Monday, October 12, 2015

Loose hood lock on my old QX4

This post is definitely not about IT.

As almost everybody else in US I own a car. It's an old SUV - QX4. Being on visa does not let you to earn more to keep more, so I have to spend less to keep more :) And so I fix my own car.

Anyway, this particular model is known to have one common problem - loose front hood lock. In many forums you can find the problem described as "hood rattle". I've seen a lot of forum posts about this problem, but I never actually thought that I have this problem as well.

About a week ago I noticed that my hood...shakes. Nothing crazy, but it really did not feel like it was dead on where it was supposed to be. It was definitely a bit loose. And I bet that it was like that for all the previous year!

So after a very easy fix (undo 3 bolts, push the lock down as much as possible, level the lock, tighten the bolts) I took a car for a test drive and I was shocked. All the explainable rattle, muffled clanking on speed bumps and bunch of other symptoms are gone ! I was always blaming the suspension, mounts and any piece that has rubber in it, and all this time the problem was in a front hood lock.... Crazy!

Friday, October 9, 2015

Why does my PC refuse to fall asleep?

I have a Windows 8.1 machine, and it would not sleep no matter what.

The display would turn off, but it just never wanted to go into the Standby mode.

Long investigation revealed two issues:

  1. The common one - media streaming + the homegroup issue (this one is easy to google).
  2. My soundcard driver was keeping the PC awake using SetThreadExecutionState API.
If you are only looking for the first one, you can use powercfg.exe /requests, and look for any requests on the SYSTEM level. You can actually override such requests and if it is the only problem, then it will go away.

The other one can only be detected by running the powercfg.exe /energy command. It generates a report which includes information about everything that Windows knows about Just run that, read the report, read through everything in the Error section. Any problem related to preventing windows from sleeping has to be addressed. In my case I had to install a proper driver instead of a default one.

Btw, a side note on the first issue. In my cases tweaking media sharing settings or the homegroup settings did not actually help. The following this was still showing up in the report from powercfg /requests: "\FileSystem\srvnet"

At the end the solution was quite simple: stop and disable Homegroup Listener and Homegroup Provider services (I do not us the homegroup) and a service called "Windows Media Player Network Sharing Service". That was it, the request for staying awake was gone.

UPDATE: It has turned out that after the restart the sound card driver is still preventing my PC from sleeping. There are two applications that can be blamed for that: Steam and UPlay. Both have some well-known bugs that do not release the sound card resources, and that prevents the PC from entering the Sleep mode. So either have to close the apps, or press the sleep button manually. Eventually I will look into some brute force way of overriding this behavior - I would rather have my PC go to sleep when unattended than not go to sleep unless I remember to press the button...