A couple days ago I found a couple of burnt capacitors on two of my cards. One was on the 1020-0 clock card and the other was on the 1030-0 computer interface card. It's funny because the machine was still working fine.The only problem I was having with the machine was when I would run it at 50% rapid it would vibrate. I purchased some new cards to replace the bad ones. I removed all of the other cards and inspected them for damage and could not find any. I also tested the voltage on the DC power supply and I get 12.17 volts on DC+, 12.13 volts on DC-. On the 5 volt side I get 5.13 volts. Dose anyone know what can cause this to happen. Also is there any thing else that I should test before installing the new cards? I really would hate to burn these cards because of some other problem on the machine. Almost forgot the machine is a 1989 VMC 40 with a CNC 88 Controller.

Thanks for the help.