Hello. I'm having trouble with my Analog/Digital Trainer Pad-234A. The 5V output is not working right. When I power on the trainer, the +12V and -12V outputs work but the 5V output does not, the indicator light is not on and it's only outputting about 1.4V. I've tried changing the fuse and that didn't work. I think the voltage regulator needs to be fixed or replaced. How would I go about doing that? Thanks.