Weird thing with monitor

thomasw88

Been using a couple of Behringer 205d's for vocal monitors for gigs for years.

At a gig on Saturday one of them just started flashing orange light and no sound came out of it.       We run from  Aux out 1&2  on the desk into a dual 15 band EQ rack system and then out to the monitors themselves.

I plugged it all in yesterday and ran an mp3 player through the desk at various volumes for about 2 hours and both worked perfectly. 

Anyone have any ideas what could have caused this?  I'm assuming it might be borked and as they've lasted a good few years won't be the end of the world although I could do without buying a new one tbh

maltingsaudio

Expect the unit was overdriven and the flashing light was the limiter whinging then the unit went into protect. Did you turn it off then turn it back on on the gig? That should reset the protection which probably explains why it works today. Nb playing mp3 through the unit doesn’t represent the same thing as putting live vocals etc through it as the transients aren’t there.

thomasw88

maltingsaudio said:

Expect the unit was overdriven and the flashing light was the limiter whinging then the unit went into protect. Did you turn it off then turn it back on on the gig? That should reset the protection which probably explains why it works today. Nb playing mp3 through the unit doesn’t represent the same thing as putting live vocals etc through it as the transients aren’t there.

I think we did turn it off and then on again but the light was still flashing.  Didn't have time to fiddle with it at the time.  

I had a feeling it might be something like that.  Will try it next gig and see what happens.

cheers for the response.

Musicwolf

You need to check the 'system', not just the monitor.  If it's an overload / circuit protection kicking in then you need to ensure that the unit isn't receiving too hot a signal due to something going wrong elsewhere.

Danny1969

Was it a flashing power light ?

If it was then that can be a problem as it normally means the SMPS (power supply)  turns on, see's an abnormal load (bad capacitor) so turns off then turns on, see's abnormal load (bad capacitor) so turns off etc etc and so on and so on. 

When a SMPS  does this you will often find at times it will start up, the cap will polarize and stop leaking, other times from cold it won't . This is because the mains isn't a constant voltage, it goes from nothing to a peak voltage and then under nothing to a peak voltage. So the exact point of turning on makes a difference, not that you could time it being it's 50 times a second

If it is an overload fault then remove signal input, turn off unit and turn back on and all should be well but if it plays up with no signal applied then my money is on the above explanation 

thomasw88

Danny1969 said:

Was it a flashing power light ?

If it was then that can be a problem as it normally means the SMPS (power supply)  turns on, see's an abnormal load (bad capacitor) so turns off then turns on, see's abnormal load (bad capacitor) so turns off etc etc and so on and so on. 

When a SMPS  does this you will often find at times it will start up, the cap will polarize and stop leaking, other times from cold it won't . This is because the mains isn't a constant voltage, it goes from nothing to a peak voltage and then under nothing to a peak voltage. So the exact point of turning on makes a difference, not that you could time it being it's 50 times a second

If it is an overload fault then remove signal input, turn off unit and turn back on and all should be well but if it plays up with no signal applied then my money is on the above explanation 

That sounds likely.  Is this fixable?

Danny1969

thomasw88 said:

That sounds likely.  Is this fixable?

Well in around 80 % of the cases I see replacing all the caps the secondary side of the switching transistor will generally fix the fault. That can be £10 to £20 worth of caps depending on the values. Sometimes you can visually see a bad cap as the top will be bulging like this in a power supply I fixed in this Apogee studio convertor, see the bulge in the top of the bad caps I'm pointing at 



If the problem persists then start by looking for that, unfortunately they can go bad and show no visual signs at all in some case (some vent from the bottom) but it gives you a start at least