Fans run full blast while SHUTOFF!?

[CrowMagnuS]

If I turn my laptop off (zbook, windows 10) the wifi and mute buttons stay illuminated and the fans kick on full blast. I noticed if I unplug the cable and battery, it automatically boots when either are inserted... I've updated bios, checked drivers and power options for buttons, still lost

 

[marksavio]

that is a common sign that your laptop is experiencing overheating issues.
* clean the laptop of dust/hair in your fans, airways, and heatsinks
* reinstall latest laptop drivers from the support site. start with your chipset. then your graphics. then may be the others. BIOS may be necessary.
* shutdown your laptop. remove ac adapter/battery. press power button for 1min.
* only use your laptop on a dry solid flat surface.

 

[CrowMagnuS]

that is a common sign that your laptop is experiencing overheating issues.
* clean the laptop of dust/hair in your fans, airways, and heatsinks
* reinstall latest laptop drivers from the support site. start with your chipset. then your graphics. then may be the others. BIOS may be necessary.
* shutdown your laptop. remove ac adapter/battery. press power button for 1min.
* only use your laptop on a dry solid flat surface.

I obsessively clean both laptops and desktop with a datavac on an anti-static table. CPU-Z says I haven't reached over 48c in temps, and 60c for GPU. Manually with through all drivers, and updated bios. It's almost like CMOS battery is out but never get the usual cmos reset warning. But it started on my ZBook and Envy on the same day. I'm assuming windows update but rolling back did nothing.

 

[marksavio]

you may want to double-check your fans in that laptop. if they are irreplaceable, you might want to consider buying a new one.
you can try the extreme by dong a fresh windows install first before considering hardware issues. since you have already done a BIOS update and CMOS clear.

 

[CrowMagnuS]

you may want to double-check your fans in that laptop. if they are irreplaceable, you might want to consider buying a new one.
you can try the extreme by dong a fresh windows install first before considering hardware issues. since you have already done a BIOS update and CMOS clear.

I'll give that a shot. While operating it runs as expected. Shutting down, they kick on 100% and never stop until I hit the power and put it to sleep.

 

[InvalidError]

Sounds like the laptop's system power management chip isn't shutting down the fan power rail so the fans go full-speed when the laptop shuts down and their PWM control gets stuck at 100% from the control circuit shutting down. You can run in a similar problem on a PC if an externally powered accessory back-feeds power over the USB cable which keeps the PSU_ON pin asserted and prevents the PSU from shutting down even though everything else has stopped. If you have self-powered devices connected to USB ports, you may want to try disconnecting them to see if you may be running into a similar issue.

 

[CrowMagnuS]

Sounds like the laptop's system power management chip isn't shutting down the fan power rail so the fans go full-speed when the laptop shuts down and their PWM control gets stuck at 100% from the control circuit shutting down. You can run in a similar problem on a PC if an externally powered accessory back-feeds power over the USB cable which keeps the PSU_ON pin asserted and prevents the PSU from shutting down even though everything else has stopped. If you have self-powered devices connected to USB ports, you may want to try disconnecting them to see if you may be running into a similar issue.

Do you think this would be a replaceable part? Or is this catastrophic hardware failure?

 

[InvalidError]

Do you think this would be a replaceable part? Or is this catastrophic hardware failure?

It works as intended while the PC is turned on, so it clearly isn't a "catastrophic failure" where it would be completely uncontrollable. Repair-wise, it could be something as trivial as a bad solder joint on the motherboard, a missing pull-up/down resistor on the FET that should be gating power to the fan(s) while the control IC is shut down or something else of a similar nature. If there is a bad part on the board involved, it will most likely be a surface-mount job and could be difficult to figure out without board schematics.

If you aren't handy with SMD rework, the easiest (and possibly only) fix may be a motherboard swap.