View Full Version : What's wrong with my G750JH/780m? When the heat reaches 75c, the GPU goes haywire

06-21-2015, 03:46 PM

I have encountered this issue lateley. Every time I run something that uses the GPU, when the heat reaches 75c,
the GPU goes haywire, and causes the CPU to do the same as well, until laptop is restarted.

On my last test (one of several with same result) with Fumark, this is what I get:
The following test has been done like this:

Because the system becomes extremely non responsive, I have scheduled a 60 second delayed restart command with
- shutdown -r -f -t 60
- I made GPU-Z to output the data to a file
- and I ran Fumark

At fumark when the temperature reached 75-76c things went crazy (i.e. Sound lags, Mouse lags, everything lags), I let it stay until the shutdown timer expired and restarted the computer.

Is this throtteling issue?

p.s. G750JH

06-21-2015, 05:55 PM
Undust it and repaste and you'll be fine!

06-21-2015, 09:31 PM

I'm curious, what is your comment based on?

06-22-2015, 06:01 AM

I'm curious, what is your comment based on?

I owned several g series laptops. Stock thermal compound is not the best one it completely dries and become hard like a wall... Also after a some time of usage there is plenty of dust in it because of huge airflow. The first thing before panic is to clean everything and change dried thermal compound then test again.

06-22-2015, 01:21 PM
The reason why I'm sceptical about your answer is that the heat is not even reaching critical levels... My GPU can handle ~90c without problems... but this issue is new and it doesnt even pass 76c and it goes crazy...
Also, I usually clean my laptop from dust on monthly basis...
I wont be able to open my laptop until next weekend, until then I can only do "software" related solutions.

I tried:
- Fresh reinstall with DriverSweeper the GPU driver
- Tried multiple versions of the GPU driver... and even installed a version I used to use without problems...

I've also thought about reflashing the VBIOS but;
1. I didnt have a copy of the original from another laptop.
2. I've only done VBIOS flashing once and it was following an old undervolting guide. So, I didnt want to try this one yet. (Yeah, I'm aware of how to blind flash the VBIOS :))

p.s. This is not the first G series for me. I've had G53SX and several other laptops in my life and I've seen throttling before, but this one is unique.

06-22-2015, 01:55 PM
Temperature sensors can show wrong temp in different apps! When the thermal compound dries it cant effectively output heat to radiator so the chip is overheating and will throttle. You can flash bios or vbios but it will do anything.

06-26-2015, 05:36 PM
Just completed the disassembly's and the assembly of my laptop.
After a small stress test for the GPU, it was fine...

The old thermal paste was still not so "frozen", but I reapplied it with a non-metal thermal paste again and assembled the laptop.
Not sure if the new thermal paste or removing the bios battery fixed the issue, but either way the max temp is now 86c instead of 92-94c

Thanks for the replies :)

06-27-2015, 01:33 PM
Did this fix the problem? Have you tried re-installing a new driver? Because I've had this same exact issue somewhat, only limited to INGAME however and my fix was COMPLETELY removing NVidia driver through safemode and reinstalling it 100% fresh, then doing a kill on my powerswitch.

A temporary fix was going to Device Manager, finding your card, right clicking it and hitting DISABLE, then ENABLE 10 sec later.

You mentioned your CPU however so that makes me a little unsure if my fix applies to your situation. Try it out, return with feedback if your problem persists! :3

06-30-2015, 11:52 PM
Did this fix the problem?

That's what I kind of said

After a small stress test for the GPU, it was fine...

07-01-2015, 02:35 AM
Ohes, sorries. ;d