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Mackie 1220 Power Supply problem
Old 27th June 2012
  #1
Mackie 1220 Power Supply problem

Alright this might be a completely stupid question but I have a Mackie 1220 that has a major power supply issue. The lights flicker- no sound can pass thru basically worthless. The fix is like $400 which i could buy a used one for that. My question is would it be possible or even feasible to pull the eq sections (which i think sound pretty good) and the preamps and wire them as individual channelstrips/eq/ preamps, whatever or is it hopeless. Its a pretty nice sounding unit and I just hate to throw it out.
Old 27th June 2012
  #2
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LeeYoo's Avatar
 

Find another repairman.
$400.00 (US?) is a lot of money for a (40watt) supply repair.
Could be just a few caps in the supply.
Leo..
Old 27th June 2012
  #3
That was the price from Mackie a year ago.
Old 27th June 2012
  #4
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LeeYoo's Avatar
 

Did you already open it.
A wise old tech told me once that you can find 50% of the problems with your eyes and your nose.
Look for bulging capacitor tops, and burned IC's.
Like this.. http://homerecording.com/bbs/special...1220-a-328053/
Post pictures.
Leo..
Old 27th June 2012
  #5
Yeah i've opened it up a few months ago but don't remember seeing anything burnt. I'll post pics sometime today. Good idea. Thanks for the help.
Old 27th June 2012
  #6
jrp
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the psu is build in?
It might be easy to take it out and build a new one. Those strips will need a psu in any case, might just leave them in their enclosure and just make sure the get the power they need.
Old 27th June 2012
  #7
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Hi
There are a few 'issues' with this:
400 does sound a 'bit steep' but may reasonably represent the cost of a new power supply section and someone to fit it.
Attempting to 'degrade' the efforts of techs who would know how to fix things by refusing to pay practicable rates (like enough to cover time, experience, heating, lighting and so on) is simply making things worse. Knowing that it is a 2 Dollar part is not the same as knowing exactly where to put it, and take responsibility for your continued safety afterwards.
Having gear manufactured in countries where labour rates are ridiculously low 'skews' the market leading to unjustifiable expectations for things like repair costs where a 'tech' is paying the same rates and costs as you, not being paid half a bowl of rice a week.
Here if you washing machine breaks down, it can cost 50 - 60 to get someone to look at it, then more depending on the bits and time necessary. You can get a new machine with warranty for 250 - 300.
It's the 'disposable society'.
Matt S
Old 27th June 2012
  #8
Here is the power supply section
Attached Thumbnails
Mackie 1220 Power Supply problem-power-supply-1.jpg   Mackie 1220 Power Supply problem-power-supply-2.jpg   Mackie 1220 Power Supply problem-power-supply-3.jpg   Mackie 1220 Power Supply problem-power-supply-4.jpg  
Old 27th June 2012
  #9
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Hi
That supply is a 'switchmode' design so it must ALL work prefectly otherwise there is a good chance that if you only replace the 'obvious' faulty bits it may be 'weakened' and simply fail again now or soon. Faultfinding is possible but inherently dangerous to both you and it, as there are many volts available and you can't 'ease into it gently'.
You COULD make up an external supply and feed it into the remaining desk, the 'favourite' being a Power One 'dual rail' supply and another for phantom it you want it. A supply plus a box would probably get you to best part of 200 Dollars if you do it 'nicely'.
Matt S
Old 27th June 2012
  #10
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a 1220 without PS might be considered an improvement by some.

OK seriously switching supplies generally don't use a lot of components, so if you can identify and source the replacement switching PS IC, and perhaps a switching FET and or diode, you should be able to repair it and get change from $400, if the coil/transformer is bad that could be more expensive to source.

This is generally well above a simple beginner DIY project, but swapping out switcher parts is not that much different from swapping out linear analog parts, solder is solder. If this is switching down from the hot mains supply that adds another degree of difficulty and danger for the novice. (do not kill yourself for a 1220).

For $400 maybe find some adventurous junior repair tech and let him have at it, what's the worst that could happen.? the insurance company has already totaled it.

JR
Old 27th June 2012
  #11
[QUOTE=JohnRoberts;8017101]a 1220 without PS might be considered an improvement by some.

That's true. I've since moved on to better things, but this has just been sitting around for 2 years now and i've decided to do something with it. I do really like the eq section tho. Very useable and thats why I started this thread in hopes I could pull those sections and use them.

