Friday, December 2, 2016

Yamaha Amp Repair: Discovering the Issue

Last week, I floated the question of "what's wrong with my Yamaha amplifier?" As some of you might have guessed, the issue is capacitor leakage. (Check out the brown/green ooze coming out from the large capacitors above.

It looks pretty nasty.

There are only two capacitors that are leaking on the board, though, so the issue should be pretty minor to repair.

The capacitors are made by Nichicon, which was a major contributor to the infamous capacitor plague of 1999-2007. (The link goes to the Wikipedia article for "capacitor plague" - highly recommended.) In short, several manufacturers of capacitors, including Nichicon, manufactured capacitors with improper electrolyte through 1999 to 2002. This caused them to bulge, leak electrolyte, or vent, causing all sorts of problems from low capacitance to equipment failure to fire. Most of these problems were resolved by 2007, because the shortened capacitor lifespan caused products that included "plagued" capacitors to go bad by 2007. For this Yamaha amp, the problem remained unsolved until 2016.

The first step towards determining a replacement will be the measurement of the (identical) old capacitors. They appear to be 30 mm in diameter.

Their height measures 60 mm.

And the distance between pins, as seen from a bottom view, appears to be about 10 mm.

From here on out, it's simply a matter of finding a capacitor online with similar dimensions and specifications! More info coming soon.