Hello there,
Does somebody have a schematic for 7I77 ?
I can't get a hold at somebody at Mesa, it's been a full month since I've sent multiples mail but with only 2 answers telling me they are too busy.
I would like to repair this card, but with no schematic it will be hard. I could do some retro engineering, but it would save me some time if someone have.
My first guess is a dead DSpic.
A quick look on the card:
Power side:
A step down regulator (A8499) is providing lower voltage (3.3V I guess) for the dspic, input multiplexer and output driver.
A self and a capacitor is filtering the lowered voltage (very similar to the datesheet)
Input side:
Multiplexer (74LV4051D) are connected on the dspic on one side, the other side is sensing the I/O field with some resistors to lower the voltage.
VCC for 74LV4051D is 7Vdc max.
Output side:
NCV7608 is the one (two in fact) who's doing output, controlled by a SPI bus from the DSPIC.
I will grab my voltmeter tomorrow to check the output of the voltage regulator.
There isn't a lot of components, it should be possible to fix this.