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Shade-Tree Repair Guide: Fixing the Crackling/Static in KRK Rokit peakers
Old 30th October 2018
  #31
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Hey, everybody seems to have issues with the pcb with the amps on it but mine seems to work fine if i swap it with the one from my working speaker. So I did the same with the other pcb and bingo, well not really but the hf was gone again. So I suspect that the other board is faulty. This speaker has been repaired years ago when still in warranty and I think I've found the 2 caps they replaced. Thing is I don't know how to measure these caps. The power on all opamps is ok and there isn't all that much bgod on this board. Hope someone can lead me to resolving the issue.
Old 30th October 2018
  #32
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Richard Crowley's Avatar
If the problem is really one or two capacitors, simply replace them on speculation
If there was nothing wrong with them, then no harm, no foul.
Capacitors are cheap and replacing them is easy
Old 31st October 2018
  #33
Brb
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the awful glue gunk stuff they used has melted the inside one of my monitors. forcing me to mix in mono with actually helped my mixes a lot but it still sucks that one monitor is good and one is unusable
Old 1st November 2018
  #34
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I changed those two caps but the problem isn't resolved completely yet. I do hear a signal but it's very weak. So apparently those caps aren't the only issue here. There could be one ore more opamps blown as well. There are three opamps that have a different production code so maybe these were also replaced in the previous fix. I'm waiting to hear back from someone who is selling a oscilloscope so it's on hold for now.
Old 8th November 2018
  #35
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I've the same buzzing noise on a KRK 10S new out of the box.
Reading this post I've got the impression that the problem is that "glue":...
Old 22nd November 2018
  #36
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So I've come to the conclusion that I'm going to have to get all the BGoD off my PCB but before getting far enough into researching this, I did pull the two caps and resistors that OP originally thought were the cause on his board. My Rokit8's though had 4700uf caps not 3300. Would these be alright replacements?

UVY1H472MRD Nichicon | Capacitors | DigiKey
Old 22nd November 2018
  #37
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Richard Crowley's Avatar
Yes, those caps are appropriate replacements.
However it is very unlikely those capacitors are the source of the problem.
So replacing them has little chance of fixing the problem.
Old 23rd November 2018
  #38
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Quote:
Originally Posted by Richard Crowley View Post
Yes, those caps are appropriate replacements.
However it is very unlikely those capacitors are the source of the problem.
So replacing them has little chance of fixing the problem.
Yeah, I figured since I already took them off the board I'd replace them with new ones. I'll get to scraping off black goo while they ship and hopefully I'll have a working monitor again once the black goo is all gone.
Old 23rd April 2019
  #39
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Quote:
Originally Posted by cyberish View Post
I've the same buzzing noise on a KRK 10S new out of the box.
Reading this post I've got the impression that the problem is that "glue":...
A fellow KRK user sent me this. I would like to share it with you as there must be quiet a lot of people out there with the same issues...
Attached Files
File Type: pdf KRK_10S_Service_manual_05:2009.pdf (667.6 KB, 272 views)
Old 26th November 2019
  #40
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Does anybody happen to know what kind of resistors these are? Watts/Amps?

All of mine got blown due to the black goop....
Attached Thumbnails
Shade-Tree Repair Guide: Fixing the Crackling/Static in KRK Rokit peakers-2019-11-27_00-03-40_092.jpg  
Old 29th November 2019
  #41
Quote:
Originally Posted by avmack View Post
Does anybody happen to know what kind of resistors these are? Watts/Amps?

All of mine got blown due to the black goop....
In that location that you have circled are four components. From left to right, with the right being closest to the JP9 jumper and R108 big resistor, the components are as follows: DL100 and DL101 are both 1N4148 small signal diodes. RL106 and RL105 are 30K and 10K resistors, respectively. The resistors are 1/8W, but 1/4W will be just fine.
Old 14th January 2020
  #42
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Hi all and a big big thank you for creating and maintaining this thread - it has been an absolutely great help to me - so far.
To not blow up my post, I'd like to ask some advice for my problem with the BGoD.

