Computer Updates – 4/6/2018

It’s been a while since the last update. So, how have things been going?


So, the T420 is perhaps the biggest and most important project on my plate right now. My cousin has been working on the laptop for me as I didn’t really have the time or space to work on it after returning from Spring Break.

The news has been half-and-half; half good, half bad.

My cousin was able to get it past the “blinking power LED” phase. He acted like the machine was trying to boot and that it was POSTing. However, the bad news – no video. He mentioned that although the ThinkLight (a LED ThinkPads have near the above the screen to illuminate the keyboard) illuminated, there was no backlight or anything. When an external monitor was connected to the VGA port, nothing.

This isn’t good. It could be a variety of problems that would require further testing. The cable is tightly connected and appears to be in good shape, which may mean that another problem is causing it. It could be a bad graphics processor/video output circuitry, a bad lid sensor (see below), or some other things.

Unfortunately, this may require replacement of the entire system board. While not horribly expensive, it is going to be a hassle to find one which matches the FRU part and replacing the system board is more complicated as it requires total dis-assembly – including removing the magnesium frame. (This is why I like working on desktops a lot more!)

The interesting thing is that it is a learning process. I learned that instead of having a microswitch to detect the lid position, it likely uses a “hall effect” sensor. The hall effect sensor is used to detect a magnetic field. If a magnet is close enough and produces a strong field, the computer can determine if the lid is open or closed. (Which makes a lot of sense, especially in MacBooks and the like. I knew of the hall effect, but didn’t know the application within laptops.)

It’s currently a piece at a time. Fingers crossed the system board checks out.


Because the T420 has been down, the T42 has been my workhorse – well, sorta. It can’t do everything, so I end up actually using the school computer lab and the computer at my job to do some things.

However, the T42 has been able to do a lot. Since I upgraded to Pale Moon, I’ve been able to actually do some more things, such as write this post and be able to add pictures and formatting.

Unfortunately, there are some problems. Since the T42 is limited in memory, Pale Moon is still fairly unstable and even writing posts or opening a post in the editor can cause it to crash. I still can’t view PDFs, watch YouTube videos (or any video), or even answer e-mails.

I may purchase 2GB RAM to install into the T42, since I don’t know how long the T420 will be down for. My fingers are crossed that the T420 can be fixed (especially without having to replace the system board) as it is my main machine and is more capable.