Toasted a germanium transistor... Should I keep the board?

[Sesh]

So I was making the Paul Trompetta Bone Machine (f*cking excellent and versatile pedal, btw) on vero.

It was working perfectly (functionality wise) in my test setup, but was humming quite loudly when idle (I tried other pedals and compared, it was way louder.) Also my guitar's volume knob added a deeper hum when I turned it just a little bit down.

The issue seemed to be related to the gain-knob somehow as grounding it improved it somewhat, but didn't fix it. So I wanted to make sure there wasn't a cold solder joint or an unintentional bridge. So I resoldered the lugs of the gain-knob and reflowed all the solder joints.

When I turned it on again, my germanium transistor - only the transistor - became super hot very fast. I quickly turned it off, but I guess the transistor is toast. Thankfully it was only a cheapo AC125.

My question is: What about the rest of the circuitboard and the components? Are caps and diodes for instance likely toast as well? Is it good practice to reuse it after such an issue or should I start all over? ANd what is likely the issue of the "hotness" (I know, overflow of current somehow, but what could make only the transistor hot??)

[antonis]

Have you found the cause for trasistor toasting..??

[bluebunny]

Can you post a schematic?  Then it will be clear how the transistor gets its feed of current.

[Rob Strand]

The schematic is a lot like the Jordan Boss Tone - Nashville version,
Q1 = silicon NPN, Q2 = germanium? PNP.  Few cap changes + tone control before diodes.

https://www.diystompboxes.com/smfforum/index.php?topic=48469.20

There's two versions of the Paul Trompetta Bone Machine. 

http://tagboardeffects.blogspot.com/2016/09/paul-trombetta-designs-bone-machine.html

I'll let you guys fill in the gaps.

This one is also similar,
https://www.madbeanpedals.com/forum/index.php?topic=20800.0

[Sesh]

The schematic is a lot like the Jordan Boss Tone - Nashville version,
Q1 = silicon NPN, Q2 = germanium? PNP.  Few cap changes + tone control before diodes.

https://www.diystompboxes.com/smfforum/index.php?topic=48469.20

There's two versions of the Paul Trompetta Bone Machine. 

http://tagboardeffects.blogspot.com/2016/09/paul-trombetta-designs-bone-machine.html

I'll let you guys fill in the gaps.

This one is also similar,
https://www.madbeanpedals.com/forum/index.php?topic=20800.0

Apologies for the lack of schematic!

It is as Rob Strand posted. I made the deluxe version with a switchable silicon transistor, but the germ trans was switched on - the silicon should be unharmed.

[iainpunk]

is there any chance you shorted both sides of the 18kOhm resistor connected to 9V?
that would explain the toasty tranny.

i have had a similar thing happen with a poweramp i was working on, a stray wire fell onto a resistor and shorted it, instantly toasting/killing a transistor (i was lucky it wasn't the power transistor)

cheers, Iain

[Sesh]

Fixed it!
Most likely a short, yes. There was tiny end of a lead looking like it was touching the row above it. Scored gently with a knife around the lines and remove excess some solder.