You really want to check the 5 volts for ripple. While a scope is by far the best method, you can do a poor man's version of testing with a decent meter. Put it on the lowest AC range and measure from 5 volts to ground--cheap meters will give you really wacky readings, like 10 volts for example. If you have another machine you can compare the readings between known good and unknown.
While not as cool as an eyelet press, you can put together the tools to do eyelets for about $50.