Power Button not working on a ML Prep

A lab in Houston picked up a ML Prep second hand. They were going through calibration and out of the blue the unit stopped turing off. They then physically unplugged it, plugged it back in and it would not turn on… I went over as a favor(as we never serviced Preps) to see what we could do… not sure if this is a common problem.
Pretty sure traditional service routes are limited for them.
We dont have a dog in the hunt, just throwing out to the communidty if anyone has seen this.

I saw a posted Vantage problem with this and the buttons are similar.

I haven’t heard of this one before.

Probably not what is going on, but try resetting the integrated computer—in the back there is a little hole above the model/serial number label. Use a paper clip or something to push the button inside that hole. See if that does anything.

If that doesn’t, not sure what to say.

If this was a direct purchase, the right step would be to start a ticket with product support, but we don’t currently do service/support for resold/used units.

I can’t remember if these are easily accessibly on the Prep, but might be worth checking fuses as well. Just be sure not to dig into the instrument unless you are comfortable and familiar with general troubleshooting. Beyond that, be sure to unplug any USB that may also be in the instrument before turning it on just in case.

Outside of Prep-specific troubleshooting, it sort of sounds like there’s just an open connection rather than a software glitch or fried board somewhere. Not being able to turn off while already on, and unable to turn on while off points toward the switch itself being faulty before anything else.