I'm working on an crown CE2000A amplifier. The schematic calls this burnt component a "triac driver sbs bv thresh" and on its twin (in the non shorted channel) its only labeled "08d 25". This is in the protection circuit of the amplifier which unloads the outputs if there is a problem. The triac was also vaporized. One of the output transistors was shorted so I am assuming that the outputs were shorted or the load was overdriven. A smd resistor on the output transistor was also crispy (output transistors are hefty mj21194's 24 of them in fact) this is a serious amplifier and would be nice to get fixed. Does anyone know anything about these triac drivers? I need to find one that will work in the application, a direct replacement would be nice, if anyone is familiar with them and can decode that cryptic description.

Robert

 

If it is a two-leaded device, it is probably a diac or SBS (Silicon Bilateral Switch).

http://en.wikipedia.org/wiki/DIAC

 

After more research I came across the product number for this MBS4993 and I cant find this part number. This is a 3 leaded device btw. But I still cant find it.

Robert

 

if u need the chip detail click the following link
http://www.digchips.com/datasheets/part_details.php?id=636055&part-number=MBS4993