I have purchased this laser with a driver from Ali. I connected the laser to the driver and the driver to a 12V DC and the TTL to 5V (which I then disconnected since the applying 5V to TTL actually turns the laser off). When I first turned power on, the laser worked fine and I was able to burn some paper for about 60 seconds before turning it off. Then when I tried to turn it on later, it no longer worked. (I can no longer return the laser since I had it home too long before getting around to testing it) I tried pulling down the TTL by shorting its pins first through a resistor, the directly, leave them floating, apply 5V to them... but nothing.. the laser no longer turns on, only the fan on it spins.
If the problem is in the driver board then I could just buy a new one since it costs only ten bucks. But how do I test that the laser itself is working fine? I was thinking about taking a PSU from an old computer and connecting the laser to the 12V DC output from the PSU. Computer electronics are very sensitive, so the PSU must have a nice, clean and smooth 12V output right? Will that work?