Note. Picture taken after the display light was repaired
Problem: The unit did not turn on properly, relay did not click. Light in display was bad.
The unit was in great looking shape, inside as well, which was densely packed with PCB. Searching the web for common failures for the unit, indicated that bad solders in the powersupply was a typical problem.
But there was a small problem. While you could easily access the PCB underneath the output stage, it required close to a complete disassembly to get underneath the powersupply PCB, which was kind of difficult. I almose gave up due to the amount of work required of the disassembly, not knowing if that was the problem, but luckily I decided to carry on:
This was the worst solder of them all, belonging to a voltage regulator. I gave nearly all solders in the powersupply a fresh-up though, and checked most of the components. This cured the problem and the unit worked flawlessly.
Finally, there was a cosmetic problem. The display light was uneven due to a burned out bulb. From what I could read on the net, it's a typical problem for similar NAD displays. New (original) light bulbs would burn out after a couple of years. Lacking other replacements, I dediced to give white LEDs a try instead:
Before and after NAD display light repair/modification
After some adjustments the led light was actually very good, though more blueish in the color. The leds should survive until the end of the world, and as an extra bonus, they consume less power and generate less heat. Notice that I cut the lens of the leds to make them unfocused.By Lars Ole Pontoppidan, Jan. 2006