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Focusrite Liquid Saffire 56 Power Supply Unit Fix

If your interface doesn’t turn on or fully boot, the PSU may have failed.

A friend of mine brought over his Focusrite Liquid Saffire 56 audio interface to have me look at it. The unit wasn’t working. After turning on the power switch a few LEDs would blink and an internal relay would continually click, but it wouldn’t power on fully and wasn’t recognized by the computer.

We opened up the chassis and tried powering it on. WARNING: THIS IS REEEEAALLY DANGEROUS. DO NOT ATTEMPT UNLESS YOU KNOW WHAT YOU ARE DOING! We looked around to see if we could spot anything suspect. There were no obvious culprits like burn marks on the PCBs, blown fuses, or exploded/leaking capacitors.

Given the symptoms, I suspected that some of the electrolytic capacitors in the PSU were dried up or had vented—a common problem in gear that has aged a few years. Bad caps in the PSU could cause the unit to be under- or over-powered, which probably was causing the relay to keep tripping and preventing the main board from fully booting. After I pulled out the PSU I could more clearly see that the largest cap was bulged on top. That probably was the problem component.

Photo of the old PSU

Electrolytic capacitors go bad over time. At least one cap on this board had failed—perhaps others had failed too.

Since the interface was about a decade old and discontinued from manufacturing, it was essentially out of warranty. We decided to try fixing it ourselves.

Photo of the new PSU

The new PSU has a cool new look and maybe some better electrical engineering too.

I found a suitable replacement PSU sold by Full Compass. This replacement PSU doesn’t look the same as the original PSU that comes in the Liquid Saffire 56 and the Liquid Saffire 56 is not specifically listed as one of the compatible units, but it is in fact compatible. A Focusrite support representative confirmed that this PSU is the correct replacement.

So my friend ordered the PSU. A few days later it arrived and I swapped the old for the new. The interface fired right up and is working like new.

Photo of the interface after the repair

It’s working!

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EV ZLX Series Input Board

Locating a replacement input PCB board for the EV ZLX series speakers can be difficult. Here’s where I found the part I needed.

The back panel of an EV ZLX-12P

Both of the XLR combo inputs on the back of my EV ZLX-12P powered speaker were blown. The previous owner had connected an amplified signal into the line level input. In layman’s terms, that’s bad.

Everything on the PCB looked fine, but somewhere in the input board circuit something was fried. The 1/8″ stereo aux input still worked, which told me the amplifier board was still working correctly. So I simply needed to replace the input board.

Easy, right? Nope.

Trying to find just the input board and not the entire back of the amplifier was very tough. Most of the places I was finding online were in the UK. The price of superfluous parts plus international shipping was nearly the same price as buying a new speaker. It was hardly worth fixing.

That is, until I found a Canadian supplier that sells the input board separately. I found it buried in a Bosch parts list. In case you need the same part I did, here’s the contact information you need…

Taylor Electronic Services Inc.
2075 – 16th Ave. E.
Owen Sound, ON, N4K 5N3
Tel: (519) 371-7710
Toll Free: (888) 371-0779
Fax: (519) 371-0813

Ask them for this part…

Description: ZLX Input PCB Assy.
OEM Part #: F.01U.294.654
TES Part #: 12854
Price: $98.00 CDN / $76.00 USD
(price as of Oct. 2018)

This little thing is surprisingly hard to find.

This input board will fit both the ZLX-12P and ZLX-15P powered speakers. I’m not sure if it works with the ZLX-12BT and ZLX15BT models or not, but I would assume that there’s either a different input board or additional Bluetooth board for those models. This board is definitely not needed in the ZLX-12 and ZLX15 passive speaker models.

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FIX: Neumann KMS 105

Inconsistent audio signal from your KMS105? The fix might be really simple. Here’s how I fixed one.

My wife Katie Nelson and I both use Neumann KMS 105 condenser microphones for live performance. We love how the microphones sound and trust the Neumann brand.

The Problem

Recently Katie’s microphone was passing audio inconsistently. Sometimes it was normal, sometimes the output volume was quieter, and sometimes it would crackle as if the XLR cable was bad.

I called Sennheiser, the parent company of Neumann, to inquire about repairs. They connected me directly with a bench technician who kindly asked questions about the symptoms and then walked me through the fix. He correctly suspected that the hex screws holding the capsule to the internal printed circuit board (PCB) were loose. In fact, the capsule was completely disconnected from the PCB. I was surprised that the microphone worked at all considering there was almost no contact between the capsule and PCB.

PRO TIP: Microphones work best when the capsule is physically connected. #signalflow

The Fix

  1. Take out the machine screw on the side of the microphone that holds the XLR insert in place. There may be a small lock washer underneath the screw. Set them aside.
  2. Unscrew the basket (or grille, as people often refer to it).
  3. Slide off the black capsule cover screen.
  4. Very carefully pull on the capsule while simultaneously pushing on the XLR insert. WARNING: BE VERY CAREFUL WITH THIS STEP. THE PCB HAS A SERIES OF WAVY CUTS IN IT. TOO MUCH PUSHING OR PULLING CAN BREAK THE PCB. GO SLOW. GO EASY.
  5. Pull back the rubber ring around the brass capsule body. Remember the orientation of the ring in reference to the notch in the body.
  6. Confirm that spring is seated properly on the capsule center pin.
  7. Push the capsule body onto the PCB until fully seated. The hex screws should be positioned over the solder-tinned holes.
  8. While holding the capsule and PCB together in that position, use a 0.035″ (0.89mm) hex key to tighten down the tiny set screws.
  9. Replace the rubber ring. Make sure the orientation of the ring fits into the notch in the body.
  10. Carefully insert the assembly back into the body. Again, be very careful. You will likely need small pliers/grips/etc. to pull the XLR insert all the way into position while simultaneously pushing the capsule into the body.
  11. Tighten the screw through the body into the XLR insert.
  12. Slide the capsule cover screen onto the capsule.
  13. Screw the basket onto the body.
  14. Test the microphone. If you still are experiencing audio problems, contact Sennheiser for service.
Little parts are easy to break. Be especially careful with this section.
Affiliate Links

Disclaimer: The links to the hex key and microphone above are Amazon affiliate codes. By clicking through and purchasing, I receive a small kick back. Thank you for your support.

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How to Fix a JBL EON10 G2

So your JBL’s are rattling when you pick them up, eh? Getting that uneasy feeling about that clunky noise when you move them? If it’s the same unsettling noise I heard, then I have an easy fix for you. 1. Disconnect the speaker from all power sources.* 2. Place the speaker face down and open […]

March 28th, 2008 | Friends, Technology | , | Comments: 1

So your JBL’s are rattling when you pick them up, eh? Getting that uneasy feeling about that clunky noise when you move them? If it’s the same unsettling noise I heard, then I have an easy fix for you. 1. Disconnect the speaker from all power sources.* 2. Place the speaker face down and open up the shell by unscrewing all the screws around the outside edge. There’s like a million of them, so use a power drill with a long #2 phillips driver bit. 3. Lift the shell off and set it aside. Be careful not to lose any of the screws. 4. Locate the magnet coil and tighten the bolt that runs through the center.
5. Replace the shell. 6. Tighten all screws. 7. Enjoy your clunkless speakers. NOTE: I am NOT a licensed repairman, electrician, or lawyer. I have no idea if fixing this problem will void your warranty, so don’t blame me if/when JBL won’t service your speakers. Nor will I assume responsibility for you doing something stupid while dinking around with dangerous electronics. Make sure you unplug the speaker first and don’t touch anything inside. If you kill the speaker or yourself, I am not liable.

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