Here is a set of advice I have found online that I have distilled into some basic steps if things go off track or, at worst the magic smoke escapes!

1. Check the power headers for shorts. Put the multimeter into continuity (beep) mode and check the Eurorack power pin headers:

   Touch -12V pins and the GND pins?	NO BEEP
   Touch the +12V pins and the GND pins?	NO BEEP
   Touch the +12V and the -12V pins?	NO BEEP

2. Check the diodes in line for downstream shorts:

   Touch the anode(+, no stripe) of the diode connected to -12V and GND	NO BEEP
   Touch the anode(+, no stripe) of the -12V diode and the cathode(-, stripe) of +12V	NO BEEP

   If you are not sure which is the -12V diode connect the cathode (-, stripe) to -12V and it will beep. NB If there are 10R resistors or diodes in series on the power rails check for shorts from there not the pins.

3. Check IC orientations.
4. Double check the orientation of diodes, capacitors, transistors, V regulators, V references.
5. Double, double check those transistors, they are NOT consistent!
6. Check all jack sockets and sleeves are grounded.
7. Check all of the values used for components are correct.
8. For ICs that get hot: a) Is it oriented correctly? b) Are the correct voltages connected to it, +5V, +12V, -12V? c) Check the for non-power pins shorted to +/-12V where it is not supposed to be. d) As a last resort sip the chip out be be aware this could just fry the replacement.
9. Check all grounds pins, and ground vias connect to the power in GND.
10. Check continuity all of the traces to make sure they are not broken.
11. Check traces do not short to near by traces.
12. Check for shorts between pins, dry solder, bad joints.

If things did work but now they don't this is more of a repair process and some basic steps are:

1. Test and replicate the fault repeatedly to provide a baseline for the error.
2. Search for a block diagram of what is going on or create one. Check the schematic or create one and map this thru. Check you can follow power through the schematic and that it is going thru the board.