I baught a pair of KRK Rokit 8 Generation 2, one of them with very low volume, no tweeter sound and a crackling yet quiet noise - so after reading these posts and opening up my Speaker I was not suprised to find the Black Goo of Death all over the place:
(I am not allowed image links yet, please refer to here: https://photos.app.goo.gl/z1FreRA1QQRN99xN9

I took a good 4 hours, a pick, acetone and my "everything will be okay" mantra and cleaned out all of the gunk I could reach. I removed the 4700, 1000 and two smaller Caps to get better access and inspec them - all caps looked fine, however the goo got way into both amps, so I also removed the heatsink, cleaned it out and hoped for the best (Lesson learned: the plastic foil between amp and heatsink was there for a reason - I know, don't judge, I am learning ).
On the upside: I got rid of the crackling noise, on the downside, the volume was still very low and no tweeter still (so same behavior as before my repair attempt.

My feeling here is that I need to replace both amps - do you agree with my asumption? The Caps still look fine and no other components were blown after my little "amp-tab-isolation-fail" apart from the main fuse.
I'd like to get your opinion on this - the last image in the album shows how the TDA7294 looked like after cleaning.

Thanks again so much for all the help that I already got!
/squirralex

*****EDIT 21. Jan ******
Part A: So I decided to change both Amps on the board with some success: The woofer is still quiet but louder and clearer than before. Still no sign of life from the tweeter. Funny effect is that when I turn off the power while music is playing, it gets louder just before going mute.
Now the funny Part B starts: When I checked the tweeter (wanted to look at it to source replacement), it seemed to be very losely connected - I re-attached and got it back to working -- yaay.
I then changed the back side of my good-rokit with the one on my bad-rokit and got it fully functional again - problem is obviously on the boards of the bad-rokit. So right now the only thing I am missing is loudness, which is about half in my bad-rokit compared to my good-rokit.

Last edited by Squirralex; 21st January 2020 at 08:10 PM.. Reason: Readability edit
Old 21st January 2020
  #43
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Oooooh YEAH, success, I brought it back to life!!!!
After the initial edit I was hungry for more, replaced two large Caps (just because they were the reason for many problems in all the other posts) and I got my Rokit back to full boost. I am playing them side by side now and they are sounding perfectly fine.

Retrospective:
I tried a lot and in the end am not sure, if all these steps were neccessary - just to be clear for anyone reading my post, cthink about the order of your steps and maybe save a little time and a couple of bucks.

- Initial crackling was probably caused by the BGoD.
- The missing tweeter was probably due to the weak connection in the front - So it ispossible that changing the TDA2052 was not neccessary.
- Missing volume overall: I am pretty certain that this was a corrupt TDA7294 (got better after changing it) AND the Caps (returned to full power after Cap replacement).

Thanks again for all the post and keeping this guide alive, next step is to clean out my good speaker so it does not turn bad ;-)
Have a great day folks, I am going to see how far I can go before my neighbours come and yell at me
Old 22nd January 2020
  #44
Quote:
Originally Posted by Squirralex View Post
Oooooh YEAH, success, I brought it back to life!!!!

- Initial crackling was probably caused by the BGoD.
- The missing tweeter was probably due to the weak connection in the front - So it ispossible that changing the TDA2052 was not neccessary.
- Missing volume overall: I am pretty certain that this was a corrupt TDA7294 (got better after changing it) AND the Caps (returned to full power after Cap replacement).
Congrats! Add another happy customer to the roster!

The BGoD is the root of all evil. Like in Time Bandits, it's actually "concentrated evil. One drop of that will turn you all into hermit crabs!" ...or at least destroy KRK's very own creation. Therefore, it is without a doubt the cause of the crackling and the failure of the components in your speakers, including the capacitors...not by physically touching them, but rather by conducting and causing leakage currents, high/stray voltages, and/or abnormal current draws.

Curious..which capacitors did you replace to return the volume back to normal? Should be a little number next to them, e.g. C105, etc. The high-freq and low-freq amplifiers both have MUTE circuits in their design...either that or causing the LF/HF drivers to lock down on a DC bias.
Old 10th February 2020
  #45
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Part 2: Speakter #2 starter crackling noise!

So when I repaired my first Rokit 8 G2 I also checked the board on the "good" speaker - I knew that I would have to repair that one too, eventually - that eventually was now: it started crackling a week ago and I had the time to go for it.
I cannot post images here so, please refer to my
Photo album here

The Pics are commented so you know what's what - I also marked some things this time
Overall it wasn't as bad as #1 - the pre-amp board was completely clean, the HF-Amp was clean, overall a little less far-spread goo. I had a good 3 hours of cleaning ahead of me.
I replaced the green-circled Caps, because I wanted to, not neccessarily because I had to It all went pretty smooth using my Cleaning-tools of choice. Also I found that Acetone was more eficient in solving some of the residual goo, that my pick didn't get.

