New build with recycled parts on a ridiculous budget 120cm*60cm work area

[Clive S]

Clive - the doc says "12-24V optional". I'm pretty sure that I've seen someone else talking about a similar BOB where 5V supplied the board but there was no analogue out without the extra supply. But it could have an internal regulator supplying 5V if you do use the higher-voltage supply, I guess. Docs on this Chinese stuff are a nightmare! Personally, I'd start with the 5V connected to the +5V terminal and begin testing. My first BOB was a ZP5A which was broadly similar but no analogue out, so haven't played with the one in question. OP has 5V and 12V available so at least it won't mean an extra PSU either way.

Hi Neale I have one of these bobs that I have been playing with linuxcnc and mpg's It fooled me at first. but I have just fired the bob up from a usb port for the 5V result nothing on the input pins. then I applied the 12-24v and hey presto volts on the input pins.

edit: there is a red led, lit when the 12-24v is applied it is next to the input pins