I have a hobby cnc pro v.1 board. I have had it for a while but never really used it. I have been working on a Joes cnc for a long time. Board worked year and a half ago. I got the machine jogging not much else. I was running 24vdc power supply. I am running 40vdc now. I wanted to double check everything on the board, vref, ect.
Now I only get .2v on the 5v line (Also getting a dead short between them). Checking between the neg on TB6 and 5v pad.
On each of the Vrefs I only get .015v. I have jumper 4 removed like you are suppose to.
I took board inside to check it. I wanted to check the voltage regulators. I hooked it up to a regulated 12v / 1.25a wall wart to check 5v line. It drug the power supply to down to 9v. The voltage regulators got really hot really fast. Within 6 seconds they were hot enough for me to smell them. Lucky for me I was right over the board. No visible damage to any chips. I am assuming the v-regs have gone bad internally.
How do I know if it damaged the driver chips? or U8 or U9? Any way to test the V-regs without power?