It all turned out gread, crackling is gone.
Speaker #1 is also fine but again needs 4 Minutes of warmup - don't know what the problem is but for now, I am fine with it.


General advice for first-timer-goo-repairs:
- Go for it, you can do it!
- De-solder all the lerger caps and detach the cooler from the amps and board (See how much goo is inside the amp that you would otherwise not be able to reach
- have a proper pick with a fine tip to go under components
- Go for it, start wherever you feel like and just rotate the board as long as there is stuff to clean
- roughly pick away crust, vacuum off, pick more thorough and go in with acetone Q-tips in between
- don't be lazy

Just wanted to let you know!
Cheers,
me

Last edited by Squirralex; 10th February 2020 at 07:48 PM.. Reason: more info
Old 20th March 2020
  #46
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There should be a class action lawsuit to get these repaired. I went to replace caps in mine and one of the primary caps wasn't even soldered on. The goop was the only thing holding it in place.
Old 23rd March 2020
  #47
Quote:
Originally Posted by trakzero View Post
There should be a class action lawsuit to get these repaired. I went to replace caps in mine and one of the primary caps wasn't even soldered on. The goop was the only thing holding it in place.
Too late! Gibson, who owned KRK--and who didn't give a f%ck about anything (they also bought out Cakewalk and caused its demise)--went bankrupt back in 2018. Stanton Electronics, who apparently owns the KRK brand nowadays, hopefully isn't still gooping the $hit out of the boards.
Old 31st March 2020
  #48
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That's Great repair guide
Thanks



تعمیرات اسپیکر - تعمیرات بلندگو
Old 5th April 2020
  #49
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I've found that the BGoD starts conducting once it is thinned and heated. You may notice little bubbles that even look wet. Perhaps there is a chemical change or crystallization that occurs which converts the goop into conductive material. It is not very conductive though, tens of mega ohms. In comparison, licking my fingers and acting as a conductor, my body conducts far better.

I changed the power caps with Nichicon audio grade caps and the slight and occasional crackle is still present. Presence and power of the monitors seem better than new. I did not replace the corroded 2.2k resistors yet. I suspect the crackle will go away when I do. My Rokit 10s is humming, it doesn't have any BGod, I suspect the caps need replacing.
Old 5th April 2020
  #50
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Any specs on the capacitors other than voltage and capacitance? Such as...

Capacitance 6800µF
Tolerance ±20%
Voltage - Rated 63V
ESR (Equivalent Series Resistance) -
Lifetime @ Temp. 5000 Hrs @ 105°C
Operating Temperature -40°C ~ 105°C
Polarization Polar
Ratings -
Applications General Purpose
Ripple Current @ Low Frequency 3.1A @ 120Hz
Ripple Current @ High Frequency 3.565A @ 50kHz
Lead Spacing 0.394" (10.00mm)
Size / Dimension 1.181" Dia (30.00mm)
Height - Seated (Max) 2.047" (52.00mm)
Surface Mount Land Size -
Mounting Type Through Hole
Package / Case Radial, Can - Snap-In
Old 5th April 2020
  #51
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lovemonkey3833's Avatar
 

Also I have one of these KRK 10S subwoofers. If someone knows of a parts list to replace the whole damn board and crossover with something better quality/sound please post! I can't handle doing this specific type of work(replacing caps and all that). But unplugging boards and tossing in anew one is like building a computer, which I can do! And if it will get rid of that god awful noise and upgrade the crossover in it and parts that would be great!
We need a modder to do a mod on these KRK 10subs!
Get rid of that crap board and parts, toss in some quality parts and turn this subpar 400$ sub into something that actually works as it should! It should be able to be done for $100 or so! So spread the word, and someone come up with a mod for this KRK 10S subwoofer please and thank you!
Old 6th April 2020
  #52
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Quote:
Originally Posted by lovemonkey3833 View Post
Also I have one of these KRK 10S subwoofers. If someone knows of a parts list to replace the whole damn board and crossover with something better quality/sound please post! I can't handle doing this specific type of work(replacing caps and all that). But unplugging boards and tossing in anew one is like building a computer, which I can do! And if it will get rid of that god awful noise and upgrade the crossover in it and parts that would be great!
We need a modder to do a mod on these KRK 10subs!
Get rid of that crap board and parts, toss in some quality parts and turn this subpar 400$ sub into something that actually works as it should! It should be able to be done for $100 or so! So spread the word, and someone come up with a mod for this KRK 10S subwoofer please and thank you!
What sound issue are you having? Mine hums a bit. It's odd because if I turn on a combination of "wall warts" the humming goes away. It's behind a Furman AR1215 which also hums similarly. When the hum does go away with turning on wall warts, the AR-1215 stops humming to. Furman said the autoformer in the AR will hum a bit at times. I'm wondering if the caps being old (bought in 2002) the transformer works harder.

