Mackie HR624 Repair

Mackie HR624
Mackie HR624

I love my Mackie HR624 monitors.  Let’s face it, guys need speakers.  Bi-amplified with 40w for the tweeter, 100w for the woofer, a passive radiator, selectable equalization for various speaker placements, phase correction, extremely flat response…what’s not to love?   When I am enjoying some morning sitt’n time with a nice cup of joe in my hand, I like to crank them up (along with an BagEnd ELF subwoofer system…flat to below 18 cycles) and enjoy some tunes while checking email.  I also use them for music and video production monitoring and they never fail to provide an accurate representation of the source material.

I bought these speakers maybe eight years ago and they have performed flawlessly…until a year or so ago that is.   These speakers have a circuit that automatically turns on the amplifiers when an input signal is detected, and you can see the pilot light on the front panel come on when this happens.  What happened was that one of the HR624s started having trouble turning on.  The pilot light would flash on and off a few times before the speaker would finally stay on.  This gradually got worse and worse, taking longer and longer to switch on, until a few weeks ago when the speaker would not turn on at all.  OK time for some sitt’n time…with Google open on the iMac for some searching for others with similar problems.  Sure enough I found a site which identified C65 as the culprit (that page no longer appears to be online unfortunately).  C65 is a 63v 4.7uF electrolytic capacitor and I found an ebay dealer who sold me twenty five of them for about $8.  OK time for some speaker surgery!

Note: I am going to describe how I repaired my own speaker since it might be of interest, but I am not encouraging you to try this yourself.  These are the original 624s were long out of warranty.  I used to work at a recording studio as a tech and have some limited experience making basic fixes to various kinds of audio equipment, but you could probably wreck your speaker if you did this incorrectly. 

Mackie HR624 ready for surgery

I did this work in our kitchen with a towel on the counter and the 624 on its face so I could easily access the amplifier module on the back (unit unplugged from AC of course).  To remove the module I needed a Torx wrench.  I don’t remember the exact size, but if you don’t have a Torx you can buy a set at a local hardware store.

Mackie HR624 amp module removed
Here is the speaker with the amp removed. That is the rear passive radiator you see.

When I got the module off  I found capacitor C65 pretty quickly, but in order to get to the back of the circuit board where the solder traces are it looked like I’d have to completely disassemble the amplifier module. Not something I wanted to try.  With nothing to lose since the speaker was broken anyway, I bent C65 back and forth until its leads broke off exposing the two small holes in the circuit board and the solder in each (you can click on my photos for larger versions)

location of C65
location of C65
electrolytic capacitors
new electrolytic capacitors
capacitor held in heatsink clamp
capacitor held in heatsink clamp

I then took one of the new capacitors I had purchased, trimmed the leads down to a reasonable length, clamped the leads in a heatsink (to avoid heat damage), and gingerly tinned the leads leaving a tiny blob of solder at the end of each.  Finally I positioned the new capacitor leads so that they were resting on the solder/holes from the old capacitor.   Since this was an electrolytic capacitor it was important to note the correct polarity.  In the this case the negative side was facing the big toroidal transformer.  An LED tactical flashlight positioned to shine into that area was critical to really see everything clearly (guys also need high-lumen tactical flashlights).

new capacitor in place
new capacitor in place

Finally using a fine tip Weller soldering iron I very carefully melted the solder in the holes along with the blobs on the leads.    The result was a pretty decent soldering job with minimal dissassembly.  After re-assembling the speaker I was happy to see that it worked perfectly!  It now turns on and off exactly as it should and hopefully will last for several more years.  Time to listen to some tunes.  Sitt’n time.

This Post Has 105 Comments

  1. Wayne Bangert

    I have the same problem. I sent it to sweetwater sound for a repair. They are idiots. They say there is nothing wrong. I am getting the speakers back and I will replace the cap as you did. Thanks for the info.

  2. Jonathan

    Thank you for this sir! I was on the verge of purchasing new monitors and ran across this page. My capacitors arrived in a day and I installed them no problem. (First time soldering) I successfully disassembled the amp. It was actually much easier than it appears to be. Anyway, after replacing C65 on both monitors, I was back in business. Thanks!

