In this video I cover repairing a KRK Rokit 5 RPG2 that isn't working and has the infamous black goo issue as well as some other issues.
Weller Soldering station I use:
Canada - https://amzn.to/2S7cxSj
For US: Amazon.com
https://amzn.to/2BqT2Nm or Digital version https://amzn.to/2Gp1vWT
99% Isopropyl for cleaning:
Canada - https://amzn.to/2R0SYh5
USA - https://amzn.to/2UUGLtc