I have a C Audio - RA 3000.

And for no reason the Protect light keeps coming on, off, on, off at about 5 sec. intervals. Have checked around inside, and can not find any thing obvious.

Any ideas??????

Does the channel work at all (i.e give sound at any point) or does it remain silent from switch on?.

Does it clear / reset the fault if you disconnect the speaker from the "faulty" channel?

The light could be on the blink 1

Is the flashing of the light steady eg: EXACTLY 5 seconds between EVERY flash...or is it random(ish).

I've known of some amps (which I used to use via an agency) which had a two speed cooling fan in them. The Protect lights would blink on and off, IF the fans ever had to step up to double speed, as a sort of indication to say..."stop driving me so hard, or clean out all the air filters"...

If its just random...it could be a dry joint about to go...either on audio cables, or the connectors into/out of, the amp.

If its safe to do so, try running the amp with no speakers attached (check manual), this at least eliminates the amp-to-speaker cables, and the speakers themselves.

Hi Gary,

Speakers and cables checked and used on another amp - No Probs

Conect Speakers, switch on, sound on both channels for about 30 secs, protect comes on, goes off approx 5 to 10 secs, the longer the amp is on the spacing gets shorter, on / off approx 1 sec. then the protect stays on for about 30 secs and the whole cycle starts again.

When the protect comes on the fan slows slighty.

I assume it is a temp prob or component breakdown.

I have seen a "similar" fault, about 25 years ago on a Citronic amp. That was caused be the Q Current drifting out of parameters. I say similar because on the fault the whole amp stopped working.

I've looked at the circuit dia's, I can't see anything obvious there either.

IF all this starts happened from cold, in just 30 seconds, I doubt that its thermal related. Thermal issues shouldn't crop up until the amps been running (hard) for a good few minutes at least, if not hours...

I think its more likely to be either a short circuit being detected, or component failure.

Does your handbook (for the amps) mention what events could trigger a "protect" state. Some amps "check" half a dozen possible problems...Short circuits, speaker impedence issues (possibly down to blown drivers and blown crossover fuses etc), Amp temperature, amp fan failure, etc.... others light the protect light only in one or two of those events.

I borrowed an amp once that checked itself every 5 or 10 seconds to make sure all was OK with itself, and I had a green light flash whilst it was in this mode. This may not help at all but just my tuppence worth. If it hasn't helped or I am stating the obvoius please show me to the corner of the room.

Did you lose all sound whilst it was checking????

Go stand in the corner, now that reminds me of a joke

OK, had a chat with some techie type people.
I have a fault in the protection circuit, the amp it's self is OK

i used to have a similar prob with one of my old crests - in the autumn/winter when the garage was damp it used too always go in and out of protect mode - hairdryer in the fan for a few mins sorted it out - now i just have to keep it warm and its ok! fussy bugger!