  3. Ken

    Hey I got the same speakers and looking to replace on of the woffers
    How much more work do you think it would be to replace it?
    Thanks

    Ken

  4. Gabriel

    I really must express to you my gratitude and sincere thanks for having posted this DIY repair. My HR624’s recently failed due to an issue remarkably similar but somewhat different. The similarities were quite significant of course and your page was the only similar issue that I could uncover after several hours of exhaustive searching. This, of course, happened at the worst time. I’ve been working on a several thousand dollar recording/mastering session with a reputable local “prep” school and I’ve relied on these speakers for over 8 yrs. So, this DIY was my most cost effective and likely repair. Mackie no longer offers the PCB assembly and have become very non-forthcoming about possible fixes, also several authorized repair shops locally plain refuse to work on Mackie equipment anymore?!?!
    Anyway, Thank you very much for your research and insight.
    -Gabriel

  5. Luke

    Hi, This is the coolest page I have found in ages. I have these monitors and I have exactly the same problem. It’s so awesome that you shared this with the world. I am going to try it tomorrow. Thanks so much!

  6. Jose

    Hi from Spain, i have just the same problem with my hr624, really the best speakers for studio i have had.
    My hr624 did the same, it was ON, Off, ON Off..úntil just some days ago did not swich ON more.
    I found you in Google, i thought like you jejejeje and im going to try replace the c65 capacitor.
    So i give you thank you very much for do public your experience.
    I hope much people found the answer to this problem doing this.
    King regards.

  7. emilio

    man you are an idol! i have exactly same proble, now i have to admit soldering scares me a bit, but i will do when speaker go completely dead.Any of you had aslo the issue of having the on off bug when turnin on the volume? mine seems like has to “warm” properly before allowing louder volume

  8. Rozzer

    Hi,

    Just wanted to say a huge thanks for documenting this. I had exactly the same problem with one of my HR624s and this fixed it perfectly.

    – Rory

  9. jcb

    Have run into the same issue with my pair of HR624’s that I’ve had since about 2006.

    It started happening very subtly on one monitor… the light flashing on and off and sometimes staying on, but over time (about a month) it would eventually just not turn on at all. After a few weeks of using only one monitor, that one also began to exhibit the same symptoms and now won’t turn on at all either.

    Really appreciate your write up on this. Not very competent soldering stuff myself but I will give it a go, worst case scenario they’re already broken 🙂

  10. meeloo

    I had the exact same problem with my pair. One of them kinda revived by itself but the other one was totally dead for years and I kinda gave up on them until I saw your post! I ordered the parts online, received them today and started the fix. I didn’t feel like pulling on the component and went the long road: I have completely disassembled the monitor to access the soldering face of the PCB where I could unsolder the faulty condenser and solder the new one easily enough! It’s now back on my desk and plugged in, working perfectly!
    Thank you so much for this page! You basically saved me 1000€ in new active monitors :-).

    Cheers from France,

    meeloo

  11. Ashley Wood

    Have the same problem on a H624 MK2, Any Ideas if the repair process is the same?

    1. cfbrush

      Sorry but I don’t know if the process would be the same for the H624MK2, but it might well be if the circuit layout is similar. You could open them up and take a look. If you do manage to fix it could you post it it back here? I’ll add it to the article for those with 624s. Thanks!

  12. Andy Britton

    Thanks for the info – this worked a treat and I’m back in business!!

  13. Bob Bradley

    Thank you so much for sharing this fix. As with many other 624 Mk1,s mine unfortunately started going the same way. Whith the fault the only way I could use them was to basically leave the faulty speaker on 24/7. I,m now pleased to report that with your excellent article I have fixed the fault. Thank you again.

  14. Patrick

    I just replaced C65 on an HK624 MKII and it solved the problem. The cap is in a different spot but it is clearly marked. Local electronics “experts” charged me $65 for their “professional” diagnosis which was replacing the whole board for over 1/2 the price of a new monitor. My eternal gratitude for sharing this with me. Thankyou! Thankyou! Thankyou! 🙂

  15. Ron James

    Can you send me one of your capacitors? Seems like you might have a lot extra. The web link at Mackie has been removed it seems.

    My speaker did this about a year ago. Then it just repaired itself. Now its doing it again.

    I’ve soldered before but don’t have a heatsink clamp. Is that necessary to dissipate the heat while lowering the cap down onto the board?

