The No.1 Website for Pro Audio
 Search This Thread  Search This Forum  Search Reviews  Search Gear Database  Search Gear for sale  Search Gearslutz Go Advanced
Moog Voyager: power supply caps leaking or something else? (pics included) Effects Pedals, Units & Accessories
Old 12th February 2018
  #1
Lives for gear
 
Praxisaxis's Avatar
 

Thread Starter
Moog Voyager: power supply caps leaking or something else? (pics included)

Hey All,

My (usually) 100% reliable Moog Voyager has been intermittently shutting down after powering up. It's not a clean shutdown . . . it kinda staggers out; sometimes rebooting or sometimes appearing to crash.

My first thought was "capacitors in the power supply" as I've had similar problems with other gear previously (and mended accordingly!). I know that if I am able to replace these and it solves the problem, I can save a fair bit of money, and it's not a difficult job.

So I opened it up, and had a look at the power supply. Indeed, there appears to be a lot of crumbly discharge at least around the big capacitor. It's either leaked out of that, or perhaps out of some other component, or several. . . But there isn't the normal swelling I notice when a cap is buggered. I'm hoping you can have a look at these photos and let me know what you think.

Basically, is that crumbly stuff coming out of the caps, or could it be another problem?

N.b. the other insides look fine on a visual inspection (remember, the only problem seems to be intermittent shutting down - when it's on it appears to work fine).

Also, apart from simply replacing the capacitors, can you suggest the easiest way to test them (without killing myself)?

Moog Voyager: power supply caps leaking or something else?  (pics included)-capacitor-2.jpg

Moog Voyager: power supply caps leaking or something else?  (pics included)-capacitor.jpg
Attached Thumbnails
Moog Voyager: power supply caps leaking or something else?  (pics included)-capacitor.jpg   Moog Voyager: power supply caps leaking or something else?  (pics included)-capacitor-2.jpg  
Old 12th February 2018
  #2
Lives for gear
 
acreil's Avatar
 

I don't know what the crumbly stuff is, but it looks like at least that one cap is leaking. And the symptoms are consistent with capacitor failure in a switching power supply. You'll want to wash the electrolyte off the board too. I don't think there's much point in testing them since it's cheap and easy to just replace the larger ones. Also, if you don't want to die, don't touch it while it's on; everything on the primary side is at mains voltage. The capacitors (especially the largest one) will retain some charge after it's switched off. Discharge it before touching anything if it's recently been powered on. There's probably a bleeder resistor across it to slowly drain the charge away, but short the pins just in case.
Old 12th February 2018
  #3
Lives for gear
 
Praxisaxis's Avatar
 

Thread Starter
Quote:
Originally Posted by acreil View Post
I don't know what the crumbly stuff is, but it looks like at least that one cap is leaking. And the symptoms are consistent with capacitor failure in a switching power supply. You'll want to wash the electrolyte off the board too. I don't think there's much point in testing them since it's cheap and easy to just replace the larger ones. Also, if you don't want to die, don't touch it while it's on; everything on the primary side is at mains voltage. The capacitors (especially the largest one) will retain some charge after it's switched off. Discharge it before touching anything if it's recently been powered on. There's probably a bleeder resistor across it to slowly drain the charge away, but short the pins just in case.
Got it, thanks. Yep, I do know not to mess with mains All my servicing will be with the power off. I guess I'll just replace some, see if it works, and if not maybe I'll just order a new power supply.
Old 12th February 2018
  #4
Lives for gear
 
