I was handed a Mitsubishi Tachometer with what seemed like a blown capacitor. Apparently, these meters have issues with that component because I was shown how it can be repaired on YouTube. I had to go down to Pasar Road since my components stash does not have any capacitor of that particular value, which was 10uF, 25v.
Yeah, going there on a Sunday was more like a hit and miss since the ‘electronics’ side of the shops were always closed. But thankfully, I got the much needed component before it closed later on.
THE METER
This was taken off from a Proton Perdana otherwise known as the 7th Generation Mitsubishi Eterna. The main issue was that the meter showed it was very, ‘heavy’ and does not react to the full RPM range. Taking a quick look and also the YouTube video, the main culprit was the axial electrolytic capacitor. Although this meter’s capacitor looked more like a custom, the value was the same.
I am quite surprised that Denso has a hand in making meters as I always liked the name to reliable car Air-Conditioners.
This was the first sign I saw that the capacitor had blown. Usually, their tell-take signs were exploded tops but here, it’s just leaking electrolytes.
The electrolytes also affected the copper tracks but after some cleaning up with IPA and thinner, it wasn’t that bad anymore.
Because the markings of the affected capacitor is not reliable, I had to trace the circuit a little. One of the clue is the polarity of this Diode. It has a silver band which makes that the negative end. This, is very important.
Turning the board on the solder side, we can see that the positive end of the diode (arrow) is soldered on the positive track (yellow). The capacitor’s polarity is now determined as it’s positive leg (arrows) is also soldered to the positive track.
After cleaning up with some IPA and thinner, most of the electrolytes have disappeared but not all.
The 10uF, 25v capacitor with no markings on its negative side. I suspect the silver dash (on the left) could be the marking for the positive end. I won’t know unless I de-solder the other capacitor in the circuit board as well.
So, with the repair done and the meter passed back to the owner, it will be a matter of time before we both know if the repair is a success or a failure. I mean, he needs to open up the dashboard to connect the meter…
