Destroyed R33

[Colonel_Sanders]

Hey guys, burnt out R33. I installed D2 backwards, when I pulled it out from the PCB board half snapped off, so at the advice of the local component store which didn't stock 1n4002's, I replaced it with a 1N4004 and powered it up.
Then R33 caught fire.

Is it simply the diode? Or does it sound like something more sinister...

Cheers,
C_S

[tpryan]

It's not the diode, a 1N4004 is a perfectly good replacement in this application. You probably swapped Q1 and Q2. It's also possible C16 is in backwards.

[Colonel_Sanders]

Legend! You're totally right. And not a minute too soon, session in 12 hours . Extracting and replacing now... Will let you know.

[Colonel_Sanders]

Swapped Q1 and Q2. The resistor stays but Q1 starts to get really hot and smokes. Could placing them in the wrong order to begin with have damaged them? Unfortunately the only electronics store that stocks MPSA56's isn't open till Monday...

Thanks,
C_S

[Colonel_Sanders]

Nevermind. I was tacking them to the back of the PCB as a temporary fix, got them the wrong way round. Just biased the A12 and Neve w/o blown cap. Next to see if they pass audio!

Much thanks!
C_S

[Colonel_Sanders]

Sweet sweet audio. Sleep time. Thanks again!