Scored this guy non functional on ebay and figured it could fix it up. Dead on arrival. Pulled the thing apart, checked the polarity, hooked up bench power. Power? Board is getting power but I'm only getting a trickle of power (<0.2V) out to any of the main board or to the FPGA. Looks like one of the components is cooked on the power board...see attached
Current plan is to replace the component - but I went through and ID'd most of the components (to the best of my ability, mistakes possible) to try and understand the workings. Can anyone help me understand how this board might be regulating power - and if something else might have caused that Schmitt trigger to fail and it's only a symptom and not the cause?
I did see this post:
Pretty much done with the schematic for the interface board.
Any corrections or comments welcome.
I replaced the BNC on the front with a 4 pin Fischer connector and wired it up to the J1 video output and a small DC-DC to convert the +BATT to 5V for the external RunCam FPV DVR. Works OK on the bench. Produces .avi files. The DC-DC is necessary as its internal DC-DC can only take 5.5V max. and I didn't want to load the ISG's 3.3V. BTW the +5V test point goes to J2 and nowhere else.
which tells me the triggers are used for some sort of signal conditioning used in the connection to the FPGA? Unsure if that failure would cause the screen and rest to completely not be functional...