1 (edited by SonicExplorer 2022-05-29 04:12:55)

Topic: Help - Fireface 400 acting strange at power-up...

Hi Guys,

My Fireface 400 began acting strange at power-up and I'm wondering if anyone has ideas as to what could be going on...

About 5-10 seconds after power up there is a click followed by a strange static/interference sound that lasts a few seconds, then the sound stops and the 2 green preamp lights on the front flutter for about 5-10 seconds.  Everything behaves normal after that.

Any idea what this may be?  Some kind of initiation problem, or is the FF400 starting to go bad....or maybe the external power adapter?

Could really use some guidance on this....anyone experienced this before or heard of such a problem??

Thanks,

    Sonic

2

Re: Help - Fireface 400 acting strange at power-up...

I would try a different power supply first.

Regards
Matthias Carstens
RME

3 (edited by SonicExplorer 2022-12-07 00:25:06)

Re: Help - Fireface 400 acting strange at power-up...

Update: This problem has worsened. It now takes the FF400 almost 3 minutes after power-on for the static to subside.  After which the device functions ok.  It doesn't seem likely to me this behavior would be an external power supply issue so I have been hesitant to purchase a new one.  Upon Googling the issue I ran across a post on an audio forum that makes a lot more sense to me: It states the issue may be on the portion of the power supply INSIDE the FF400. (Oddly enough, RME never once mentioned this in my emails or phone calls). See text below.  In light of this information, anyone have further insight or guidance...???

Sonic

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"The PSU inside Fireface 400 consist of two switch mode regulators / converters. First is LM2595 5V and the 9 to 19 V from the adapter is converted down to 5. This is the same point where the 5V from the FireWire port connects and where the switch sits. There is another switch mode LM2588 12 which makes the +-12V to feed the audio circuitry and on the lower board there are two more regulators which make 3.3V and 5V for AD and DA converters.

The first converter has quite a demand on super high quality electrolytic capacitors and RME didn't follow the guideline in the datasheet here. It strictly requires special and very expensive capacitors capable of handling substantial ripple current at the nice toasty temperature inside the Fireface400. RME opted for high quality condensers but not the special kind required for this position and therefore they fail after certain number of hours in use. They are labeled C512 and C513 on the board.
When these are replaced it will work on the adapter again unless it killed the LM2595 which may need to be replaced as well.

It's parts for just a few $$ but it requires somebody skilled with multi layer PCB SMD soldering / desoldering. It is essential to use a preheater to avoid damage to the PCB"
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I've soldered plenty of typical parts in/out of conventional circuit boards, but not SMD or multi-layer boards...am unsure what specials skills or tools are needed.  Or, since I'm the original owner does anyone know if RME might offer a replacement board for a reasonable price before the device stops working altogether?