    Thanks,

    Ron

  16. Ron James

    Funny, now its working if I feed it extremely low level audio. As soon as I turn it up to normal levels (and I listen pretty quietly in my studio) it starts to blink on and off. And even stranger, after I’ve listened to it at low levels for about a minute or two, it is working again.

    I was wondering why it was going off and on at such a steady pace… capacitor makes sense.

    PS Did I say I’d be happy to pay you for one? Although I do have your specs (63v 4.7uF electrolytic capacitor) does this describe the part in a regular electronics store? I mean do they have some with leads coming out of both ends or is this specification describing the one with two leads coming out of the bottom as your picture?

    thanks,

    Ron

  17. Gabriel

    Well I’m here again to refresh my memory of this fix. I knew it would probably be coming before too long. I fixed one about a year ago so I just knew the other had to fail eventually. Yep, same issue! I just felt the need to send you a hearty thanks and appreciation for your insight and research. These HR624’s really are a wonderful monitor and I’m so very happy that you have provided the world with this fix. Much gratitude to you! -Gabe

  18. Gabriel

    On another note, I’ve been purchasing ELNA capacitors for this and other projects. You can find these in many of Tascam, Teac products. They are very good quality and will last for a long time. Just to let you know!

  19. Ron

    I just wanted to chime in that I made the fix too… according to the instructions. Perfect. Although I took the board out too. Not too much work just 6-8 phillips screws and 4 Allen screws.
    Thanks for this blog.

  20. Sung Song

    Thank you for your post. It saves precious time and efforts for me. I would do same steps you did if I couldn’t find you post first. Thanks bunch. You’re the man. 😉

  21. Roger

    This procedure also works for the H624 MK2. Same capacitor, and same traces. Thanks so much for sharing this page!

  22. Dick

    Big thanks for publishing this. My 624 Mackies show the same behaviour. Too bad Mackie does not publish a mod on their website to fix this. Cheers from Holland!

  23. Richard Lodge

    Just a quick message to say a massive thank you. Had exactly this problem, got quotes from a number of repair shops, was looking at £150 minimum. some charge £60 just to take a look at the thing. Thanks to you my speakers are now working perfectly for a 100th of the price. Brilliant!

  24. Ashley Wood

    JUST TO LET ANYONE KNOW THIS FIX ALSO WORKS ON HR624 MK2 THE CAPACITOR IS THE SAME ALTHOUGH IT IS LABELED C76 IN THE SAME LOCATION PROBABLY A MINOR PCB CHANGE. BUT YES WORKS FINE.

    1. diego

      THANK YOU

  25. Threlly

    Thanks for the C65 tip, followed your advice and repaired a 624 this morning.
    All great now.

    Many thanks,
    Threlly

  26. s2arto

    A schematic for the 824 is available at bmamps.com. The parts layout appears to be considerably different, and may not be of any help when servicing the 624.

  27. DJP

    Same problem here and this fix worked perfectly! I went the long way and removed the PCB to solder the cap from behind the board. I started to regret it after I realized how many screws I had to removed to get to the bowels of the Mac. But after several hours and some gentle persuasion I was able to replace the cap successfully!!
    I’ll wait until may other speaker goes out and do the same thing….after all I still have 24 caps left!! Thanks for your post….really really helpful.

  28. Nick

    I’ve held onto these broken monitors for year.. Read this post and tried it! They work perfect thank you so much.

  29. Steve Smith

    C65… good fix

    This cap gets ripple on it as it dries out and this causes the mains failure sensing to have look like a low voltage signal hence it wont start.

    You can use a 4.7 35V ceramic on the bottom of the PCB and then it should never fail again…

  30. Tjeerd Sietsma

    Another HR-624 was fixed thanks to your article.

    One of the two monitors was having problems in the first few years that they were used. After passing a quite firm (but well within the technical specs) audio signal to them, one red light just wouldn’t turn off for days. And now for a year or so the same monitor has the problem you described. It’s a good thing your article is still online, also because Mackie has (re)moved the page that you referred to. After having read your article with its happy responses I decided to give it a try, even when the monitor wasn’t completely ‘dead’ just yet.

    To be on the safe side I ordered 10 capacitors online because the shipment cost was about 7 times as high as the cost of the capacitors, making the total repair cost about € 8,=. Also, spare capacitors allow more than one repair attempt which could be useful for whenever the second monitor decides to quit.

