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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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