I came across a non-working satellite television set-top box, Tricolor TV DRS-5003, it was given to me when it broke down, its former owner simply bought a new one. The receiver broke down, as my friend said, not silently, as often happens when, for example, the firmware fails, the capacitors dry out or swell, a fuse blows, etc. He said that he heard a bang, and my first suspicion was that the capacitor in the power supply had burst, so I decided to revive it (as they say, an autopsy will show what happened there).
When I opened it, I saw a terrible picture; some parts of the receiver were even invisible due to dust.
First of all, I took a closer look at the fuse, although even without opening it it was clear that it was blown, that’s why it was a fuse, so that its thread would melt as quickly as possible, before serious damage to the device and home electrics occurred.
Having unscrewed the board, the power supply discovered the site of a “mini explosion”. In the photo below, the fuse and the spot on the substrate near the “epicenter of the explosion” are marked in red.
Using a vacuum cleaner and a brush, I cleaned the receiver of dust. Dust is often the cause of electronic breakdowns.
After cleaning, I found a place where the soldering areas of several parts had been damaged due to moisture, I cleaned them, coated them with soldering flux and re-soldered them until they completely fell off and the oxides shortened the parts with each other.
The bottom photo shows the actual place where the track on the board burst. First, I wiped this area with a cotton swab moistened with alcohol, since there was a black spot there too, partially cleared the varnish from the tracks, soldered it with soldering flux and soldered a piece of wire, so I restored the track. Then I assembled it, replaced the fuse, turned on the set-top box, and everything worked as expected.
Everything turned on, of course, but the buttons on the console panel had to be pressed hard, I forgot to pick up the remote control, and I like it when everything works as it should and I decided to clean them at the same time. Of course, they would have to be replaced, but since the nearest radio electronics store is one hundred and fifty kilometers away and, as luck would have it, there was no “donor”, I just had to clean it for now.
First, I unsoldered them from the board, then disassembled the buttons. The photo shows how the round plate has darkened. Carefully cleaned all contacts, including the plate.
After cleaning.
And I put all this stuff back together; glue helped me with this. To prevent everything from accidentally coming unglued, I slightly bent the iron frame at the back.
Of course, this is a temporary option, but as we know, there is nothing more permanent than temporary. I cleaned the mouse buttons in the same way and they haven’t bothered me for over a year. The main thing is not to scrape off the thin layer applied to the contacts and the plate, otherwise they will oxidize much faster.
Here is the actual result of my labors.