    To open the back of the monitor an extention for my cordless screwdriver was needed to get to the screws. After having opened the monitor a first attempt failed; the legs of the capacitor were cut somewhat short, and the soldering iron was somewhat large for this task. After turning on essential lighting to get a clear look on the C65 area, and using fingers to hold the new capacitor, my second attempt succeeded and the monitors are shining again. BIG THANKS to your article!

    I noticed just now that the green LED of the repaired monitor is much brighter, like a new LED. The green LED of the other monitor is fainter, like the LED is attached to an almost empty battery.
    Is this because of the new C65? Anybody has the same experience?

  31. eyal

    Hello.
    just wanted to join the others and congratulate you for this very very helpful tutorial..
    ive been searching for information about this for quite some time, this problem started occurring 2 years ago, but then it got fixed by itself, and then returned a few days ago. i decided not to wait and replace the C65.
    it worked like a charm! thanks a lot. i did it the same way as you – removing the entire board seems very scary, looks like there obstructing parts that make removing the entire board very difficult..
    but im still looking into taking appart everything for the second speaker thatll break eventually… if anyone has a youtube tutorial thatll be great.

    Tjeerd Sietsma: yes, my Led also seems to shine brighter than the second untouched monitor.
    p.s: ive used a 4.7mF, 100V capacitor, no problems.

  32. Erkal

    WOW, Sir, you are THE man!

    Thank you very much for taking the time to inform everyone about this fix. After years of constant and random power ON/OFF’s, they had given their last breath a couple of years ago, yet you resurrected them from the dead for a total of 20 cents and half an hour of soldering, very much appreciated!!

    Thanks again!

    Erkal

  33. Tjeerd Sietsma

    Eyal, thanks for letting me now! Just for the sake of equal LED brightness I might try to ‘fix’ my right monitor as well 🙂

  34. David

    It worked for me although I’m pretty bad with electronics. If only I could find a tutorial like this every time some electronics goes wrong…!

    Thanks a million

  35. Brian

    Fantastic! Worked like a charm. My HR624 had been a paperweight for over a year. Add my appreciation to the long list!

    Best –

    Brian

  36. Joe

    Love these monitors and my heart sank when this issue started. It’s absolutely worth it for me to try and revive!

  37. Matana Teknik

    Thnx another pair of MKI are working again…..but looking at the amp pcb and the brand of capacitors Mackie used i would suggest a total recap of that Chinese capacitor lot…especially the two main caps are really bad…..change these for a high grade cap and your bass response will improve. My 2 cents.
    But yet again thanks for your site!!!

    br, Dennis Matana

  38. telecastic

    Woohoo!
    My hr624’s are good as new. You are a god. I had one bad and one good, did ’em both. I bought 10 caps have 8 left. If anyone out there needs a couple, email your address. I’ll send you 2. Send me in return 3 Spacebucks. Honor system.
    telecastic@verizon.net
    Thanks a gazillion.
    Scott

  39. Ben

    Hi,

    I bought Malloy capacity at the same rating. After I solder it and plugged in the power cord. It pop and smoke arised. The whole capacitor exploded. Wonder what I did wrong.

  40. Ben

    Ah crap.. wrong polarity. Resoldered correctly now but I guess I blew something else.

  41. Scott

    Wow!
    Unbelievable!!
    I was SO happy to find this!
    I also had one good one and one bad one!
    I ordered the capacitors and I was sent the wrong ones..
    Then I reordered and received the right ones….or so I thought.
    I brought both HR624s..the one that worked, and the one that didn’t, to my local music store to a tech who said it would be a piece of cake to fix them.
    Now both of them don’t work.
    He’s reordered more capacitors saying he needs ones that have (+) and (-) identifiers on the capacitor in order to know which way to install them….
    Does that sound right?

  42. Stuart

    You are my hero. I am absolutely ecstatic. My right HR624 has sat sadly silent for months, and now with a $0.25 part (I had to buy five!) I have restored my stereo sound!
    Thank you for making this knowledge available.
    -Stuart.

    1. Stuart

      Me again. I just finished fixing my left HR624! It took me a while to find the bag of capacitors I bought for $1.25 two years ago, but I’m back in stereo again. Thank you for keeping this page here.

  43. Frank B

    Big help … thanks! Now that I see how many hours these replacement capacitors are rated for (2,000), it’s no wonder I’ve burned through two speakers in 8 years. I keep my power always on and use these as my PC speakers, which I never turn off. Lesson learned. I’m changing to standby mode on the power switch.

