Thursday, December 2, 2021

Fix - Mouse Scroll Wheel stops working

My mouse scroll wheel has been stopping working intermittently for a while. I decided to open it up to see if I could get it working again. I suspected that the mouse has an optical movement detection system for the scroll wheel (as for the mouse itself) because the wheel action is so light it can only be rotating on a shaft, and that dirt might be preventing the detector form working.

Removing the battery revealed a catch which when moved over with a screw driver allowed the top panel of the mouse (the flexible bifurcated ends of which flex to activate the mouse buttons) to be removed.

The scroll wheel (remarkably car wheel like) has spokes. I am guessing* that at the bottom a beam of IR light (because there is no visible light) passes through the spokes to a detector on the other side, and the interruption of the beam is used to detect motion of the mouse wheel.

The wheel was indeed quite dirty, and I noticed a foreign object, a thin strand of unidentifiable material at the side of the wheel which could indeed have blocked light from passing through the spokes of the wheel. An examination of the spokes with a magnifying glass showed they were dusty.

I gave the wheel a clean with a soft artist's paint brush, including the spokes, a wipe with an alcohol impregnated lens cloth and a blast with an air cleaner, through the spokes and underneath and to the sides.

The scroll wheel is now functioning normally.

So don't bin that mouse when the scroll wheel stops working - give it a clean!

* I was right:, has the details, including how the detector knows which direction the wheel is turning.


Tuesday, November 16, 2021

Error updating Debian Testing

I got the following error messages while updating Debian Testing this morning:

E: initramfs-tools: installed initramfs-tools package post-installation script subprocess returned error exit status 1

gzip: stdout: No space left on device
E: mkinitramfs failure gzip 1
update-initramfs: failed for /boot/initrd.img-5.14.0-4-amd64 with 1.
dpkg: error processing package initramfs-tools (--configure):
 installed initramfs-tools package post-installation script subprocess returned error exit status 1
Errors were encountered while processing:

Say What? This is a 500G HD and it's only 7% full!

Turns out /boot is on its own 500MB partition and its full.

I had too many old kernels installed, and the solution was to get rid of most of them (keeping one known good backup kernel).

I searched for "linux-image" in Synaptic, but this can be done from a command line too obviously.

When I had finished I ran

# update-initramfs -u

Which is the part of the update precess that had failed.

I will have to pay more attention to housekeeping from now on.

Sunday, October 24, 2021

Systemd messages after suspend in Debian Testing

I've been seeing some Systemd messages after this laptop comes out of suspend - but they only appear for a fraction of a second. I tried filming the screen as the laptop came out of suspend but only managed to get a blurry still by freezing the video.

How to read the error messages? I found I could read Systemd messages in real time, suspend and wake up the laptop and see the messages in the output. 

The command is

# journalctl -f

And the error messages were

Oct 24 19:21:38 Toshiba-laptop kernel: debugfs: File 'radeon_ring_gfx' in directory '0' already present! 

Oct 24 19:21:38 Toshiba-laptop kernel: debugfs: File 'radeon_ring_cp1' in directory '0' already present! 

Oct 24 19:21:38 Toshiba-laptop kernel: debugfs: File 'radeon_ring_cp2' in directory '0' already present! 

Oct 24 19:21:38 Toshiba-laptop kernel: debugfs: File 'radeon_ring_dma1' in directory '0' already present! 

Oct 24 19:21:38 Toshiba-laptop kernel: debugfs: File 'radeon_ring_dma2' in directory '0' already present! 

Seems to be a kernel bug (Arch Linux Forums).

Saturday, October 23, 2021

Gnome music is irredeemably ...

Update: I have discovered that music appears after a reboot. I haven't found a "search/refresh library" option in Gnome Music. Does it exist? IMHO it probably needs one.

5 years ago:

Gnome Music doesn't find any titles in my music collection - again...


Image source


Currently listening to:

From my music folder. On Gnome. Which I like.

Gotta agree with tiberiousr from reddit (link at top) on this one: "...shit".

Wednesday, October 6, 2021

XFCE and Gnome memory usage compared

In a previous post I asked how much memory my laptop needed, and found the answer was more than ii had, so I added some

At the time I was using XFCE, but now the same laptop is running Gnome 3, so decided to compare memory usage.

XFCE used 912MB of memory when it had loaded (converted from 870MiB in the screenshot below).

Gnome uses 1.3GB when it has loaded.

With Firefox open, XFCE used 2.68GB (converted from GiB).
Gnome used 2.3GB with Firefox open.

In both cases, there were multiple active tabs open, although different web sites with different content. I didn't attempt to use the same web sites, and I am assuming that the different memory usage by Firefox was down to the different websites open in tabs at the time. Memory usage by browsers does vary wildly according to the number of tabs open and the content of those tabs.

On a computer with limited memory, XFCE can be a good option, although the memory saved can be eaten up quickly by modern web pages with their scripts, videos and images.

Both XFCE and Gnome are perfectly usable on this very low spec computer (with XFCE having a slight edge in snappiness on occasion), but adding the extra 4GB of memory has made both much more usable with a modern bowser with a dozen or more tabs open.

Tuesday, October 5, 2021

Evolution Calendar - Syncing and adding reminders

Adding events to the Evolution calendar is intuitive, so I won't go into details: click on a day, add a time and a description and the basic event entry is done.

After that I had a couple of issues that took me some time to work out.

The first was that as Gnome is integrated with my Google account, I expected the event to appear in my Android phone's calendar, but it didn't. I couldn't work out how to sync the evolution calendar with my Google account.

The answer is to select the Google calendar as the default calendar, because the local calendar (On This Computer) is set as the default.

Select your Google calendar account, right click and select Properties, then tick Mark as default calendar.

The next issue was setting reminders. As I usually forget upcoming events, I like to get plenty of reminders from my computer and phone, so I clicked on the Reminders tab and selected 15 minutes before from the drop down menu.

Gnome applications are usually intuitive to use, but I have to say this window was not. There are to my mind several problems that actually make it counter intuitive.

First of all is the infinitive in Pop up and alert: The infinitive in computer GUIs usually presents an opportunity to give a command: Play, Pause, Stop, for example. Yes, I want to Pop up and alert, what do I do about it? I expected an OK or Confirm option here. I think Alert 15 minutes before the start, or Alert set for 15 minutes before the start would be clearer. Maybe it's just me.

The second problem I had was that I like to set more than one reminder, and the Add button was greyed out. It wasn't just me here as someone else had the same problem. I wrote "was" because Evolution was updated overnight and the Add button is no longer greyed out, as you will see in the screenshot above: it sets the Custom option, which allows more than one reminder. The solution if you have a version of Evolution with the greyed out button is to choose Custom from the drop down list.


Monday, October 4, 2021

How to pixelate text in the Gimp

There are times when I want to post a screenshot, but need to obscure personal information, as in the screenshot above from my previous post. Pixelating the text is a good solution because it can make the text unreadable whilst still leaving an impression of the text. I did this some time before for a previous post, and needed to do it again today for another post, but had forgotten how to do it. This time I am going to write a quick tutorial to remind me how to do it next time, and to help anybody who might want to do the same thing.

First, open the image in the Gimp:

Then select the text you want to pixelate with the Rectangle Select Tool:

Next, cut the selection:

And paste as a new layer:

Go to Filters > Blur > Pixelise and reduce the size of your pixel blocks until the text is unreadable but still gives the impression of text. Be careful that it is not possible to still read the text if you squint - in this image I need to go one step further:

When you are happy that the text is unreadable, go to Image  > Flatten image:

And here is the final result: