MSefi.com read only forum (Jan.15,2018)

That was plan 'B'. My thought was that if the cap was blown, it would be shorting out the voltage regulator. Why test that one first? It's easier to lift one leg on the cap than to swap out U5. If nothing happens when you lift C17, then it likely is U5.

OK, i will replace U5 and report back ...

Ok, that makes a lot more sense. It sounds like the diodes are good to go; the 275mv between D11 and D13 is probably the Vf for D13. That leaves you with the question of 0v on either side of C17 and C22, and 0.2v coming out of U5.

If C17 is blown (and tant caps do fail - often spectacularly), then ...

Just looking at the V3 board schematic, and what you're describing is not only not 'normal', I'd go so far as to say 'not POSSIBLE'. You have 0v at the non-banded end of D10, and 12v at pin 1 of U5?! 12v on both sides of D12 at the same time you have 0v both sides of D13 is very hard to do, since ...

I am getting sick and tired of this, I just need to get my truck running by now. I have seriously been contemplating a carburetor.

Anyways, I purchased a brand new MS v3 mainboard kit with a MS1 CPU from DIYAutoTune because i was having so much trouble with my last one (accidently fried the CPU ...