  44. Victor

    Awesome!
    Thank you immensely for taking the time and trouble of posting the fix and photos.
    I concluded the repair of C65 and all of the other caps(preemptive precaution)utilizing
    the best Rubycon caps.
    My speakers are alive again!
    To have knowledge is great even better is to share it and assist your fellow man…….bravo, SIR !

    And as you so eloquently stated: now it’s Sitt’n time………………pop open a beer and listen to some righteous tunes.

  45. Jason

    Just did the repair! Works as good as new! Thanks!

    Surprised that this is such a common issue.

  46. Sitting Time

    Well it’s been almost exactly 3 years since I wrote this post, and now my left side HR624 is failing in exactly the same way. Hmmm….were did I put that extra capacitor. Might have to sit and ponder that a bit before diving into the repair.

  47. Costas

    Great post and info. Will start the repair on mine now, thanks (wonder if it will fix the slight hiss also)

  48. Justin

    Many thanks! Worked great on my 624 which wouldn’t turn on any more. Very grateful for the detailed write up.

  49. Harold

    Thanks it worked on my Mackie HR624 i found a old board off something else and remove a 4.7uf 400v capacitor it is bigger in size, but solder some wire legs on it installed and worked great ! Had it fix the same day i found your info. Thanks i now have my fine Mackie HR624 High Resolution Studio Monitors working great. I will order from Amazon the 4.7uf 63v Capacitor just incase the other go out. Thanks.

    Found 10 4.7uf 63v capacitor on Amazon Prime for $7.61 http://www.amazon.com/gp/product/B00LWT3LRM/ref=olp_product_details?ie=UTF8&me=

    Or 5 for $5.83

    http://www.amazon.com/Aluminum-Electrolytic-Capacitors-Leaded-6-3×11/dp/B00LWT3PO6/ref=sr_1_3?srs=3445922011&ie=UTF8&qid=1453002745&sr=8-3&keywords=4.7+63

  50. Luke

    Thank you so much for this. Was completely the problem I was having. Fixed in 20 mins. Star!

  51. Sean

    The links to the caps on Amazon are for non-polarized capacitors. Has anyone actually used these? I ordered them, but not want to try them if it truly requires polarized caps. I googled non-polar vs. polarized and seems it shouldn’t matter, but I don’t want to blow anything in my HR624s if I should just order the polarized versions and wait another couple of days.

    Thoughts or Experience on that?

  52. Si

    I was so chuffed to find this page, but sadly it wasn’t the issue with my duff HR624. There are 2 x 800mA internal fuses that protect the transformer, and one of these had blown. A replacement blew straight away, even with the transformer secondary disconnected from the PCB, so I checked the resistances across the coils – it measured 55 ohms between the 2 primary windings (between yellow/red & black), and about 15 ohms across each winding. I wasn’t sure if this was normal, until I eventually realised that stereo means I had another to compare with! Sure enough, the transformer in the working speaker measures infinite resistance between the two primary windings suggesting the transformer is dead, presumably with a short blowing the fuse each time. Putting the good transformer in got the speaker working again, so I’m now on the hunt for a replacement transformer.
    To answer the question above, my understanding is that non-polarised caps are fine in this situation, it’s just harder to find them at this value – polarised are cheaper & smaller, though farnell in the UK had some 4.7uF film caps quite cheap – order code 1006056. Although I don’t think I’ll need to swap C65 yet, I’d probably use these instead of an electrolytic, to save doing it again in 10 years! It is easy to take the whole assembly out & would make the cap fix easier – some screws at the back & 4 tiny star type Allen keys is all.

    1. Martin

      Hi Si,

      I came across your comment as I’m having the exact same issue with one of my Mackie HR624 MKII. The transformer (part 0022712) is dead and you can even smell the burning bits. I confirmed it by swapping the good transformer from the other speaker.

      I’m wondering now where I can find a replacement, how did you end up fixing it?

