Thanks for this thread! 
Since 2012 I own a pair of KRK Rokit 5 RPG2. I used them the first 3 1/2 years almost 24/7 and then on a daily basis, without big issues .... i guess after the first 2 years the first little hissing, humming and crackling appeared sometimes on monitor A ... it became more  frequently, longer, more intense until 2016 (Monitor B started after 4 years with minimal noises ) . It was most of the time gone when they reached temperature after 30 minutes. 
But since 2017 monitor A is always loud popping, crackling and humming ..(it is still operating fine between the frequently   events of buzzing,  - approximately every 20 seconds - in the second half of the video I turned the music off, then the membrane starts to freak out (youtu.be/GG_apVaXErk).... I have no abilities to fix it myself, so I hope I will find some repair-shop, which is able to do the recommended fixes, of this fantastic thread. I guess it was a big mistake to use them all the time after the first time the cracklings appeared and i am sure much more components on the board failured meanwhile...

wawwawwaw
Can someone tell me what kind of resistor do i need to replace it?

10-20k

Actually from the other photo on page 1 its 30k. I replaced both it, and the one adjacent with 22k and its working. Part of the standby circuit I believe. I don't think the exact value is critical but I havnt traced it out to see whether its a voltage divider or a current limiter, maybe it is a divider but since the standby pin can work over a wide voltage range it didn't matter.
 
I'd be replacing both those resistors and both diodes. I'd remove all the components from that area of the board and get rid of the goop completely otherwise you will have problems again in the future. Good luck

Well fellas, looks like we're moving to Gearslutz...

RP6G2 Schematics: https://ufile.io/rxb8i
 
 
 
 
 

RP6G2 Schematics
 

GanievRR
RP6G2 Schematics: https://ufile.io/rxb8i

Bingo!  Thanks for this!  Before this site shuts down, I plan on moving the bulk majority of info over to Gearslutz.  May I port this over as well?  Thanks!

2:43AM
 
Bingo!  Thanks for this!  Before this site shuts down, I plan on moving the bulk majority of info over to Gearslutz.  May I port this over as well?  Thanks!

Of course! At least you've already deserved it.

Hi,
 
When is the port to gearslutz happening? Be sure to post a link.
 
Add me to the list of poor souls who bought these awful KRKs. I should've known better when the first pair of KRK6s I brought home back in '13 had issues and I exchanged for a pair of 8s a few days later. Anyways, both mine are acting up now. I really haven't used them much to be honest. I curious if my black goo looks a whole lot 'cleaner' because of the light use or if the black goo issue is a problem that is isolated to a particular batch of black goo they used in manufacturer.
 
Nevertheless, one of my speakers has no amplification after opening the thing up (had the with weird volume changes for a while) and the other one is just starting to develop pops and very slight volume changes.
 
 
'The' resistor is the only thing that I can see that actually looks suspect (see pictures). No bulging caps that I can see.
 
I can't get links or images put in? WTH? I was going to post pictures, but can't.
 

Well, every time I try to post a response, it just won't post!
 
EDIT: I think I'm being either blocked or my post is crashing the server due to a posted link.  So just go over to GS and do a search for "Shade Tree Repair."  That'll get you to where you want to go!