The NAD 7020 is a humble machine with only 20 watts per channel, but carefully designed to bring excellent sound on a budget – such as my parents’ circa 1980, which is how I came to know this 7020 growing up. Now, after 20 years of sitting in a closet, it’s made its way to me for a restoration.
Restoration
Today in Amateur Electronics Repair, it’s the NAD 7020 receiver my parents bought c.1980. After 20 years of disuse, some of the channels were getting flaky. Fortunately the 7020 (and 3020 amp it’s based on) is well-regarded and commonly repaired, so with the help of some new tools and helpful internet strangers, I got it back into service.
Riley assists with cleaning out the cobwebs. Several of the electrolytic capacitors (light purple) will have dried out and failed.New desoldering gun makes it trivial to remove them.New caps waiting to go in. I replaced almost all of them, for both preventative maintenance and improvements in sound quality and heat tolerance.The phono board, recapped with Nichicon FG and Wima film caps.Recapping the main boards that are wired in, and cleaning the switches and knobs.The recapped power board. The middle of the board is black - evidence of overheating in its past. The new components are rated higher to avoid this.The cap that used to be in that spot. Clearly failed, with a very high ESR. About one in seven of the old caps were out of spec.Dim bulb test, to make sure I didn’t introduce any shorts into the power supply. The bulb is in series with the radio, so if I had, the bulb would have lit up instead of the stereo going boom.It works! The dial even lights up on the original bulb, which I had never seen it do before. Here’s to 20 more years of tunes.