      Cheers,
      Martin

  53. Si

    If anyone else is looking for a replacement transformer, you need a 120VA toroid with split primary windings, outputing 29VAC, diameter no more than 9cm across. This is the nearest I could find in the UK – the output is 30VAC rather than 29 but it’s near enough, as the important stuff goes through a voltage regulator anyway:
    http://www.airlinktransformers.com/chassis_mounting_toroidal_transformers/chassis_mounting_toroidal_transformers_standard_range/CM0120230/
    The green wire to the chassis is not a safety feature but to stop interference and voltage spikes getting into the main power supply, so choose the electrostatic option on the website above will cover this, as well as the split primary windings.
    Alternatively this firm will rewind the original transformer for you:
    http://www.canterburywindings.co.uk/index.html
    Good luck with it.

  54. Imran Anwar

    Loved my Mackie H624 speakers but had not used my studio set up in several years. Spent the day rewiring everything and just got done only to find that the only thing that did not turn on is the pair of Mackies. Truly disappointing. But glad I found your page and try out what seems to have worked for so many. My thanks anyway in advance assuming I’ll get to doing the repair in the next 8 years considering my To Do list going back to 1989. LOL.

  55. Si

    Just to update – it works, never been so pleased to see a green LED come back on.
    Wiring for the CM0120230 Airlink transformer is below, but transformers vary so don’t rely on this if it’s not the same model. Best to test you’re getting around 30v AC on the outs before connecting the secondary to the PCB.
    1mry: transformer blue -> yellow PCB connector, grey -> black PCB, violet -> yellow / red PCB, brown -> black / red PCB
    2nry: red -> 1 brown PCB, yellow -> other brown, orange & black both connect to brown with yellow stripe PCB (ground).
    green & yellow -> chassis earth.

    1. Peter

      Another year on and this thread is still delivering the goods! I had exactly the same problems as Si (cheapo Chinese transformers Mackie?) and replaced it with the Airlink CM0120230 as per Si’s post. All good so far, so a huge thanks to Si from me.

  56. Robert

    Also curious if non-polarized caps will work and from what I’ve read they should be fine. As I understand it, non-polarized are more expensive than a polarized cap because they are two polarized caps together. No one responded to Sean because maybe it’s obvious to most but will give them a try in a week or so and respond back.

  57. vince

    Thank you so much for posting this repair. It was exactly my problem and the fix worked perfectly.

  58. Paul

    It worked! Just fixed my dodgy HR624 with the help of this article… total cost = 20p
    Thanks !
    Paul, UK

  59. Rob

    Thanks so much for this. I was hoping to send my monitor off to the ‘approved repairer’ here in the UK (£100 just for taking the cover off) once I had the money, but this information saved me the cost…. £1.49 delivered for 10 capacitors and about half an hour and it’s back from the dead.

    Thank you so much.

  60. Bill S.

    I ran into the same problem (HR624mkII). After reading this article I gave it a go. The speaker now works perfectly despite my terrible soldering skills lol. Thank you, thank you, thank you!

  61. Jesse

    Not sure if anyone is still reading this, but it’s worth a shot. So, I thought that I had the same problem, but replacing C65 didn’t correct the issue, and I actually have both 800mA fuses blowing. I then thought, like Si, that maybe the transformer was bad. After some testing though, I don’t think that’s the issue. The fuses ONLY blow when the transformer secondary is connected to the PCB. I took voltage readings at the secondary without it connected and I was getting 33VAC across brown and brown/yellow (66VAC across brown and brown). Also, input resistance is infinite on the primary. Could the transformer still be the problem? (I haven’t gone down the road of trying it with the one from the working speaker) Is there something in the transformer circuit (downstream of the secondary) that could be causing the problem? What short would be blowing both fuses?

  62. Clawmd

    I pulled the board and replaced c65. Presto! It worked. Removing the board requires 4 screws on the board and 2 screws from the sides. There are 2 nylon snap fit retainers that poke up into two holes in the board

  63. Dylan

    Thank you so much! Did the trick. Really not too bad to disassemble the whole thing. Whole process took maybe 20-30 minutes. I am so thankful for the tip.

  64. diego guerrero

    Hi, I have this problem, the auto swich not work always on, but in my HR 824´
    Can I fix too use this help on this diferents monitors?

    Thanks.

    1. Max

      Hi Diego, if you found the answer, please pass me the info, I have the same problem on my 824 MK2. Thanks.

  65. Marco Dell'Osa

    Hi!! Many thanks for your tips! It works perfect on HR626 to (same printed circuit)! I just replace the C65 capacitor of my monitor and it started working perfectly again.

