SR-16 not powering up?

I have an Alesis SR-16 that won’t power up. I did a reset on it and it worked for a few minutes and then it shut off again. I also looked at the solder joints and everything looks good.

Any ideas on what it could be?

It could be something simple, start from the easy stuff and check VOLTAGE AND POLARITY OF POWER SUPPLY.
Was it working before?
Did you just got it and it does not work?
Good luck, Keep posting if you get it working!

I bought it as a repair. I received it and it wasn’t working, did a factory reset and it turned on. Then I turned it off and now it won’t come back on at all…