My first complete electronics troubleshooting and repair is my Power Designs TP340A bench power supply.

Basic specs:

• Three independent isolated power sources
• Source A & B can do 0-32v at 1A. They can be operated independently, or as a bipolar tracking supply.
• Source C can do 0-15v at 2.5A, and 0-5v at 5A.
• I’ll add the stability and ripple specs once I’ve verified the performance of my supply.

It took me a while, but I finally got it to behave properly and I have been putting it to good use.

Blog posts on my refurbishment and repair

• Power Designs TP340A Repair/Refurb
• Power Designs TP340A PSU Troubleshooting & Repair
• Power Designs TP340A Continued and Concluded
• Power Designs TP340a Knob Upgrade

The unit was in great physical condition, but it did still benefit from a little cleaning up.

• “permanent marker” yielded to isopropyl alcohol and a melamine sponge.
•  Tape/label residue was taken care of with some Goo Gone.
• I also use a combination of approaches to tidy up some of the blemishes on the front panel that I think were minor corrosion of the aluminum.
  • Pink eraser
  • Melamine sponge
  • Rough end grain of a piece of bamboo worked with the grain of the brushed aluminum.

There are still some scratches on the aluminum and the plastic meter lenses. I may try and polish them out if I think I can do so without making things worse, but otherwise, I’m happy with it.

Resources

• Power Designs TP340a TP343b Operating and Service Manual.pdf There are a few versions of this floating around. This one is the best quality, but it could be better. The schematic is legible, but barely so.
• EEVBlog thread on my project.