  66. Jason Perez

    Thank you so much. I was stumped as to why my HR624’s were not working. I tried your method and screwed up a bit as I am a brute who has never soldered. However, my neighbor inquired what I was up to, I told him that I needed to do some desoldering. He told me to bring the monitor over to his garage. 30 minutes later, BOTH monitors have new capacitors and I am in bliss with that awesome sound flowing through my eardrums!!! Thank you once again!! DJ P Rock.

  67. Ray

    Help please. I changed out the capacitor and it didn’t work. Turned out to be that 1 of the 2 fuses was blown (checked 1 and missed the other). Changed the fuse out it worked but when i put it all back together and tested, got a horrible scratchy / radio static sound out of the speaker (like it was a radio tuned between stations). Resoldered, same. Swapped out for a new cap, then nothing, wouldn’t even switch on. Checked all the fuses, even the mains. I’m so mad at myself for not having seen the 2nd fuse and now i’m at a complete loss. Why won’t the speaker power up? 🙁

  68. Tim

    Thanks so much for this. I just fixed $3000 (3 pairs!) worth of speakers for $2.50 worth of capacitors.

  69. Barrett

    And here we are in 2017 with this article still providing MUCH appreciated wisdom and knowledge!

    I just ran across this article and will be attempting it tonight!
    SO EXCITED and HOPEFUL!!

  70. Tamas

    Hi guys. I have a 824mkII. The same method working for them?
    Thanks,

    1. Berni

      I’ve try this method with HR824 Mk2 … didn’t work in my case

  71. Jim

    Someone PLEASE tell me what power cord I need for these speakers? I’ve been searching forever. It’s the two pin one. I got a pair of these monitors really cheap from my local music store and assumed it would have the normal 3 prong plug. . It’s some weird 2 pin deal. The music store had a couple of two pin plugs but they didn’t fit HELP!! lol

    1. Ruvane

      I’m having the same problem. Can’t find the power plug anywhere. If you figure it out, please let me know !

    2. Hank

      the cord isnt special, its just missing the third plug for ground. you can use a standard power cable for a computer, it wont cause any problem at all. the additional ground is just not used on the 624/626 (which makes it a bit more like consumer audio equipment that way)
      but yes i have been using a 3-pin computer cable for years and it works perfectly fine

  72. eyal

    hi
    ive accidentally replaced the C64 capacitor with one that fits the C65 specs.
    now the speaker wont turn on.
    can anyone tell what capacitor specs are needed for the C64 capacitor ?

  73. James Zatopa

    Thanks for sharing this. 20 mins + $5 and I am back to listening to my monitors in stereo.

  74. bez23

    Much love to you for this information. You just saved me from having to buy replacement speakers with non-existent monies. Hopefully squeeze a few more years out of my beloved HR624s.

    1. Guy

      I have some hiss and crackling noise that just appeared in my hr 624 mk2 even with inputs unplug I”m 2 month past warranty I wonder if it could be the same thing anybody can tell me?

  75. Steveorino

    Works on HR626 also. I repaired two so far.

  76. MD

    Thanks for posting this fix… I just fixed one of two dead mackies HR624 today. Sadly to find both my drivers blown – anybody have one?

    AN ODE TO C65
    Oh blue cylinder
    small and vulnerable
    yet with a powerful role
    unable to hold charge any more
    so the chip amps sleep
    you have withered and died
    so I pluck you out and replace you afresh
    LEDs light and sounds reward
    oh little cap you betrayed me

  77. PD

    Wow. Thank you for writing this, and thanks to all the commenters providing insight to what works (in my case I have a HR626 to repair). Over 5 years later, this article is invaluable, and I can only imagine it will continue to be as these speakers gets older.

  78. Patrick

    Thanks so much for the article. I was wondering, where did people get the replacement 63 volt 4.7 uf electrolytic c65 capacitor?

  79. GH

    I also just ran this fix (successfully!) to one of my H264s. In my case it was only the C65 cap that had gone bad, not the fuses. THANK YOU so much for posting!

    1. GH

      Edit: I meant HR624… must have had video encoders on the brain today.

  80. Nicolas Nami

    You just saved me a lot of money. I replaced both of them, and both of the speakers work like the first day I’ve bought them.

    Currently, this is where you can buy the part on Amazon. It works perfectly.
    http://a.co/3PFgCDG

  81. Dave M

    Thank you so much for sharing this fix. I can also confirm this works on the HR624 MKII and the same C65 capacitor. Part sourced on Amazon.

