Behringer EP4000 gone pop x2

Cool, will fit 230v fans on all the time. Ball Bearing types too. I think all id need for heat protection is to turn on a buzzer when the heat sink is at 100c? or internal temps are 70c?
it can reach 42c here, so in the attic potential mid-60s? So, i may actually fit some more fans, or leave the top off and have a fan on the top and invert the lot?
Hmm
 
Top off will not put all the air on the heat sinks.
Alarm around 80 degrees, safe enough. should cut output stage power then.
Or a two stage scheme, fans on, amp off when temperature exceeded, back on when temperature drops 10 degrees, from the same power supply triggered by the projector.

Use a duct if needed to convey air flow.


How does that sound?
 
It is usually dried out hot melt..
As a precaution, remove the capacitor, scrape off the glue, and after checking the cap, put it back, or replace it.
The hot melt has been known to become conductive, not nice.

If it's hot melt, please do not scrape. Use isopropyl alcohol. If it's a silicone composite (eg Silastic brand 'goo') then you could try alcohol too, just to loosen the surface bond.

Top off will not put all the air on the heat sinks.
Alarm around 80 degrees, safe enough. should cut output stage power then.
Or a two stage scheme, fans on, amp off when temperature exceeded, back on when temperature drops 10 degrees, from the same power supply triggered by the projector.

Use a duct if needed to convey air flow.


How does that sound?

You can use a specially designed thermal cutout silicon package for this. They are self resetting switches.

I would not cut mains power straight up, I would instead just signal the switch mode supply for the amps to shutdown. That way, any amps that do have DSP's built in would go into protect ;)

In designs like the EP4K a duct is useless, as the heatsinks themselves are a duct. :)
 
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I meant a duct to vent, like a thick wall flexible tube used in A/c, the idea being to help the air flow, as he says the attic can get hot.
The unit is not brand new, and fooling around with the circuit is frankly risky, European electronics are not as well designed as Japanese and American.


What is the problem with scraping off hot melt, or cutting off using a very sharp blade?
 
Made a boo boo putting one amp back together, my probe for my MM slipped and shorted the emitter resistor to either the heatsink or one of the driver transistors or step MOSFET behind. It took out all the outputs and the one MOSFET and both drivers! :-(

I have fitted all new again and have restarted the attempt to set bias. But the mv over R106 remains static at 39mv whatever i do with vr6. I have checked vr6 and it was not good, so replaced it, but still no beans. (also checked r109 which seems ok) Where do i go next?