How to easily repair consumer electronics

Written by Asger Bjørn Jørgensen, 2017-06-06

Failure of low price consumer electronics, such as monitors, PCs, audio amplifiers, is often caused due to cheap electrolytic capacitors. They might cause failure as early as within only 3 to 7 years of purchase. The electrolytic capacitor is part of the power supply unit in many of these electronic devices and ensures stable DC voltage levels of for instance 12 V or 3.3 V inside the device.

Electrolytic capacitors are cheap and have a high capacitance to volume ratio, compared with other types of capacitors, making them advantageous for compact electronic devices in your household. However, the cheap electrolytic capacitors are filled with a liquid, which evaporates over time. This slowly increases the equivalent series resistance of the capacitor, leading to higher losses and eventually overheating of the capacitor. When this happens the pressure inside the capacitor increases, until the top "pops" off, evaporating the remaining liquid and causes the capacitor to fail. This "pop" of the top, ensures that the capacitor does not explode.

However, if the capacitor is the cause of failure, and did harm the rest of the power supply, it is easy to fix by just replacing these capacitors. I've done this with an old Hanns-G monitor. Whenever i tried to start it, the "power LED" would flash for a second, and then the monitor would go off again.

I popped off the plastic framing on the backside, and found a metal casing with two PCBs. One with the power supply unit and another with the video card doing all the processing, as shown in Fig. 1.

Fig. 1: Metal enclosure on the back holds both power supply and video PCB boards.


Disassembling the two boards i located the power supply unit of the two. I located all the electrolytic capacitors, as shown in the Fig. 2. You can clearly see how the top of the capacitor is popped up.


Fig. 2: (left) Electrolytic capacitors are located in the bottom left corner (right) side-view showcasing the "pop off" effect of a failed capacitor.


I desoldered all of the electrolytic capacitors and soldered on new ones. Most importantly remember the orientation of the electrolytic capacitor (they have a plus and minus, which must not be reversed!) and choose a capacitor with same or higher voltage rating. For its capacitance value you should be safe by choosing one with the same or larger, but it might not prove fatal even if it is even a little bit smaller in capacitance value.


Fig. 3: Remember orientation, voltage rating and capacitance value of new capacitors!


Fig 4. shows the power supply with replaced electrolytic capacitors. Compared with Fig 2., it is noticeable that the top of the capacitor is now flat.


Fig. 4: Power supply board with new electrolytic capacitors.

I assembled everything back together it worked like a charm.

The power of open-source

Written by Asger Bjørn Jørgensen, 2012-08-24

Hello everyone! Take a look at this little portable music player! As every other digital electronics device nowadays, it carries its own CPU, RAM, ROM and so forth. By understanding all these components, the awesome guys from Rockbox has created an open-source operating system. I installed this some time ago, and found out that there are several games in the package - this includes FreeDoom! Now I've made a video showing off my musicplayer (no, it's not just an mp3-player, please, it is compatible with almost all audio-formats on the market) playing FreeDoom using the Rockdoom WAD files.


As already mentioned in the YouTube-comments it's not the newest firmware of Rockbox. I installed the OS several years ago, and can't be arsed to update it right now.

Apart from playing useless games and countless of other weird plugins - why did I install this OS? Basicly this allows me to play several other audio formats, including .flac (Free Lossless Audio Codec), which allows me to rip my CDs and get the best sound quality to my player! Additionally the boot-time is several seconds faster and maneuvering the menus is done without lazy useless animations!

OpenRA dedicated server

Written by Asger Bjørn Jørgensen, 2012-06-11

Another news post about the open-source remake of the oldschool Command & Conquer: Red Alert!

I finally got a dedicated server up and running on my Eee PC 901 setup. It runs on our shared 100/100 Mbit at this dorm! Go download OpenRA and go to the "Nobelnet" server, it should give you superb ping times if you live near Denmark!

OpenRA

Written by Asger Bjørn Jørgensen, 2012-05-09

So, we all know it! Command & Conquer: Red Alert the first game in the C&C series released first for Microsoft DOS in 1996 and later for Windows in 1998! This game has a lot of great and popular sequels following it in the C&C series, but whoa! The first one is a real classic and the best Red Alert game ever made, so nostalgic. Good news for all of you out there who have not seen it yet and not played Red Alert for a long time!

Yep, you heard it! OpenRA is an open-source release of the first Red Alert game, with fixed and optimized netcode that opens up for a insanely entertaining multiplayer experience! Seriously go check it out, google OpenRA or go directly to their website! I assure you, it is a hell lot of fun. While downloading, get yourself in the mood with this video.




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