G751JY Shutdown Issue (Circuit Problem) Where should i look?

[Zwaeaehn]

Hello community.

I'm from Germany and 30 years old.
(So ​​please don't scold me if my English isn't perfect.:D)
I have owned the G751 since 2015 and have always been satisfied so far.
But this one tiny thing is just really annoying!

It is a known problem with the G751 notebook and I have not yet found a solution on how to fix this problem.

In advance:
-It's not the battery (New battery is already installed but the issue is the same)
-It's not Windows
-It's not the bootloader or anything like that
-The problem is without a charger, not with the charger connected. (added 26.10.2020)
-It is the mainboard <<<<

I just know it's getting worse.
At first it was at 60% remaining capacity of the battery.
Then it was 70% and now at about 80% the laptop switches off.

The laptop only turns off when the load (CPU and or GPU) becomes too high.
(Apparently with a high battery load)
If i reduce the brightness and reduce the CPU performance to <50%, it will work until about 15-20% remaining battery capacity.
If I limit the CPU performance more than <50%, it works even up to 5% remaining battery capacity.

So, a function (or circuit) has to be installed somewhere that checks the voltage at which the battery should switch off the laptop.

I know that you don't need to ask Asus support, they have no idea either.
I'm an electrician and I'm trying to find the problem, but of course it's difficult without schematics.

My question is, has anyone looked into the circuitry yet?
Does anyone know where on the board the battery voltage is checked or know which component on the board is slowly dying?

Is it possible to reduce the (critical) tension in the bios?
Flashing Bios is not a problem, but I have to know which setting is responsible for it.
There must be a setting somewhere that says that the laptop should be switched off from a critical (voltage?) Limit.

I hope there are some electronics specialists here too. :eek:

[jdfrench3]

When I post questions to this forum, for user support, answers are expected, please answer my questions.

1. Do you have the capability to "load test the battery"? Here in US we have places where the battery can be tested using a load tester, to check for bad cells. Over the years about 30% of new batteries I have purchased over the Internet are bad upon receipt and I have to get another.

2. How is your charging brick? Does the voltage match that listed on the back of the brick? Again the charging brick can be tested at the local shop (voltage and current).

3. If the charging brick is attached you DO NOT have these problems?

4. What does this following sentence mean? "The original had the same issue. (~70-80%)"

[Zwaeaehn]

jdfrench3 wrote:

1. Do you have the capability to "load test the battery"? Here in US we have places where the battery can be tested using a load tester, to check for bad cells. Over the years about 30% of new batteries I have purchased over the Internet are bad upon receipt and I have to get another.

I have measuring tools (multimeter, ammeter, etc.) but I don't have a pinout from the battery yet.

jdfrench3 wrote:

2. How is your charging brick? Does the voltage match that listed on the back of the brick? Again the charging brick can be tested at the local shop (voltage and current).

Yes, the voltage is stable and the lines/connection of the powerboard have a good resistance (<0,X ohms)

jdfrench3 wrote:

3. If the charging brick is attached you DO NOT have these problems?

Correct. No Problems then.

jdfrench3 wrote:

4. What does this following sentence mean? "The original had the same issue. (~70-80%)"

I had the same shutdown issue with the original battery.
Changing the battery didn't solve the problem.
I have 2 new spare batteries here.
Both new batteries have the same problem so it's not a battery problem.

[Sanctrum]

Zwaeaehn wrote:
You should first read my article properly before you start saying nonsense.

I wrote:


And before you accuse someone of being a troll, educate yourself and read the definition of "troll".:rolleyes:

I am not a technical layman and I will describe my problem as precisely as possible.
So I expect an explanation when making claims.
Especially when you talk about other things that probably have nothing to do with it.

You wrote:


But it's like i said, it's not a connection problem.
This is not the first time i've opened my laptop.
The connector is firm and the solder ist ok. -> I've checked all solder points with a multimeter.
A loose connection is also excluded and the cables are also okay.

Almost all topics with the random shutdown describe a completely different problem picture.
If it's that simple I wouldn't ask ...

You do not understand too. Maybe the language problems....
The problem is not with the solder joints itself... I belive the problem is INSIDE the power connector jack... It's mechanical problem. Even if you will resolder the same connector jack - you will still have the problem even with the new soldering.

You have to replace the connection jack itself. Or entire micro DC-in board wit the new connector jack...
https://www.youtube.com/watch?v=tRYdzqDJ3KY

[Zwaeaehn]

Sanctrum wrote:
You do not understand too. Maybe the language problems....
The problem is not with the solder joints itself... I belive the problem is INSIDE the power connector jack... It's mechanical problem. Even if you will resolder the same connector jack - you will still have the problem even with the new soldering.