  82. Scotty Huff

    I’ve had my hr624’s for… well… a LONG time. At least 15 years. I used this post to fix one several years ago, and just used it again tonight to fix the other. Thanks so much!

  83. Michael Doyle

    Thanks for sharing this. I successfully repaired one of my HR624s using this fix about a year ago and then my other one went bad this week. This time around unfortunately I may have applied too much heat for too long soldering the capacitor in and damaged it and now the red overload LED comes on continuously as soon as the AC IEC lead is connected. No sound either.
    I will try again with a more cautious approach while soldering as I have a few spare capacitors.
    Has anyone else experienced this issue?
    This YouTube video was also helpful for disassembly and capacitor replacement: https://www.youtube.com/watch?v=Zm4KxQ-zBaE&index=2&list=PLMa891XQwvAz-NyEzF6sB2KcWLAdZicvh&t=32s
    For anyone requiring the PDF schematic for the HR624 to get other component values the link is on this page as a reposted attachment: https://music-electronics-forum.com/showthread.php?t=30812

  84. Michael Doyle

    This fix worked for me a year ago on one HR624 then my other went bad and I must have overheated the C65 cap during installation. Now The red LED comes on solid when the AC is plugged in and no sound! Time to try again with more caution with regard to heat when soldering.
    I used this YouTube video which I found helpful in addition to this article: https://www.youtube.com/watch?v=Zm4KxQ-zBaE&index=2&list=PLMa891XQwvAz-NyEzF6sB2KcWLAdZicvh&t=32s
    I also found a webpage with an attachment download link for the factory schematic for those who are trying to find other component values: https://music-electronics-forum.com/showthread.php?t=30812
    Thanks again for this post!

  85. Banj Jackson

    nice one, I removed the 8 screws and soldered it from the back of the pcb, there is enough room without any further disassembly, a squirt of heatsink compound and hey presto all woking. I love these monitors.

    thanks for the info.

  86. tomko

    My problem is a bit different. The indicator light up front is on, but the volume is off. If I unplug the cable form the mix table and plug back in, I can usually get it on again. Now it’s off with no volume. do you think this is just a capacitor problem as well, or is the amp dead?

  87. Perry

    Based on your guide here I’ve done this repair on both of my 624’s now… the first one about 2-3 years ago and the 2nd one just now haha.

    btw the Torx driver to get the amp plate off is a T20 for those who do not know…

    Thanks again for this posting, saved me and many others a lot of trouble!

  88. Robin

    I am considering buying these speakers, but am uncertain now, knowing this fault. Does anyone know if a brand new set bought in 2021 will have the same flaw?

  89. Guy

    I’m about to do my second repair as well. First repair was 2 years ago and now the second monitor has failed. Mine are HR624s from probably 2003 or 2004. Thank you so much for posting this article and keeping it up!

  90. Scott

    Just replaced the same capacitor on a H624 Mk2. The guts are very similar but there are a few differences in the enclosure. To me, it’s worth disassembling it in order to get to the solder spots on the bottom of the board. Makes removal and soldering really easy. On youtube, there’s a decent video of someone replacing the same capacitor in the Mk1. He even has a link to the part you’ll need. I also recommend replacing the heat sync grease since you’ll be disturbing it when you disassemble the enclosure. I’ve never taken these enclosures apart and I have never replaced a capacitor. Just take a little time and you’ll be fine. Oh, and make sure you take pictures during the disassembly stage so you’ll have a good reminder of where everything goes when you’re putting it back together.

    1. Scott

      Follow up on my repaired monitor. I was swapping out cables the other day and when I plugged that speaker back in I have power but no sound. I’m ready for these to go on ebay.

  91. Steve

    Great article,

    Has anyone has problems with the controls on the back of the 624?
    Mine start to give problems like volume and frequency response changes/ instability.
    Turning the controls up and down and switching setting fixes the problems for a short while.
    Tried contactcleaner, barely gives improvement. Maybe the fluid doesn’t get to the core of the components sprayed from the outside.
    Any ideas?

    1. Jake

      Could be solder joints are dried out and not making proper contact with the board. A quick re-solder should do the trick.

      Thank you to the original creator of this article, it has helped many of us revive our speakers!

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