I'm very much a noob when it comes to the internals of these things. I can solder and read schematics to a certain extent, and I'm definitely not willing to lose my life over this thing.
Old 27th June 2012
  #12
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Hi.
The power supply might be ok.
I see no burnt parts or bulging caps.
You say, the lights flicker.
Maybe the supply is in protection mode because of a short somewhere.
Did you already feel every IC if there is one heating up.
Leo..
Old 28th June 2012
  #13
Quote:
Originally Posted by LeeYoo View Post
Hi.
The power supply might be ok.
I see no burnt parts or bulging caps.
You say, the lights flicker.
Maybe the supply is in protection mode because of a short somewhere.
Did you already feel every IC if there is one heating up.
Leo..
Nah, I said screw it and decided to take it to a local repair shop today to see if they could diagnose the problem and depending on the price fix it. Thanks for all the help guys!
Old 12th August 2017
  #14
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I have repaired a couple of these power supplies. It is a lot of work to take them apart, but I have found out that capacitor C9 is the one that usually fails. It may take replacement of only that one part which will have it working again.
Old 18th March 2019
  #15
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Quote:
Originally Posted by bseabrook View Post
I have repaired a couple of these power supplies. It is a lot of work to take them apart, but I have found out that capacitor C9 is the one that usually fails. It may take replacement of only that one part which will have it working again.
Very old thread but bseabrook is dead on. I opened mine, a recent model, and even though C9 looks normal, but after desoldering it out of the ps board, it is confirmed DEAD. Genius.
Thanks a lot.
dan
Old 24th March 2019
  #16
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I was glad to find several references online to replacing C9 in a Mackie power supply when I had the flashing lights problem on my ProFX12, which uses a version of the same power supply that is in the small Onyx mixers. I did the repair yesterday using a 10uF cap with better specs (Nichicon, 63 volt, 105 degrees C, 10,000 hours). I ran it with signal for five hours yesterday, so far so good!
Old 24th March 2019
  #17
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Well, after letting it sit unplugged overnight I fired up today and got all the flashing lights again, so it seems that replacing just C9 was not the magic solution I hoped for, too bad. I may try living with it a while and see how unstable it is before I do any more on it. It does stop flashing if I whack it on the side, then seems to be OK. I'm going to leave it on for several more hours today and see how it does.
Old 27th March 2019
  #18
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Quote:
Originally Posted by Bluelick View Post
It does stop flashing if I whack it on the side, then seems to be OK. I'm going to leave it on for several more hours today and see how it does.
That is the sign of poor solder joints or burnt pins on molex connections.
Old 28th March 2019
  #19
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Richard Crowley's Avatar
Considering how ubiquitous the smaller Mackie mixers are, it is rather surprising that parts like power supply modules seem so rare on the secondary market. You would think they would be a dime a dozen. Maytbe they don't fail all that often? Maybe people just toss the whole thing as "disposable" without trying to "part-it-out"?
Old 28th March 2019
  #20
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I would push parts mounted on the board with a drumstick or chop stick to see if you make it flake out and re-solder that area. Wiggle wire harnesses too. Like I said. Its most likely a bad solder joint or one of those cables has a bad connection.
Old 28th March 2019
  #21
Gear Maniac
 

I bought the C9 cap in question, according to Bseabrook, and they arrived yesterday.
It was a 10 uf and 50 Volts.
Soldered it back on, and the Mackie ProFX8 works now.
Thank you so much Bseabrook.
dan le
Old 3rd April 2019
  #22
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3 days now and it is still going strong.
Thanks again Bseabrook.
dan
Old 16th May 2020
  #23
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I now have this problem on my pro fx8 and have replaced c9 like for like but still the power led just flashes really fast like twice a second any more suggestions welcome
Old 20th June 2020
  #24
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Quote:
Originally Posted by 3simplerulez View Post
I now have this problem on my pro fx8 and have replaced c9 like for like but still the power led just flashes really fast like twice a second any more suggestions welcome
I'm in the same boat, c9 didn't do the trick for me, I'll be replacing other capacitors soon. I'll probably replace all of the 4.7uf capacitors first, and see how it acts after I do that.
Old 28th June 2020
  #25
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Quote:
Originally Posted by CaptainAaron View Post
I'm in the same boat, c9 didn't do the trick for me, I'll be replacing other capacitors soon. I'll probably replace all of the 4.7uf capacitors first, and see how it acts after I do that.
Except of the capacitance (reffering on the electrolytic caps) another parameter that matters seriously is ESR (the resistance that capacitor relativelly of the frequency)!!!

Offten, I have seen capacitors during the measurement of capacitance to do not show a serious deviation of them value! But after a ESR measurement I realized that they was closely to be dead (low ESR value)!

All low capacitance electrolytic caps after a long time of use are suspected!
Certainly the quality is another point!

Fow a device that have been working for years, the best movement is to replace ALL of the electrolytic capacitors. Especially when I meet low capacitance/voltage caps I replace them with Tantalium caps!

Greetings from Athens/Greece!
Old 20th July 2020
  #26
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iv'e repaired two of the FX Pro Mackie mixers with the symptoms described, and on both occasions it was one of the diodes, I replaced both just to be sure, not had them back in the shop so I guess problem solved.
Hope this helps, Bob
Old 21st July 2020
  #27
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Quote:
Originally Posted by 3simplerulez View Post
I now have this problem on my pro fx8 and have replaced c9 like for like but still the power led just flashes really fast like twice a second any more suggestions welcome
I finally got around to replacing the other small capacitors on my power supply board for my Mackie onyx 1220, they weren't all 4.7uf like I posted a month ago. I'm no expert at soldering or troubleshooting electronics, but I fixed it and now I feel like I can do anything!!! Hopefully it'll stay working now. I'm glad Mackie provides the schematics for most of their equipment on their website, proved useful.

If I were you, I'd do what BobWells suggested first, check it, and if it still doesn't work, replace the smaller capacitors first, check it again, then replace the medium ones, check it, then replace the larger ones.

Like I said, I'm no expert though! Good luck!
Old 29th July 2020
  #28
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Richard Crowley's Avatar
Widespread, "systemic" problems as presented by the OP are more likely to be caused by issues with the larger capacitors.
Replacing a bunch of small capacitors could be a waste of time and $$, and present many opportunities to screw something up.
But congratulations on your beginner's luck. :-)
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