Praxisaxis's Avatar
 

Thread Starter
Quote:
Originally Posted by acreil View Post
I don't know what the crumbly stuff is, but it looks like at least that one cap is leaking. And the symptoms are consistent with capacitor failure in a switching power supply. You'll want to wash the electrolyte off the board too. I don't think there's much point in testing them since it's cheap and easy to just replace the larger ones. Also, if you don't want to die, don't touch it while it's on; everything on the primary side is at mains voltage. The capacitors (especially the largest one) will retain some charge after it's switched off. Discharge it before touching anything if it's recently been powered on. There's probably a bleeder resistor across it to slowly drain the charge away, but short the pins just in case.
By the way, when you say "wash it" how would you suggest doing this? I could blow some of it out with an air gun. But what should I wash it with?
Old 12th February 2018
  #5
Lives for gear
 
acreil's Avatar
 

Quote:
Originally Posted by Praxisaxis View Post
By the way, when you say "wash it" how would you suggest doing this? I could blow some of it out with an air gun. But what should I wash it with?
Water should be okay in most cases (although probably not where there are trimpots/potentiometers or high impedance circuits).

Also it's probably just the largest capacitor that's failing.
Old 12th February 2018
  #6
Lives for gear
 
Praxisaxis's Avatar
 

Thread Starter
Quote:
Originally Posted by acreil View Post
Water should be okay in most cases (although probably not where there are trimpots/potentiometers or high impedance circuits).

Also it's probably just the largest capacitor that's failing.
Thanks Acreil. Yep the big one is very easy to remove and replace, so I'll try that. With some luck that's all it'll be. Worst case scenario, I have to order a power supply.
Old 12th February 2018
  #7
Lives for gear
 
Praxisaxis's Avatar
 

Thread Starter
Looks like it's fixed. I changed that big fat boy. Now there is a tall one in there, so I couldn't mount it directly on the board - had to wire it in. But it's been powered up for over an hour with no issues.
Old 12th February 2018
  #8
Lives for gear
 
acreil's Avatar
 

Quote:
Originally Posted by Praxisaxis View Post
Looks like it's fixed. I changed that big fat boy. Now there is a tall one in there, so I couldn't mount it directly on the board - had to wire it in. But it's been powered up for over an hour with no issues.
Be careful that the leads don't short to anything, there's about 300V across them.
Old 12th February 2018
  #9
Lives for gear
 
Praxisaxis's Avatar
 

Thread Starter
Quote:
Originally Posted by acreil View Post
Be careful that the leads don't short to anything, there's about 300V across them.
Noted . I put them in proper, with heat shrink over the joins, no exposed metal.
Old 12th February 2018
  #10
Lives for gear
 

That looks like electrolyte leaking from the caps.

you should use zero residue contact cleaner (denatured alcohol) and a brush to clean it up but you will need to replace the caps too.
Some caps will leak before they short out completely and explode. You want to change them out before that happens and don't run the unit till you do, otherwise you're going to have to do allot more work then changing out a couple or $3 caps. Be sure you mark the polarity before pulling the old ones out. Most PCB boards should be marked positive and negative buts its better to be safe then sorry.
Old 13th February 2018
  #11
Lives for gear
 
Praxisaxis's Avatar
 

Thread Starter
Quote:
Originally Posted by wrgkmc View Post
That looks like electrolyte leaking from the caps.

you should use zero residue contact cleaner (denatured alcohol) and a brush to clean it up but you will need to replace the caps too.
Some caps will leak before they short out completely and explode. You want to change them out before that happens and don't run the unit till you do, otherwise you're going to have to do allot more work then changing out a couple or $3 caps. Be sure you mark the polarity before pulling the old ones out. Most PCB boards should be marked positive and negative buts its better to be safe then sorry.
I changed a couple of the suspect looking ones, and the Voyager is functioning well again. Do you reckon I should do all of them?
Old 13th February 2018
  #12
Lives for gear
 
acreil's Avatar
 

Quote:
Originally Posted by Praxisaxis View Post
I changed a couple of the suspect looking ones, and the Voyager is functioning well again. Do you reckon I should do all of them?
The big one is the most highly stressed component by far. Replacing the others probably won't hurt anything, but I doubt it's really necessary. I recently repaired some LCD monitors and just replaced all the large-ish electrolytic capacitors without bothering to test them. But once I had removed them, I found that the ones that weren't obviously bad (i.e. swollen or leaking) tested fine.
Old 14th February 2018
  #13
Lives for gear
 
