Category Archives: Fixed problems

[Solved]Get back Grub in Windows 8.1

I was using grub to dual boot my Lenovo Y410P with Windows 8 and Ubuntu 14.04.

Recently I finally decided to upgrade my Windows 8 to Windows 8.1 considering it should be pretty stable by now. However, to my horror(or rather not surprisingly), my default bootloader has been changed to Windows Bootloader which means I could not access my Ubuntu 14.04.

Usually this takes a while to fix, involving repairing grub/BCD and tend to be tedious. However, I managed to found a much simpler and direct solution to this.

With the new UEFI specification, we can actually choose the default boot manager instead of replacing one with another. All it takes is to go to UEFI Firmware settings and change the order of boot managers. Which means grub and Windows boot manager can co-exist somewhere in the hard disk and we can choose which one to use in the BIOS UEFI settings.

Accessing UEFI settings in Windows 8.1 is a bit different from what happens in Windows 8, you can follow these links:

http://www.thewindowsclub.com/access-uefi-firmware-settings-windows-8-1

http://acer-au.custhelp.com/app/answers/detail/a_id/32048/~/accessing-uefi-in-windows-8.1

The menu is something like this:

UEFI Settings

UEFI Settings

One you are in the UEFI boot priority settings, you can simply change the position of Ubuntu to the top so that grub will load when the PC is turned on:

UEFI Boot order priority setting

UEFI Boot order priority setting

(All photos taken by me)

 

 

[Solved]Lag issue with meteor and stuck at loading

Meteor is the web framework that I have been learning for past few weeks. It is powerful and easy to learn but some functions are still under-developed hence some bugs.

When playing with the Todo List example, I discovered a bug in the example. The example has a function to display a “loading text” in item panel when the user selects a new list and the corresponding items are being loaded from database. However, if the user switches between the lists very fast and selects the next list before the current list is loaded, the item panel will be forever stuck at loading. This may not be a issue when running on a local server but it would be much more serious if the Internet connection to server is slow.

I am not entirely sure of the cause of this problem but it has to do with how DOM elements are updated when the variables get changed. For some reason, if the Meteor.subscribe() method does not return before the next execution, the DOM elements will not be updated.

I solved this issue by using a session variable, which is altered when new list is selected. In this way, a selection of new list will always trigger the change in session variable and hence update DOM accordingly. Below is the relevant code modified by me:

This technique is related to meteor’s reactivity, here is the reference on Reactivity for meteor.

[Solved]Ubuntu 13.04 Blankscreen on boot problem

Today I booted to my Ubuntu but it welcomed me with a blank screen without any light from the screen.

I thought it is the normal brightness and back-light problem so I tried to turn up brightness level from keyboard but nothing happened.

Then when I tried to adjust volume using keyboard, I was surprised(or rather not surprised) to hear the usual sound effect from Ubuntu system. So I was assured that the system has been booted properly and the only problem is that the screen did not show up.

Intuitively, I thought of the possibility that the screen is actually “turned off” the same way as the brightness was set to zero on boot. With that I tried to press the keyboard combination to “turn on” the screen, which is “Fn+F2” (for my Lenovo Y410P).

And yes, I got back my Ubuntu desktop. Pressing the keys again will give me blank screen again(as expected since it is indeed designed to work).

No idea why the screen was initially turned off though.

Solved issue with vglnk (all websites having a script related to vglink attached to the end)

So today I was trying to pick up node.js. So I run through the first tutorial for displaying hello word.

To my horror, the simple website seems to different than what I expect. I looked at the console where I see something related to a website called viglink.

vglnk

vglnk2

It appears that some code (vglnk) related to this site viglink is “attached to” the end of my webpage. Apparently I did not do this so I suspected this is due to node.js.

However, when I opened up other websites and looked at the Chrome console again, I saw that script appearing again:

vglnk3

This was kind of scary to think about, the fact that every webpage I visit is attached with some script that comes from nowhere.

I was thinking of browser hijacking but I could not find anything on Internet that says viglink is hijacking the web browser.

Just when I was about to give up, the Chrome console gave me an important clue:

vglnk4

So it appears that something else is behind this script and actually calling the script, I clicked on the links.js.

Here I found out the codes that attached the scripts to the end of each webpage:

vglnk5

Following the description above the code, I guessed that it is the Chrome plugin – Unblock Youku that is creating all of this.

And it turns out that indeed that was the case.

The origin of this viglink issue is written here by the author of Unblock Youku:

https://github.com/zhuzhuor/Unblock-Youku/wiki/Support-Us

https://github.com/zhuzhuor/Unblock-Youku/issues/47

The truth is,  the author of this plugin wants to get some profit from the plugin. If you choose to support the plugin, you will experience the issue mentioned above.

I also found out that the author has given information about this VigLink when user clicks the extension icon and sees the option to support the plugin:

vglnk6

However, this information was not there when I installed the plugin and clicked on the support button. Now as I think back, I went through much trouble only because this information was missing. The author should have added this notice when implementing the “support option”.

Actually, I would not have noticed this added information if I did not click on the extension icon again to try disabling it. (This is really no reason for clicking on an extension icon when I know that it works automatically, especially after I have already clicked on it once)