us Failure?

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natesully
MegaSquirt Newbie
Posts: 32
Joined: Mon Jul 25, 2005 8:13 pm

us Failure?

Post by natesully »

My first experience with Microsquirt did not go too well. I was helping my friendly local FSAE team with their Aprilla bike engine, when the spark outputs became stuck on after we tried cranking the engine over. This was with 2.88i firmware. The coils smoked, and us made a terrible smell as the PCB gave off nasty black stuff.

I have absolutely no clue why this happened. We loaded some settings from an msq (with inverted trigger enabled, I checked), rebooted, and started cranking. It was working 100% the previous night. I then played with a scope and noticed that MS is not issuing spark commands- the pin 1 on each VB921 is stuck at 5/0V when we switch to and from inverted output. Everything else behaves normally. I even put the Extra firmware on to use the output test mode, to no avail. The spark drivers also acted funny, sometimes one being on and the other off at 0 RPM. Everything but the spark works 100%. I may have misread the scope, but it seems the problem is with the MCU, the spark drivers work fine and flow current when on.

Any ideas? Did I fry the MCU somehow?
95 Miata M-Edition, GT28 Turbo
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