New to the group, but I deal with power supplies all of the time.
It sounds like you've got some soldering issues, but just in case check all of these.
First thing is to check you voltmeter and make sure that it is actually displaying the voltage correctly. If you another voltmeter handy just check the same voltage with it as well and see if you get a different result. If you don't have another voltmeter available then you could check the voltage on a 9V battery and see if you get 9 Volts.
If the voltmeter checks out, then check your powersupply and see if it has the correct output. If you are using an old PC power supply you should get -5, +5, +12, -12, and ground. Most of the new supplies also have a low amp line that is 3 volts or something - I haven't had to check that one in a while so I don't remember the value.
If the power supply checks out, then you can turn to your board. Look for any obvious solder goofs and fix them. Desoldering braid will help remove the excess solder. Check the traces and make sure they were etched completely. Check to make sure any diodes or electrolytic capacitors that were used were put in in the correct direction. If that doesn't get it then you will have to go through component by component.
Good luck