I'm purchasing the 6800, 1000, and 220 uf caps on the power board. I'll see if that takes care of the hum. I replaced the power caps in my Rokit 6 GR2s and the intermittent sizzle didn't go away. I'm also purchasing resistors to replace the damaged ones on the 6's. I'll see if that resolves the sizzle. Fortunately, the sizzle doesn't happen very often.

Time vs. money, the only reason to work on these vs buying a $500 set of monitors is that the KRKs I have have class AB amplifiers. Most stuff is class D now until you start spending $1,400 for a set. I may start looking around for a replacement though.
Old 13th April 2020
  #53
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Greetings, a bit off topic but off topic in a good way I hope. This is a VXT6 problem. I've had these from new for about 13 years and everything has been good up until a few days ago, when I became aware of an intermittent clicking sound coming from one of the speakers. I could recognise that click as the click you hear when you first turn them on. So some type of relay I'm guessing.

Now that monitor is not working. The light is on, and it still gets very slightly warm, but it does not get as warm as the other monitor that is functioning normal.

I am hoping that this is something that is easily repairable. I do not have the skills to solder but if I can identify a component then I'm thinking I can get the required parts before taking it to someone who can fix it. I have a Fluke 101, cheap but good enough to measure stuff if I know what I have to measure. I have not removed the back yet but I'm happy to do that if photos of the guts are needed.

Any suggestions on the best way to proceed from this point would be much appreciated.

Andrew.

P.S I should also add that I do not use the auto mute button but I have tried it in various positions to no effect.
Old 23rd April 2020
  #54
Quote:
Originally Posted by yummy fur View Post
Greetings, a bit off topic but off topic in a good way I hope. This is a VXT6 problem. I've had these from new for about 13 years and everything has been good up until a few days ago, when I became aware of an intermittent clicking sound coming from one of the speakers. I could recognise that click as the click you hear when you first turn them on. So some type of relay I'm guessing.

Now that monitor is not working. The light is on, and it still gets very slightly warm, but it does not get as warm as the other monitor that is functioning normal.

I am hoping that this is something that is easily repairable. I do not have the skills to solder but if I can identify a component then I'm thinking I can get the required parts before taking it to someone who can fix it. I have a Fluke 101, cheap but good enough to measure stuff if I know what I have to measure. I have not removed the back yet but I'm happy to do that if photos of the guts are needed.

Any suggestions on the best way to proceed from this point would be much appreciated.

Andrew.

P.S I should also add that I do not use the auto mute button but I have tried it in various positions to no effect.
Andrew, sorry for the delay. It's difficult to say what the issue may be with your speakers. The only way to start troubleshooting is to open it up and start nosing around. Usually, electronics troubleshooting starts with the basics: sight, sound, smell, and touch. Use caution around mains voltages though!

Start with the basics at first. Look for anything burnt, corroded, discolored/darkened, open solder joint/loose component, bulging and/or leaking capacitors (most small caps are dry inside anyway), excessively hot components (i.e. "smells" hot), etc.

Fluke 101 is good enough for most troubleshooting. Some caps can be tested (out of circuit), if needed, and voltages can easily be checked.
Old 23rd April 2020
  #55
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Quote:
Originally Posted by M.Retra View Post
...snip...

No worries, thanks for the reply. Truth be told I'm probably out of my comfort zone on this, but I eventually did track down a small audiophile specialist outfit that one of the suppliers of krk use for their repairs. I will try to obtain as much detail as I can and post back here in a couple of weeks, in case the info is useful for others in the future.
Old 26th April 2020
  #56
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Here is the repair report, and as per this thread, it was also a glue caused problem. I post this report in case it is of some use to others.

