Kind of an odd issue. I have been running a DIYPNP in my supercharged Miata for about 4 years. Many trouble free miles.

However, last week I went to start the car and it ran then died after 4 seconds. After doing some diagnosis, I ended up pulling the computer to find that the 5v power regulator LM7805C had burned up.

Not sure why exactly that would have happened. Is there some common wiring mistake that shows up 4 years later? Any ideas would be greatly appropriated. Thanks

 

Those are supposed to be short-circuit proof. Is it burned like a little piece of charcoal?

 

 

Only one leg seems to be burnt, but burnt it is.

 

@ReplaceDisplace

Did you get it fixed with a new transistor? All working well again?

Mine has burnt the same part of the board, but not the transistor - the 30A fuel injection fuse is blowing every 5 minutes.

Did you find any other issues which may have caused this?