You have to replace the connection jack itself. Or entire micro DC-in board wit the new connector jack...
https://www.youtube.com/watch?v=tRYdzqDJ3KY

If it were really the connector, how do you explain that it works with 100% battery charge and the problems only occur from 70-80%? :confused:

[Sanctrum]

Zwaeaehn wrote:
If it were really the connector, how do you explain that it works with 100% battery charge and the problems only occur from 70-80%? :confused:

Simple if true for your case - but it was true for mine case and replacing DC-in power jack revived my gaming:
1. G715JY while gaming takes power from BOTH: the battery and the PSU. G751JY is not designed for gaming with 100% capacity... without proper tandem of PSU and the battery.
2. If PSU connector is defective more power is taken from the battery than expected. Often you can even feel the heat at the connector and at the battery. If connector is not ok then during heavy gaming you can see that battery % drops over time! What is NOT normal. The properly functioning G715JY is holding the battery charge level between 95% - 99% during several hours of uninterrupted heavy gaming! Proper connector must be cold.
3. If more power is taken from the battery, since due to bad connector PSU can't provide required amount of power to laptop and to battery - so the battery overheats as is discharging too fast - since CPU/GPU still require high power! Fast discharging makes more heat then normal charging.
4. If the battery overheats - it jumps into the safe mode since it also has built in thermometer - not allowing to charge it again until cool down... and sometimes even forcing the laptop to shutdown! Since both, charging and discharging make the battery hotter. This is the safety measure not to set fire of your battery->laptop->house.
5. So your laptop GPU/CPU clocks drop down due to battery safety signal - since the battery is no longer capable to provide expected power as is too hot - and you can even see at column N that it also impacts the charging power - what is actually expected since safety is also built in into charging - hotter battery = slower charging... up to complete charging blockade. And it has nothing to do with CPU/GPU temperatures. Battery does not have any cooler and do not overheat from CPU/GPU heat... but does so due to too much workload... Only stop using / disconnecting the battery actually cools it down over time.

So your MB is defective or your battery is defective or the DC-in jack is defective... And all you can do about it (as the cheapest option) is to replace the DC-in jack first. Since you already replaced the battery as stated in the opening post... AOT for me.

[Zwaeaehn]

Hi

thanks for your explanation.
It would all make sense, but I didn't even connect the power supply.
I don't even know why column "N" shows such values at all, although the battery is not being charged.:confused:

Edit: Maybe the header text of the column "N" is miunderstood.

Maybe it means, it has a discharge rate of x,xx W.
That would make sense.

Therefore i think it is a mainbord problem.
Do you have a schematic of the pinout from the battery?

Perhaps the temperature of the battery in the mainboard is not measured correctly?

But i honestly believe it's the voltage or capacitance measurement.

Because normally, when the performance becomes critical (<1%) and you don't shut down Windows, the laptop just shuts down.

What if the mainboard does not process these values correctly and thinks at 70% that the battery is 0% charged and therefore shuts down?


This problem has bugged me for ages but I don't want to give up until I have a solution.

[Sanctrum]

Zwaeaehn wrote:
Hi

thanks for your explanation.
It would all make sense, but I didn't even connect the power supply.
I don't even know why column "N" shows such values at all, although the battery is not being charged.:confused:

Edit: Maybe the header text of the column "N" is miunderstood.

Maybe it means, it has a discharge rate of x,xx W.
That would make sense.

Therefore i think it is a mainbord problem.
Do you have a schematic of the pinout from the battery?

Perhaps the temperature of the battery in the mainboard is not measured correctly?

But i honestly believe it's the voltage or capacitance measurement.

Because normally, when the performance becomes critical (<1%) and you don't shut down Windows, the laptop just shuts down.

What if the mainboard does not process these values correctly and thinks at 70% that the battery is 0% charged and therefore shuts down?


This problem has bugged me for ages but I don't want to give up until I have a solution.

Sorry, but I do not have answers for your questions. AOT for me. All I could help I have already written like jdfrench3 done too. You should listen... not argue. If your DC-in jack connector is warmer than your hand so it is 100% defective and you MUST replace it. If your battery lower charge % during heavy gaming means again then DC-in jack is defective and you must replace it. Or you put at risk your home/battery to set on fire. Nothing more to be said. If you even do not connect PSU - it's you to blame all this. As I said - you are NOT listening and you are changing your statements.

[Zwaeaehn]

Sanctrum wrote:
you are NOT listening and you are changing your statements.

No, YOU are not listening...:rolleyes:
Read everything a little more slowly.
Please do not think that I am stupid and have no idea about electrics.
If I tell you it's not the connector, please believe me.

The plug is neither hot nor loose. JUST LISTEN TO ME instead of insisting on your pride in solving my false suspicion problem.


Many people may have had a similar problem, but this is something completely different.
I know that you want to help me and I thank you for that, but you have to listen to others too. 😉

Maybe it was my mistake because I didn't explicitly write that I have the problem without a charger, but in post #10, you should have noticed that I had the problem without a charger.

See:

"(Because meanwhile gaming is impossible without charger.)"

I'll add the following line to my first post:
The problem is without a charger, not with the charger connected.

Maybe we can just start over from zero.


Btw, when I find the problem at some point, I will report on it.