Issue with Thermionic Deluxe (PCB getting 300 degrees hot)

joe99812

New member
Hello,
I am building a thermionic deluxe and it does not work. I've used my kitchen infrared thermometer and found that the upper right portion of the PCB (where the power rail runs) is getting around 300 degrees. This is only happening along approximately a centimeter or so of the rail, so I don't believe it is a short. The power wire itself remains cool, and the rest of the power rail (that leads from the power wire to this spot on the PCB) is a bit over 100 degrees, obviously substantially cooler.

My theory is that the rail wire is damaged and causing high resistance. I have measured the resistance from the power +9v power wire connecting to the board to the D5 diode and it looks normal, but I'm assuming that under load there is more resistance on this part of the rail and it cannot handle the amount of current. Does that theory make sense?

If so, can I bypass this rail? The only thing I see the rail connected to looking at the PCB diagram (https://docs.pedalpcb.com/project/PedalPCB-ThermionicDeluxe.pdf) is the D5 diode. So can I just run the power wire directly to the diode and bypass the rail?

Any other idea as to what is going on?

hot spot:
Thanks in advance!
 
This is my first high gain pedal.

Just got the pedal assembled and put in the case, that eliminated basically all of the humming. Guess I should have taken your advice and tested in the case, but I was getting tired of assembling and disassembling.

This thing is fucking awesome. Thank you SO much to everyone for the help, especially you Chuck. I have learned a lot from this. Looking forward to building more pedals (with the correct resistor values the first time around :)).
 
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