I know facts about FF's switching PS... and therefore stabilty for common voltage drops. I think at first there was a red light at first when unit rebooted. Everything lasts less then some tenth of second.... Strange thing is, it is a very very rare event. FF800 ran for almost whole week and the only thing were some dropouts during test, when comp was heavily interrupted. I even pluged a "hard" starting vacuum cleaner on parallel power plug and switched it up and down several times. All ligths in room blinked a little during this. But nothing happened with FF800. I also plugged 2kw iron, the same, nothing happened on FF800. Vacuum cleaner is "inductive" load but not grounded. Iron is grounded but is not inductive.

Qestion is whether FF800 is suspectible to ground potential or as you said - faulty PS?

Some "older" grounded inductive electrical devices (HQ lamp starters for ex.) can produce short voltage fluctuations even on ground line during start or shut down. I don't have any of such devices at my place, but I can speak for myself only... not for my neighbours.

Simple comments:

- All FF800 have the same PS (there is no 20W and 30W difference)

- The PS is neither underrated nor does the unit get too hot

- Older FF's power supplies sometimes suffer from a capacitor problem (like many other devices too). This is easy to repair. Contact your local distributor for details.

We are working on the false TCO display, but basically it has zero meaning and effect as long as you don't set the clock source to (the not existing) TCO.

Hello Eki77!

I think I also had that kind of problems with my FF800 like you with the FF400. But I have no proof for that. I think in my case there is more than one problem involved. At first it was the faulty power supply of FF800 which died yesterday. As you said and I agree with that, problems are to be expected in case equipment is fed by different power sources in poorly desigend electrical network. But that kind of problem is quite difficult to solve in some cases. Even with quality power conditioner (Furman) or UPS unit it is impossible to fed entire sound system through it as taht requires a LOT of electrical power. And when you connet two devices you ground them together. If ground of one has different potential then another than there is some current drawn through which my interrupt FW communication in case of FF800 or FF400.

But in general, pro audio equipment should whitstand some deviation from "ideal" electrical (ground) network.

After some days of successful operation of the problematic FF800 I took it to my friend who works in a electro acoustical repair service. I told him about possible loose contact on the red wire from the power supply. He said that FF800 seems to be a very solid built and high quality piece of electronics with almost no chance of cold/loose contacts. He said that nowdays around 80% of device malfunctions he deals with, rely to switching power supply's capacitors. Those capacitor problems were allready mentioned in this forum many times. We opened the unit again and replaced only two small capacitors of the PSU as other capacitors were not available at that time. The unit started ok. But then I pulled the red wire again and device shut down and in a few moments up again.

There was indeed a loose contact in a white 4 wire conncetor on the red wire. We fixed that in a few moments. Problem solved. There were no capacitor problems involved.

When I ran the device for some days outside the rack, I saw it does not get very hot indeed. I take my words back.

dadgad251 wrote

I think this should be easy to prove with sine tone and record and compare if drifting !?

and thanks for the hint "kasaudio"

regards S-EH

dadgad251 wrote:

kasaudio, please check whether this has also solved the false TCO display phenomenon...

In two hours of operation of the "healed" FF800 I am not able to see the false TCO display anymore. I clicked to show the CP almost every 5 minutes. No TCO... On the second unit I own there was never false TCO shown. But I'm not 100% shure as I test for that for two hours only. Before all that I got the false TCO in a few minutes.

If there will be no false TCO's in the future, that obviously has something to do with the hardware. In that case I could easily believe that this has influence on actual music playback (especialy with let's say - 15kHz sine wave playback).

What I did was not only the repair of loose contact; I also replaced two small capacitors of the PSU (they are located in the middle of the PSU board). One of them (47uF/50V/105 deg. C) -> rated capacity of 47 uF had only 42 uF measured capacity and that is 10.6% less. That could have some influence, but there my knowledge stops. I did not measure the second capacitor. But simple digital multimeter is also something you can't really rely on.

Loose contact in a way it interrupted unit to shut down once during several hours period... go figure what was going on in electronic circuits at that moments...

I've made some sine wave tests whether false TCO has some influence on audio playback/record. I must say I found/heard no influence at all.

1) I checked my mainboared and it is also Rev 1.0.5 09/06. So there you go RME this could be a coincidence but I doubt it.

2) Can you please explain the sine wave test?. Must I generate a sine wave and then while it is playing back record it again? And then what?