The problem was a corroded track on the circuit board which controls the operation of the main power relay. The continuity of the circuit was intermittent. The corrosion was due to the application of glue to a nearby connector. The use of glue is minimal on the amplifier board, so I don’t expect it will give other problems. The glue at the fault location has been removed and the track has been repaired. The relay operation and audio is now all fine.

I was given some more specific information so I can open up my other VXT6 and at least see if I can catch a problem before it occurs in the other speaker, or at least see if it's likely to occur. So here it is...

There is not much glue on this [VXT6] board; just around the speaker wire
soldering, around the plastic shroud around the input module and the power
connector where the relay circuit track was located. It was bad luck that
the glue ran down onto the circuit board. There isn't as much glue as I've
seen on some other model Rokit amps which are usually not economically
repairable.

The only way to be sure about your other speaker is to remove the amp module
and check if the black glue has run onto the circuit board at the base of
that connector. You would need a 3mm hex key or driver to undo the screws.
The amp assembly usually sticks and is tight to get out of the box.
Sometimes the amp unit will dislodge by holding the speaker with the back
down on a table and bumping it. It's small white connector J5 that has 3
wires (2 green and 1 black I think) that come from the power transformer.
The relay control track runs on the top side of the circuit board between
the connector and the edge of the circuit board.
Old 8th August 2020
  #57
Gear Maniac
 

Quote:
Originally Posted by trakzero View Post
I've found that the BGoD starts conducting once it is thinned and heated.
Yes, and this mainly occurs next to the higher wattage(bigger) resistors. The black goo will eventually turn brittle and flake off but by this time it has already done it's damage. The goo that is still rubbery is more than likely not an issue but removing it wouldn't hurt.
Old 3 weeks ago
  #58
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Quote:
Originally Posted by peterc View Post
I had a 'ghost' repair on this unit.

I cleaned the PCB a second time with Acetone, no fix, still had a 3.4v DC offset on the tweeter.

Got the schematics and I could see exactly where to look, turned on the unit to check the voltages and voila!, no DC offset!

Burnt in for 24 hours and all good, thanks to everyone for their help.

Peter
Looked for those schematics for KRK Rokit 6 everywhere, didn't find them. Care to post them here please?
Thank you
Old 2 weeks ago
  #59
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Perfect report

Great fault finding report and sharing.
I've a KRK RPG2 8 and similar issues.
Let's see if I can make it ok.
Regards.
Attached Thumbnails
Shade-Tree Repair Guide: Fixing the Crackling/Static in KRK Rokit peakers-2020-9-11-22-34-33.jpg   Shade-Tree Repair Guide: Fixing the Crackling/Static in KRK Rokit peakers-2020-9-11-22-34-16.jpg   Shade-Tree Repair Guide: Fixing the Crackling/Static in KRK Rokit peakers-2020-9-11-22-33-55.jpg   Shade-Tree Repair Guide: Fixing the Crackling/Static in KRK Rokit peakers-2020-9-11-22-34-4.jpg   Shade-Tree Repair Guide: Fixing the Crackling/Static in KRK Rokit peakers-2020-9-11-22-33-2.jpg  

Shade-Tree Repair Guide: Fixing the Crackling/Static in KRK Rokit peakers-2020-9-11-22-32-50.jpg   Shade-Tree Repair Guide: Fixing the Crackling/Static in KRK Rokit peakers-2020-9-11-22-31-34.jpg   Shade-Tree Repair Guide: Fixing the Crackling/Static in KRK Rokit peakers-2020-9-11-22-31-45.jpg   Shade-Tree Repair Guide: Fixing the Crackling/Static in KRK Rokit peakers-2020-9-11-22-32-19.jpg   Shade-Tree Repair Guide: Fixing the Crackling/Static in KRK Rokit peakers-2020-9-11-22-32-31.jpg  

Old 2 weeks ago
  #60
Quote:
Originally Posted by Athhos View Post
Great fault finding report and sharing.
I've a KRK RPG2 8 and similar issues.
Let's see if I can make it ok.
Regards.
Yep, the goop got ya! Some of those resistors are definitely toast. The glass diodes may be salvageable. The pins on the amplifier IC are fortunately goop free.
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