I was using the 5 volt for a logic trigger and shorted the 5volt to the driver ic heatsink. I blew U9 and replaced it with an older one from a previous build. Now the U5 is getting hot and no hiss from the motors. I can only get 1.5 or so on the 5 volt test pad and it drops steadily as i test it? help I think i posted this in the wrong place before sorry
Interesting! I checked on a PRO board, and the driver IC heatsinks are NOT electrically connected to any pin that I could find, and I checked using the Ohm scale, so even if it was 10M Ohm, I’d have seen something on the meter.
Nevertheless, something blew somewhere.
What board do you have, so I can better direct you to some things to check.
If you plug it in and quickly check the voltage at the FAN connector, what do you get as a reading? (it SHOULD be 24 VDC).
Did you double-and-triple check that nothing dropped on the board and that nothing has ‘stuck’ to the bottom of the board causing any shorts?
I checked i have no electrical connection to the heatsink. Now i dont know what i hit. The board was in a plastic container with some wires going out and when i closed it it shorted. I have the pro board 4axis. The fan connection give a reading of 17.7 and climbs to 19.6 in about 45 secs.