07-06-2016 10:09 PM
I have a Z710, on which the warranty expired about a month ago... Several days ago the fan started acting up. It randomly turns up to full speed (seems truly 100%, never heard it this loud previously), either through slow ramp-up or immediate. It will stay at full speed for a seemingly random period of time, after which it will progress to ~2seconds off, ~1second full speed. Once it has progressed to 2s-off/1s-on, it will continue that indefinitely until I unplug and pull the battery. If I simply reboot or shut down, the fan will immediately return to whatever state it was in before shutting down (either constant or intermittent 100%). Power must be lost entirely to "reset" the fan. This occurs while in the BIOS as well, which I guess makes sense, since from what I have found there is no control over the fan in this laptop beyond inaccessible BIOS parameters?
The CPU temp is usually sitting around 40C. If I heat it up by say, running Prime95, the CPU temps will climb and eventually stabilize at about 80C. The fan will slow down by the time it hits 60C or so, seemingly resuming its proper temp/speed relationship. But, if I end the PRIME95 test, the fan will resume its on/off cycle as soon as the CPU cools back down. Even while running PRIME95 at a stable 80C, the fan is not nearly as loud as it is during its 1s-on cycle or constant full-speed run.
So, in order to quiet down my laptop I can A) run a stress test (bye-bye battery life), or B) pull battery. Pulling the battery has unpredictable results. It seems to be the only way to make the fan stop going haywire, but after pulling the battery then powering back on, the dis-regulation could return anytime; could be 3 minutes, could be all day. I have not yet been able to figure out something that precipitates the fan runaway--it seems to be random.
I have pulled the back off and cleaned dust--there really wasn't any and it made no difference.
Does anyone have ANY suggestions? Flash to old BIOS (can't find one?). Way to mechanically hack the fan? The laptop is infuriating to use when I have to keep either pulling the battery or listening to the fan cycle full-speed every 3 seconds.
07-06-2016 11:03 PM
If the tempurature of the computer is rising dispite the ramping of the fans I would certainly not look into a way to lower the speed of the fan. It could be that there is software on the system which is causing the cpu usage to spike momentarily and then causing this reaction, or it could simply be an issue with the fan itself. Have you taken a look at the cpu utilization when this is happening to see if there is anything standing out in the task manager?
07-07-2016 05:42 AM
07-07-2016 02:34 PM
Sys3175, the fan is not responding to CPU use. As noted, it actually slows down and resumes proper regulation once I peg the CPU to 100%. While it's doing its full-speed run or 1s-on/2s-off cycle, CPU usage is typically in the 2-5% range, and CPU temperature is around 40C. It seems that it is only in the range of ~40-55C where something has gone unpredictably wonky with the regulation. Once the temp has risen, it seems the BIOS remembers the proper temp/speed curves.
Tripplec, I was not running the laptop without the battery. I meant only that in order to temporarily eliminate the fan issues, I had to shut it down, unplug it, and pull the battery. I would then reinstall the battery before starting it back up.
07-07-2016 06:42 PM
08-01-2016 08:11 AM
Similar thing happened to me. Laptop was running while in a carrying case for half an hour. No ventilation. When I turned it on later, the fan would cycle on and off over a 3 or 4 second period. This seemed to be the new off position for the fan, as it would work normally when the processor started heating up enough to require the fan. A bit of googling suggested this was a dust removal setting (makes sense it would turn on when laptop had no ventilation). But couldn't figure out how to turn it off, fan in a z710 is not user controllable.
Thank you for mentioning pulling the battery, I had not tried that. My fan is now running properly. I wonder if your fan is clogged with dust which is causing this setting to re-activate again for you after you reset it by pulling battery.
08-01-2016 08:20 AM
Interesting about the dust removal mode, I had not heard of that. But, cleaning out the dust (there wasn't much) was the first thing I did, and it made no difference.
It seems, for the moment, that the problem has mysteriously disapeared; the fan has not gone into ramp-up or cycle mode in almost two weeks now. Fingers crossed the gremlims are gone...