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Old 2nd December 2017
  #2
CAUTION: Repair at your own risk. Always be aware of high-voltages which could shock you, i.e. be especially careful around "mains" voltages, amplifier rails, switching power supplies, and high-voltage capacitors. Obviously, you don't want to be touching these while energized, and some capacitive circuit retain a charge.
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Thank you to the KRK manufacturing team for the Black Goop of Death! This $*%& was intended to "hold down" and protect larger components and wires from vibration. Too bad it caused more failures than its intended purpose!

The Black Goop of Death


I encourage all those who are repairing their Rokits to clean out the goop between components. Seriously, this stuff makes a complete mess. It hard and you must either chisel it out or find another means. Rubbing alcohol doesn't seem to penetrate the stuff, but it does clean up the area after it has been removed. Acetone may prove to be more effective.

Location of previous repair last year, the replacement of the 2.2k ohm resistor, which was cooked. Note the corrosion of the jumpers. I replaced the capacitors (removed) in this area as well, as they both were bulged and had failed. The BGoD got 'em!



All cleaned up and much better!



Another area that was cleaned up. This area also sees raised voltage levels (+/-20V) and the jumper and the components showed signs of corrosion. I also replaced these capacitors as well (not shown).



After cleaning up all the areas shown above, the speaker turned on and sounded good!

So my advice?
  1. Check the boards for corrosion and areas where the BGoD covers multiple components, especially jumpers.
  2. Remove the BGoD using chemicals, a pick or X-Acto blade. In my case, I used a hot soldering iron with a chisel tip + X-Acto + isopropyl alcohol. If you use your soldering iron, then be sure to clean it well afterwards.
  3. Replace burnt resistors and bulged capacitors. Overall, I think it's a good idea to replace all of the power capacitors. The two in the middle are 1000uF 35V electrolytic caps. I replaced them with 50V versions.