401 / +5ALWP / >500K / 5,236V
PL402 / +3ALWP / >500K / 3,332V
PL502 / +1,2VP / >500K / 1,211V
PLZ1 / +VCC_CORE / 3,2 / 0,6 to 1V
PLZ2 / +VCC_CORE / 3,2 / 0,6 to 1V
PLG1 / +VCC_GT / 5,6 / 0,0 to 0,4V
PL1002 / +1,35VSDGPUP / 602 / 1,361V
PL1202 / +VGACORE / 8,4 / 0,906V
PL1203 / +VGACORE / 8,4 / 0,906V

with the ram inserted in the slot furthest from the cpu this morning i noticed that for a moment it showed the acer logo before becoming like in the attached video

with the ram near the cpu the +VCC_CORE and +VCC_GT are 0,000v and it shutdown after 3 seconds, then on again, then off....... this for 10 times. then it stay off.

without ram it stay on with same voltage except for:
PLG1 / +VCC_GT -> stable to 0,021v
PLZ1-PLZ2 / +VCC_CORE -> stable to 0,858v





since this morning the pc started up for a moment i didn't reprogram the EC yet, because i think the problem is with the cpu or some bad soldering near it



can @DrFalken confirm the PLG1 / +VCC_GT voltage with the board powered on?

Board powered.

PLG1 to GND:
- 5 Ohm
- 0 V

[vannix]

Re: Acer A515-52 LA-G521P EH5AW

Thank you for your measurement, however is difficult to understand how much vccgt must be for this board, even reading on the web there is not enough information. I'll do other tests these days, if in the meantime there are other suggestions they are welcome

[DanielDacko]

Re: Acer A515-52 LA-G521P EH5AW

That was the case with original OP and not @vannix.

Sorry, didn't saw that. Well, that happens when people hijack someone's else thread, instead of opening new one.

[mcplslg123]

Re: Acer A515-52 LA-G521P EH5AW

Yes, It happens sometimes with all of us.

[mcplslg123]

Re: Acer A515-52 LA-G521P EH5AW

Thank you for your measurement, however is difficult to understand how much vccgt must be for this board, even reading on the web there is not enough information. I'll do other tests these days, if in the meantime there are other suggestions they are welcome

You cant measure VCCGT with simple DMM on newer boards. There may be a slight deflection on your DMM while turning on but wont show any readings. You need a scope to check that. If you are sure about the resistance on VCC_GT, then remove the coil and inject 0.7V-0.8V on the consuming side(The side which goes to cpu) and see if there is display.

[vannix]

Re: Acer A515-52 LA-G521P EH5AW

Sorry, didn't saw that. Well, that happens when people hijack someone's else thread, instead of opening new one.

[Small OT]
I don't think this is a thread hijack as the problem is very similar if not the same. Do you think it is better to open a new thread for the same pc, the same board and probably the same problem?
I think it is useful for users who will search on this forum or on google to have a unique reference for similar problems and that have a boot behavior the same as mine and DrFalken's.
This obviously doesn't mean that the thread has to become 50 pages long and be written for years for totally different problems.
I personally hate wasting so much time reading various threads that have similar symptoms and always the same ending.
Anyway i say thank you for the observation you made, because this was my personal opinion and it can be wrong.
[End OT]

You cant measure VCCGT with simple DMM on newer boards. There may be a slight deflection on your DMM while turning on but wont show any readings. You need a scope to check that. If you are sure about the resistance on VCC_GT, then remove the coil and inject 0.7V-0.8V on the consuming side(The side which goes to cpu) and see if there is display.

You are right, using even a small chinese oscilloscope i can read a fast voltage ranging from 0 to about 1.2v and then it drops to about 0.4v after a few seconds. The schematic shows "0-1.52v / 31A" so i can assume that it's correct.
I have made these measurements when the pc is started and it shows the artifacts on the screen (it rarely happens that it starts up). I noticed that after about 1 minute the cpu is not very hot (about 65 degrees with heatsink without fan) but PLZ1 and PLZ2 are about 95 degrees. Cpu core probably draws too much current?


EDIT: the consumption from the power supply is very high, using a bench power supply it absorbs about 2 amps with only the lcd display connected and a ram module.
With cpu at about 60C i have 0,8ohm between +VCC_CORE and GND.
When cpu reaches 70C the board draw about 3,3 amps and the 2 coils are more than 100C. +VCC_CORE to GND is 0,3ohm. The cpu is dead....
It's a shame because it's an 8th gen i7, but with newer acer notebooks i'm not lucky.
Thanks to all for the help, i will offer the customer a new or a refurbished board.