Praxisaxis's Avatar
 

Thread Starter
Quote:
Originally Posted by acreil View Post
The big one is the most highly stressed component by far. Replacing the others probably won't hurt anything, but I doubt it's really necessary. I recently repaired some LCD monitors and just replaced all the large-ish electrolytic capacitors without bothering to test them. But once I had removed them, I found that the ones that weren't obviously bad (i.e. swollen or leaking) tested fine.
I think I will leave it for now and see how it goes. I left it powered on for about 24 hours without an issue.
Old 14th February 2018
  #14
Lives for gear
 

That power supply seems more Mean than Well.

Statistically speaking, primary-switched PSUs issues are among the most common equipment failure causes. Sadly many equipment manufacturers rely on 3rd part PSU boards so often the PSU is of lower quality than the other electronics.
Old 1 week ago
  #15
Lives for gear
 
Praxisaxis's Avatar
 

Thread Starter
I have to reopen this baby!!
Right, so, I had replaced the big 100uF / 400v electrolytic capacitor on the power supply, visible (not circled) in the images above.

The instrument ran well for about 6 months, but here I am back again . The Voyager started exhibiting the same problems (power cut outs etc) a few days back. Anyway, I simply replaced that same capacitor again, and again that seemed to fix the problem. So I'm ok for now, but curious. . .

But out of curiosity, I wonder what that original capacitor was exactly? I have lost it unfortunately, but I know that they vary in tolerances and quality. I wonder if the one I bought from my local electronics shop is really the sort I should be using. So my question for you peeps is, do you recognise the specific make of the capacitor from the images here (ignore the red circles this time, I mean the biggest fattest one, which is black with some white and red on the label)? I know it's 100uF / 400v, but wondering if I should be concerned for its other specs.

Any ideas?








Last edited by Praxisaxis; 1 week ago at 07:10 AM..
Old 1 week ago
  #16
Gear Addict
 

Hello

As already stated this is a OEM meanwell SMPS, probably PD-45 or PS-45, this is a 15 bucks part... you better buy a new one than replacing capacitor for the second time.

side note: the electrolyte dispersion over the psu look strange to me if coming only from the big capacitor, so other capacitor may have issue too OR you may have a capacitor or a battery at a PCB over the PSU that have issue too ?

Best
Zam
Old 1 week ago
  #17
Gear Maniac
 

Switchmode power supplies often require capacitors with certain characteristics that may or may not be satisfied by a general-purpose capacitor. Using a general-purpose capacitor in these applications can result in a shorter lifetime than you'd normally expect out of the cap. For example, depending on the circuit topology, you may need a low-equivalent series resistance (low-ESR) or high ripple current withstanding (to avoid excessive internal heating) part.

The big cap is a Nichicon, but from the wrapper, it looks like it was private-labelled for Mean Well so it may be impossible to tell if it's from one of their standard capacitor series. If it has a series designation on it somewhere (a combination of letters, usually), then you can make an educated guess about a replacement by looking up whether that series has any special properties.

I'd probably just replace the power supply. They're generally pretty inexpensive, and with the problems you've had with this one, it would be cheap insurance.
Topic:
Post Reply

Welcome to the Gearslutz Pro Audio Community!

Registration benefits include:
  • The ability to reply to and create new discussions
  • Access to members-only giveaways & competitions
  • Interact with VIP industry experts in our guest Q&As
  • Access to members-only sub forum discussions
  • Access to members-only Chat Room
  • Get INSTANT ACCESS to the world's best private pro audio Classifieds for only USD $20/year
  • Promote your eBay auctions and Reverb.com listings for free
  • Remove this message!
You need an account to post a reply. Create a username and password below and an account will be created and your post entered.


 
 
Slide to join now Processing…
Thread Tools
Search this Thread
Search this Thread:

Advanced Search
Forum Jump
Forum Jump