hey,
cheers for the replys.
yea i thought about subbing the nte part but was a little concerned i'd get too far of track... i.e. the nte is within 5% difference on some specs of the original, then the sub for the nte is within 5% of that. pretty soon i'd have a 100% different part
the part is for a power amp 'alesis ra 500' i'm over my head with it really, i have replaced most everything in the offending section even though they checked good. as per the advice on another forum months ago. (to ensure any damaged or overworked components were replaced just in case) the power transistors, diodes and 5watt resistors have been changed out for new ones.
th schem is available
electronics-diy.com/pdf/Alesis_RA500_Power_Amplifier.pdf easy but this is the section im looking at...
the part in question q115 and q116 (c4793) were the only parts i didnt replace.
i powered it up with a lamp in series because that and a dmm is pretty much my equipment.
still nothing on this channel.
from what i understand the jack was removed while it was on and shorted the output.
this section had burnt components. i thought this would have sorted it tho.
i would normally only want to replace the bad parts only but it seems like others could have been stressed at the time of failure and being a stereo amp i would have like to keep the channels closely matched.
maybe i could replace the right side channels transistor at this section too so they are both still the same.
so what are the qualities i should be focusing on for replacements?:
more current gain than original at least
equal c - e voltage
equal c - b voltage
equal or higher power dissipation
i cant figure out what the important numbers are for it in this position.